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Democratic candidates for state representative of the 24th Middlesex District tackled the issues during a forum Monday night sponsored by the Belmont League of Women Voters.
Democratic candidates for state representative of the 24th Middlesex District tackled the issues during a forum Monday night sponsored by the Belmont League of Women Voters.
Margaret Hegarty and Robert Reardon, both of Belmont, and Cambridge resident David Rogers each took questions from the audience at the Chenery Middle School, with subjects ranging from involvement in the district to the state's income tax rate.
The state's primary is Thursday, Sept. 6. The winner of the Democratic contest will go on to face Republican Tommasina Olson and independent candidate Jim Gammill, both of Belmont, in the November election.
The 24th Middlesex includes Belmont, five precincts in southeastern Arlington and two precincts in North Cambridge.
In the district
Candidates were asked about their most recent involvements in the 24th Middlesex.
Reardon said Belmont and the district are his home and an area he cares deeply about.
"I certainly try to stay as active as I can within the district," said Reardon. "Starting from the day I graduated from Belmont's public schools and I remain just as involved in all my commitments."
Reardon said he was twice elected a Town Meeting member, has coached numerous local youth sports leagues and teams within the district and worked as a legislative intern under former state Rep. Will Brownsberger, who is now in the Senate.
"I worked day in and day out in regards to the issues Belmont, Arlington and Cambridge face," said Reardon.
Hegarty, also a lifelong resident of Belmont, is a current Town Meeting member and ran for town clerk in 2010. Because she is an involved parent, Hegarty said she is a frequent school and library volunteer, as well as a Girl Scout leader.
"My career is largely involved with public service," said Hegarty. "Much of my recent law practice has been a lot of pro bono work for friends and neighbors in this community. Work that I established early on in my career as an attorney, I continue to give back to the community."
Rogers said he serves regularly on a pro bono basis as a mediator in Middlesex District Court, helping litigants resolve disputes as a means to save the state money and reduce stress.
Rogers said he also served on the North Cambridge Stabilization Committee, which considers development issues in regards to Alewife and throughout North Cambridge and East Arlington.
Job dedication
Rogers said he intends work as a full-time state representative.
"In fact, right now, I'm on a leave of absence from work, unpaid, I've used up all my sick time, all my vacation time," said Rogers. "I've had some very difficult conversations with senior management of my company because they support me, they believe in the mission I'm pursuing, but I'm well-liked there… They don't want to lose me."
Reardon said he would be a full time advocate for the district, which means being a fulltime representative.
"I looked over my budget and I will be more than able to survive off the salary of a state representative," said Reardon. "And therefore I will work as a full-time state representative without sideline employment of any kind that would avert my attention."
Reardon, who graduated from Bentley University in May, said he is fortunate to live in his family's home, which exempts him from many personal expenses.
Hegarty said she is the only candidate who has dedicated her life's work to public service.
"I know what it's like to dedicate a career towards helping others," said Hegarty. "And that's exactly what I will continue to do as your state representative. I am an attorney by trade and an attorney who has worked exclusively in public service. I've also worked in the State House, so I have an appreciation for the demands of this job in particular."
Hegarty said she would dedicate a full time effort, as she has during this campaign, if she is fortunate enough to be elected.
"This is the lifestyle I chose when I first embarked on my career many years ago," said Hegarty. "This isn't a shift; it's a continuation of the type of work I hope you will elect me to continue. It's been my life's work."
Candidates were asked to state their position on raising the state income tax rate from the current 5.25 percent, given some special interests groups are advocating for an increase.
Rodgers said Massachusetts has a revenue crisis and taxes were actually reduced in the 1990s from 5.95 percent down to 5.25 percent.
"I am open to tax increases," said Rogers. "First we need to look at tax expenditures, loopholes, exemptions and credits. We need to go to taxpayers with clean hands by first reforming our government, getting rid of these corporate loopholes and making government more efficient."
Reardon disagreed.
"We have to look at state government line item by line item, each budget year," said Reardon. "We need to make sure we are spending each and every tax dollar effectively. I am not going to be an advocate for an immediate tax increase."
Reardon said he's walked door to door during this campaign and met a lot people. And in doing so, Reardon said he's heard the same message quite a bit: people continue to search for work and the economy is still hurting.
"I would look at the state's spending issues and explore other initiatives such as public-private partnerships, pilot programs that have proved successful in other communities such as Cambridge, and nonprofit tax exempt institutions," said Reardon. "There's a lot of things we can do before increasing taxes on the individual and I want to explore each and every one of those before I go and raise the taxes on the individual person, which may be hurtful considering the economy right now."
Hegarty said she does not think there's a need for increased property taxes on the local level.
"Instead, I think we should slightly increase the state income tax in a way that protects low-income and middle class workers, as well as seniors,"said Hegarty.
Hegarty said hiking the state income tax rate to 5.9 percent would potentially raise over $1.25 billion annually.


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Independence Building Boredom Busters
December 18, 2015 in All Posts, First Grade, Kindergarten, Play, Sponsored Posts
In our house there are a few "bad" words that the kids are absolutely and completely forbidden to say, like "I hate," "I can't," and "I'm bored." But that doesn't mean they don't ever say say it – in other creative ways – or feel that way when we don't have scheduled activities. How do we beat the "I'm bored's?" With independence-building boredom busters, of course!
My goal in beating the "I'm Bored's" is twofold: to find something to engage the kids AND to encourage them to find their own fun and create their own activities without adult assistance.
All you need are a few bowls or bags of craft materials and a couple of our favorite Elmer's Glue products. Your prep time is minimal but your children can be occupied for hours!
Craft Supplies
- paper (construction paper, colored tissue paper, printer paper, or magazines)
- felt or foam (precut or whole sheets)
- crayons or markers
- craft sticks or popsicle sticks
- pom poms
- googly eyes
- Q-tips
- scissors
The type of glue that works best depends on how much time you have. If you need to quickly get through an activity and clean it up in about 10-15 minutes, Elmer's CraftBond Glue Spots are your adhesive of choice. If you have more time, set out Elmer's Washable All-Purpose School Glue Sticks, which are easy to use and there are no spills or drips to worry about. If time or mess isn't an issue, Elmer's Washable School Glue will do the trick.
15-Minute Boredom Buster
If you just need to quiet the kids down and are looking for something that will engage the kids instead of zone them out, the perfect recipe is:
Glue Dots + Googly Eyes + Pom Poms
The second I put these out, the kids immediately stopped bickering and started creating games together. The googly eyes never fail to make them laugh. I thought they might make weepul-like creatures, but they ended up creating a "colony of Maow Monsters," complete with a "Maow Monster predator"(that would be the one-eyed craft sparkly craft stick thing in the pictures) and community rules and laws for their new breed of playthings.
I actually only had fifteen minutes before we had to leave the house, and the kids were upset we had to leave the Maow Monster activity behind. The first thing the kids did when we got back home was to find their Maow Monsters and continue playing their made up game in their make believe world for almost an hour. When they got bored, they returned to the materials I still had left out and began creating more toys to play with! I never heard an "I'm bored" for the rest of the day – but the best part was that they stopped looking to me to give them something to do.
30-Minute Boredom Buster
If you have a bit more time, set out:
Glue Sticks + Paper or Felt + Markers
You can also put out sequins and other embellishments. Depending on the age of your child, you can pre-cut shapes or simply leave out scissors and paper or felt.
Another fun idea is to use craft sticks or clothespins to create puppets and animals. If you're using markets to decorate your craft sticks and clothespins, we love Elmer's Painters Markers because they can mark virtually any surface. We use them on leaves to make leaf art!
This felt creature ended up being a "steed" for the Maow Monsters.
60-Minute Boredom Buster
Any of these activities could fill an hour, but if you know you need to keep the kids occupied for a longer period, whip out:
Q-Tips + Construction Paper + Liquid School Glue
When he saw this set up, my son ended up making fossils and skeletons. This was a great activity to get him to concentrate for a long time and really work to see his idea come to fruition. I don't have a snapshot of the final product, but it is so much more intricate than I anticipated it would be!
The great thing about this activity – and all the activities here – is that there are no specific end products. Your kids can spend as much or little time as they want with the materials and the only limits to what they can do are the limits they put on their own imaginations.
My favorite thing about leaving materials out with no direction is that the kids are creating something on their own and they actually are making their own toys!
What is your go to boredom buster? Share with us in the comments below!
Here are a few more great activities to encourage independent creativity:
Keep #RaisingThinkingKids and have fun!
Disclaimer: I'm thrilled to be collaborating with Elmer's to share our easy activities and crafty inspiration for busy moms and families like ours who want to spend more time unplugging and reconnecting. We receive lots of glittery goodies as part of this relationship, but as always, all opinions are our own.


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The race to succeed McClendon already is heating upSeptember 5, 2015
If Ruth Jones McClendon had announced her retirement from the Texas House two years ago, there would have been an obvious heir apparent in place: Ivy Taylor.
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Volume 38 Issue 1, January-February 1998
Select All Articles
Epistatic and environmental effects on foreign gene expression in cotton (Gossypium hirsutum L.) could influence the breeding, stability and, in the case of pest resistance, efficacy and durability of the foreign gene. This study was undertaken to characterize the expression an segregation of two foreign cryIA genes in a range of insect-resistant cotton lines derived in three backgrounds. The cryIA genes encoded insecticidal proteins from the bacterium Bacillus thuringiensis spp. kurstaki. The transformed cotton lines, MON 81 expressing the cryIA(b) gene and MON 249 expressing the cryIA(c) gene, were crossed to 14 cotton isolines with five different insect-resistance traits. CryIA gene expression and variation were examined in terminal leaves of 2293 F2 progeny and subsequently in 12 F2:4 lines [cryIA(b) only] in field experiments conducted at two locations in Texas. CryIA gene expression was variable and influenced by genetic and environmental factors. Site-of-gene-insertion and cotton-background effects were significa sources of variation for the cryIA gene. Significant epistatic and/or somadonal effects increased plant-to-plant variation and caused cryIA gene expression to behave as a quantitative trait. Environmental effects, between and within locations and over time, decreased parent-offspring correlations of mean cryIA gene expression between individuals from the F2 and F2:4 generations. Gene dosage at the cryIA locus influenced insecticidal protein concentration in F2 populations with the cryIA (b) gene insert—homozygotes produced 14% more CryIA(b) protein than hemizygotes. The CryIA phenotype segregated as a simple, dominant Mendelian trait. However, non-Mendelian segregation occurred in some lines derived from MON 249. Expression of cryIA genes in cotton lines was influenced by one or more of the following: site of gene insertion, gene construct, background genotype, epistasis, somaclonal mutations, and the physical environment. These results indicate that appropriate evaluation and selection procedures should be used in a breeding program to develop new cotton lines with pest-resistant traits conferred by foreign genes. Moreover, that a practical backcross breeding program could be used to develop cotton cultivars combining one or more pestresistant traits from foreign and native gene sources.
Part of a dissertation submitted by the senior author in partial fulfillment of the requirements for a Ph.D. degree at Texas A&M Univ.
Transgressive segregation is often observed for quantitative traits in the offspring of both intraspecific and interspecific hybrids. Understanding its genetic base is important for the improvement of these characters. In this research, we began with four indica cultivars, 5002, Zhu-Fei 10, HA79317-7, and Zhen-Long 13, all having similar tiller angles. F2 populations were derived from the crosses 5002/Zhu-Fei 10 and HA79317-7/Zhen-Long13, and divergent selection for tiller angle was practiced in each F2 population. As a result of selection, two types of true-breeding phenotypic extremes were obtained, one with larger tiller angle and the other with smaller tiller angle. for loci contributing to variation in tiller angle, the alleles of similar effect were proved to be dispersed in the original parents and associated in the extreme selections. Crossing two extreme strains derived from different original crosses revealed new transgressive segregation in the F2, demonstrating that different loci controlled tiller angle in the two cross combinations examined in this study. When the extreme phenotypes were crossed with each other, strains with the largest tiller angle represented recombinants containing all increasing alleles from the four original parents. Four quantitative trait loci (QTLs) were inferred to be responsible for the transgressive segregation in the two original crosses. The intervarietal transgression could be explained by complementary action of additive genes that had been dispersed among the original parents. To test for allelism of the QTLs for large tiller angle and a previously identified major-gene mutant, lazy (la), one of the extreme strains from the second cycle of selection having the largest tiller angle was crossed with the lazy growth mutant, H-79. Results indicated that la was not allelic to any of the QTLs. Breeding experiments demonstrated that multiple crossing followed by one cycle of selection could be used to accumulate into one strain the genes that were dispersed in the parents.
A stem-tip inoculation procedure has been successfully used in divergent selection for resistance to Sclerotinia trifoliorum (Eriks) on alfalfa (Medicago sativa L.). One unreported observation made in early studies was that lesion development was not continuous for some alfalfa plants over the 14-d incubation. A more in-depth study of disease development was needed to quantify the variability, and the stem-tip inoculation procedure was modified for this purpose. Inoculated stems were placed in plastic sleeves and marks were made daily on the plastic to show the development of necrosis over time. Eight plants previously selected for their higher levels of resistance and eight plants selected for minimal resistance (susceptibility) developed necrosis after 14 d in the plastic sleeves, which was similar to that measured in earlier studies. The length of the lesion on susceptible plants was described by a linear equation with 0.9 to 1.3 cm of necrosis d−1. Six of the resistant plants stopped the lengthening of the necrotic stem lesion about 8 d after inoculation while two of the resistant selections continued linear development at rates much less than that measured on the susceptible selections. When the necrotic region stopped developing, a dark border usually developed between the green and necrotic tissues which was not seen when disease continued to develop. Statistical analysis suggested disease resistance might be effected by either of two qualitatively different systems.
Cooperative investigation of USDA-ARS and Mississippi State University, Mississippi Agric. and For. Exp Stn. Journal Series no. J 8974.
Two types of resistance responses have been identified on alfalfa (Medicago sativa L.) for Sclerotinia crown and stem rot caused by Sclerotinia trifoliorum (Eriks) following st em-tip in oculation. A plant with the Type 1 resistance stops the lengthening of necrotic region on the stem about eight days after inoculation, but a plant with the Type 2 resistance continues slow expansion of necrotic region for the duration of the 14 d test. This research determined the levels of resistance in progenies from crosses of selections with same and different types of resistance to Sclerotinia, from crosses of resistant and susceptible selections, and from self-fertilization of selections. The daily development of disease was measured from four to 14 d after inoculation on progenies from a diallel of six resistant selections and from a factorial cross of four resistant and four susceptible selections. The crosses among selections with Type I resistance produced progenies only with Type 1 resistance. Crosses of selections with Type 1 and Type 2 resistance produced four progenies with Type I resistance and four progenies with Type 2 resistance. Selfing the four selections with Type 1 resistance resulted in three progenies with Type 1 resistance and one with Type 2 resistance. Crosses of susceptible plants and those with Type 1 resistance resulted in low levels of Type 2 resistance. Selfing generally decreased the level of resistance in the resistant selections. For development of synthetic varieties, parents should be selected with high levels of Type 1 resistance and for self-sterility.
Cooperative investigation of USDA-ARS and Mississippi State University, Mississippi Agric. and For. Exp Stn. Journal Series no. J 9033.
In hexaploid wheat (Triticum aestivum L.) disease resistance genes transferred from alien sources are often associated with undesirable traits. Replicated trials using near-isogenic lines of spring wheat 'Seri 82' were conducted for 2 yr under non-moisture stress and simulated moisture stress conditions to determine the effects of the 7DL.7Ag and 1BL.1RS translocations [from Agropyron elongatum (Host) Beauv. and Secale cereale L., respectively] on grain yield and related traits. Mean grain yield of the 1B lines was significantly higher (3.2%) than that of the 1BL.1RS translocation lines in non-moisture stress trials, but not significantly higher in the moisture stress trials. The mean grain yields of the five highest yielding reconstituted Seri 82 genotypes (1BL.1RS) were significantly lower than that of the genotypes without the 1BL.1RS translocation in non-moisture stress (3.2%) and moisture stress (5.2%) conditions. Incorporation of the 7DL.7Ag translocation caused a significant increase (9%) in biomass at harvest in non-moisture stress trials. The mean grain yields of the five highest yielding 7DL.7Ag lines were significantly higher (8.2%) than the reconstituted Seri 82 genotypes in non-moisture stress conditions and more than 16% lower under moisture stress. Lower grain yields of the 7DL.7Ag lines under moisture stress could be due to their excessive pre-heading biomass production. Several yield-related traits of the near-isogenic genotypes varied significantly. Presence of each translocation caused lateness and, when present together, the 1BL.1RS and 7DL.7Ag translocations delayed heading and maturity by 7 and 5 d, respectively. The genetic background of the recipient wheat can affect the utility of a translocation.
Despite concern about genetic vulnerability, little is known about the recent changes in the genetic diversity of upland cotton (Gossypium hirsutum L.). The objectives of this study were to determine the trends in the genetic diversity of upland cotton in the USA during the last 25 yr and to investigate probable causes for these changes. Two estimates of genetic diversity, coefficient of parentage (rp) and field uniformity (ri; rp weighted by the proportion of the hectarage occupied), were made for cultivars occupying over 1% of the hectarage within a region (Southeast, South-central, Southwest, and West) from 1970 to 1995 at 5-yr intervals. An average of 17 (range = 8–46) cultivars accounted for 97% of the cotton hectarage within a region. Regional rp values were relatively stable at 0.12 to 0.15 from 1970 to 1990 and then sharply increased to 0.20 in 1995. Higher rp values in commonly grown cultivars than in released cultivars indicated that much of the genetic diversity in cotton remains unused by growers. Field uniformity (ri) remained at about 0.30 for all regions during the past 25 yr because increases in rp were matched with an increase in the number of cultivars grown and/or a decline in the proportion of the area planted to any single cultivar. The frequent use of several parents for the creation of new cultivars and the planting of only a small portion of the available cultivars has led to a high level of genetic uniformity.
Methods that could predict F1 maize (Zea mays L.) hybrid performance with some accuracy prior to field evaluation are of particular interest. This study was conducted to evaluate the efficiencies of the conventional additive model based on the general combining ability (GCA) as control and of three different predictions of the specific combining ability (SCA). The first approach was based on the hypothesis that the degree of SCA expressed by a single-cross is related to the marker distance between its parental lines. The second approach was based on a factorial regression model of interaction, where markers were used by means of principal component analysis to generate covariates for SCA. The third approach was adapted from the best linear unbiased prediction (BLUP) of SCA, where covariances between hybrid SCAs were estimated with marker data. Efficiencies were evaluated by means of a cross-validation procedure for silage performance of a 21 by 21 half-diallel population among maize inbreds. This procedure was applied to (i) all hybrids and (ii) hybrids between unrelated parents only. In situation (i), introducing a distance term in the model accounted for up to 73.6% of the variation in the hybrid performance observed, whereas the corresponding efficiency of the GCA model was 63.4%. The introduction of a distance term did not modify prediction efficiency in situation (ii) whereas the use of the factorial regression model or the BLUP approach led to moderate improvements. These results suggested that efficient approaches can be proposed to predict hybrid silage yield and that prediction of SCA is mostly justified in situations where coancestry among inbreds is unknown or only suspected.
Most genetic models assume absence of epistasis while estimating components of genetic variation. However, epistasis when present introduces bias. These biased estimates affect the progress in a breeding program since they influence the choice of breeding methodology. The objectives of this study were to determine the significance of epistasis in the inheritance of pod yield and related traits in 15 peanut (Arachis hypogaea L.) cultigens, and to estimate the additive and dominance variances for the traits not influenced by epistasis. Two cultigens and their F1 hybrid were each crossed to 15 cultigens from 13 countries, representing three botanical groups. The experiment was conducted in the 1992-1993 post-rainy and 1993 rainy environments at the ICRISAT Asia Center, Patancheru, India. The deviations were analyzed to detect epistasis of 11 traits. Epistasis affected the expression of eight traits in both environments. Environments interacted more strongly with epistatic gene actions than with additive or dominance gene actions. Expression of epistasis was influenced by genotypes and environments, indicating the need for more genotypes and environments for effective detection of epistasis. Evidence for additive genetic variance and lower levels of partial dominance for canopy breadth and additive and dominance variances and complete dominance for shelling outturn was obtained in the post-rainy environment.
ICRISAT J.A. no. 1981.
Phytophthora sojae (Kauffmann and Gerdemann) is the causal agent of phytophthora root and stem rot of soybean [Glycine max (L.) Merr.]. disease outbreak infavorable environmental conditions has the potential to inflict 100% yield loss. Soybean accessions fromcentral China offer unique genetic variability and are potential sources for novel genes conferring phytophthora resistance. Approximately 500 accessions have been classified for reaction to races 1, 3, and 7 of P. sojae. Eighteen accessions were selected that were resistant to races 1 and 3 and susceptible to race 7. RFLP markers linked to resistance alleles were used to compare the accessions to isolines with known Rps alleles. Restriction fragment length polymorphism (RFLP) results were supported with greenhouse hypocotyl inoculations with zoospores of races 1, 3, 5, 8, 12, 13, and 25. One plant introduction (PI) was found likely to possess Rps1a, five possibly possessed Rps2, seven could carry Rps3, and four were found possibly to possess Rps4. Evidence of multigene combinations were detected in eight accessions. Unique RFLP bands and hypocotyi inoculation reactions were discovered in PIs 567343, 567530, 567572A, 567574A, 567583A, 567764, and 567766, implying possible presence of novel Rps alleles. Knowledge of which Rps allele combinations are present in these accessions will allow for integration of the novel resistance into modern cultivars.
Research supported by the Illinois Soybean Program Operating Board and the Illinois Crop Improvement Association.
Common rust (Puccinia sorghi Schw.) is a major pathogen of sweet corn (Zea mays L.). Recurrent selection may be useful for improving resistance to common rust. The objectives of this study were to (i) evaluate three sweet corn populations (Minn11, Minn14, NECDR) after three cycles of full-sib recurrent selection for resistance to common rust evaluated 40 d after pollination (DAP), (ii) determine if selection increased resistance 21 DAP, and (iii) determine if selection affected agronomic traits related to plant architecture, maturity, and yield. Cycles 0 to 3 from each population were evaluated under artificial rust infestation in 1989, 1990, 1993, 1994, and 1995, and without infestation in 1994 and 1995. Percent leaf area infected declined linearly from 37.0 to 8.2% in Minn11 (R2 = 0.98) and 57.0 to 9.9% in NECDR (R2 = 0.98) evaluated 40 DAP, and from 22.5 to 7.8% in Minn11 (R2 = 0.89) and from 22.8 to 10.0% in NECDR (R2 = 0.91) evaluated 21 DAP. Population Minn14 tended to have decreased percent leaf area infected over cycles, but the response was not significant because of cycle × year interactions in each experiment. Most agronomic traits decreased linearly over cycles except for ear weight/stover weight ratio in Minn11 and NECDR, and silk delay in Minn14, which increased linearly. In general, plants tended to be more compact and flower earlier over cycles. Selection for plant type, ear weight, and flowering time should accompany selection for resistance to common rust.
Research supported by Hatch Funds allocated to the Wisconsin Agric. Exp. Stn., the College of Agric. and Life Sci., the Graduate School, Univ. of Wisconsin-Madison, the Univ. of Wisconsin Pioneer Hi-Bred Plant Breeding Fellowship awarded to B.G. Abedon, and The Midwest Food Processors Association. Submitted by the senior author as partial fulfillment of the Ph.D. degree.
Research in Europe and the USA indicated that interference between plots in cultivar trials can distort yield and result in misleading conclusions from yield comparisons. Field trials were conducted at Swift Current and Saskatoon in 1993 and 1994 to determine if interplot interference is a concern in the wheat growing region of Saskatchewan. Four spring wheat (Triticum aestivum L.) cultivars, Biggar, Oslo, Genesis, and Glenlea, were grown in four-row plots in a diallel competition treatment design, with the competition treatments applied randomly to each of the eight replications. Generally, yield was distorted from pure stand yield when flanking plots differed for height. On average, yield was reduced 0.34% per centimeter increase in height of the flanking plots, and the reverse occurred when height of the flanking plots was less. Plots of the short cultivars Biggar or Oslo flanked by the tall cultivars Genesis or Glenlea yielded less than when flanked by themselves, and the reverse occurred when the tall cultivars were flanked by the short cultivars. Interplot interference affected spike density in the same fashion, did not significantly affect height, and was inconsistent with regards to kernel weight. It was concluded that when plots differ for height, yield distortion can occur in the Saskatchewan wheat growing region.
Part of a PhD thesis submitted by F.R. Clarke.
The literature reports that evaluations over a number of growing seasons are required to identify stable disease resistance in rice (Oryza sativa L.). CIAT's Rice Breeding Program alms to develop lines with stable resistance; therefore, the knowledge of how long a germplasm should be assessed before being used in crosses is important. For this research, 69 commercial cultivars grown in Latin America and the Caribbean were evaluated during 11 growing seasons in a 'hot spot' site for the four most important diseases of rice: leaf and panicle blast (caused by Pyricularia grisea Sacc.), leaf scald [caused by Microdochium oryzae (Hashioka & Yokogi) Samuels & I.C. Hallett syn. Gerlachla oryzae (Hashioka & Yokogi) W. Gams syn. Rhynchosporium oryzae (Hashioka & Yokogi)], and grain discoloration (caused by species of Sarodadium, Bipolaris, Alternaria, Gerlachia, Fusarium, Phoma, Curvularia, Trichoconiella, and Pseudomonas). Cultivar mean disease severity (M), its response to increase in disease pressure (b), and the standard deviations from the regression (Sb) were calculated. Eleven evaluation seasons were considered as the most reliable period, in which an ideal set of 13 cultivars was identified based on their disease resistance stability (M, b, and Sb values). To identify the minimum number of seasons required to assess stability of resistance, simulations were made with these 13 cultivars and the 11 seasons and the coincidence in selection and the number of misclassified entries were calculated. The M and b correlation values and the number of misclassified entries suggested that seven consecutive growing seasons (two per 12-mo. period) are necessary to identify germplasm with stable reaction to leaf and panicle blast, leaf scald, and grain discoloration.
Soil salinity is a major limitation to legume production. We evaluated specific soybean [Glycine max (L.) Merr.] genotypes to identify a salt-tolerant soybean-Bradyrhizobium system, and to determine by grafting experiments if the scion or the root was responsible for salt tolerance. The effects of three levels of salinity (0, 30, and 60 mM NaCl) on nitrogenase activity (acetylene reduction), nodule number, nodule dry matter, and growth of four soybean genotypes (Williams 82, PI 416937, DR-1 [an Egyptian cultivar], and NOD1-3 [a hypernodulating mutant selected from Williams]) were investigated in hydroponic cultures and growth chamber environments. Salt stress significantly inhibited nitrogenase activity, nodule number, and dry matter accumulation per plant of all four cultivars. The detrimental effects of salinity on nodulation parameters and dry matter accumulation were most pronounced for NOD1-3 and Williams 82, intermediate for DR-l, and less marked for PI 416937. Self-grafted NOD1-3 plants showed 50 to 62% inhibition in nodulation responses (activity, number, mass) while grafting of P1416937 scions to NOD1-3 roots resulted in less than 7% inhibition by salt. Nodule number on PI 416937 roots was greater when grafted to NOD1-3 scions (relative to self-grafted PI 416937 plants), confirming a shoot role in autoregulation of nodule number. Conclusions are that shoot factors are of primary importance in determining salt-tolerance of the PI 416937 genotype and that hypernodulation expression in the mutant is negatively affected by salt treatment.
Stachyose, sucrose, and other non-reducing soluble carbohydrates are associated with the onset of desiccation tolerance during seed development and with seed storability. Mature soybean [Glycine max (L) Merr.l seeds contain several galactosyl cyclitols in addition to sucrose, stachyose, and raffinose, but except for galactinol, the accumulation of these galactosyl cyclitols has not been reported for developing soybean seeds. Fifteen soluble carbohydrates including members of the raffinose, galactinol, galactopinitol, and fagopyritol series were analyzed in extracts from axis and cotyledon tissues of seeds and zygotic embryos matured in planta and in vitro. Galactopinitol A, galactopinitol B, and fagopyritol B1 accumulate in axis tissues of developing soybean seeds in planta in association with the onset of desiccation tolerance, yellowing of axis tissues, and in parallel with stachyose accumulation. Galactopinitol A, galactopinitol B, fagopyritol B1, and stachyose also accumulate in parallel in cotyledons in planta and in axis tissues during in vitro growth of zygotic embryos at 15 and 25°C. Axes of soybean seeds matured at 25°C contained higher concentrations of sucrose, raffinose, D-pinitol, D-chiro-inositol, fagopyritol B1, and total soluble carbohydrates than axes of seeds matured at 18°C. Soybean seeds accumulate mostly galactosyl pinitols and only small amounts of free pinitol. In future work, It would be of interest to determine if gaiactosyl cyclitols may substitute for the role of stachyose in providing desiccation tolerance and prolonged seed storability.
Grain weight largely determines the end-use quality of barley (Hordeum vulgare L.). In six-rowed types, central spikelets commonly bear heavier grains than lateral spikelets. However, the extent to which such differences in weight are influenced by source availability remains unclear. Field experiments were carried out in nine rainfed trials of northeastern Spain and showed large variability in grain weight. Three six-rowed genotypes were used: Barberousse, Orria, and Plaisant. Sink strength of mainstems was decreased by half at anthesis by sterilizing 50% of fertile central and lateral florets. Variation among spikelets in grain growth parameters [maximum grain filling rate (GFR) and grain filling duration (GFD)] and in final grain weight was evaluated in control and sink-reduced spikes. Central grains outweighed lateral ones in control spikes from 7.3 to 14.8 mg across trials. Absolute differences in weight increased progressively in those trials favoring larger grains, although lateral to central grain weight ratios (L/C) remained fairly constant, with an average value of 0.77. This advantage of central grains was mostly caused by higher GFR values. A 50%-reduced sink increased grain weight of both central and lateral spikelets similarly and did not diminish the absolute differences in weight found in control spikes. This result suggests that central grains have a greater intrinsic potential weight. While grain yield was partially source limited in all environments, lateral grains exhibited on average a major degree of source limitation (24.2%) than central grains (19.1%). Sink reduction increased grain weight of both central and lateral grains by stimulating GFR in all trials, and also by lengthening GFD in poor rainfed environments.
This research was partially supported by INIA 9680-92 and CICYT AGF95-1008-C05 grants, Spain. J. Voltas is a recipient of a grant from the Comissionat per a Universitats i Recerca (Generalitat de Catalunya).
Waterlogging is a serious environmental stress on winter wheat (Triticum aestivum L.) grown in the Gulf Coast region. We hypothesized that waterlogging tolerance differs in currently available lines and cultivars and that suitability of physiological parameters to distinguish yield responses could be evaluated. Three types of studies were conducted: a 2-yr greenhouse study of eight cultivars, a 4-yr irrigated field study of 20 cultivars and breeding lines, and a 3-yr field study of six cultivars under rain-excluding shelters which allowed comparison of performance under waterlogged and well-drained conditions. In the rainshelter study, waterlogging caused a 45% decrease in grain weight, resulting from a 45% decrease in number of kernels and a 5% decrease in kernel weight. Cultivars differed for grain yield under waterlogged conditions in the field (P = 0.1), and Coker 9877 and line LA 862A16-3-3-X yielded 32 and 33% above the mean, respectively. Greenhouse measures of photosynthesis under waterlogging were weakly predictive of yield (r2 = 0.61) and correlated to measures under well-drained conditions (r2 = 0.87). Yield was well correlated with biomass (r2 = 0.84) and root mineral content (Fe + Mn + P) (r2 = 0.94). Waterlogged yields × cultivar did not correlate with yield under well-drained conditions (r2 = 0.14) and the same differential response to waterlogging was shown for biomass and root mineral content. The negative correlation between root mineral content and yield was attributed to processes involved in the formation of a mineral plaque on the surface of the wheat roots. This emphasizes the need to explore differences in root function when selecting wheat lines for enhanced waterlogging tolerance.
Approved for publication by the Director of the Louisiana Agric. Exp. Stn. as paper No. 96-38-0176.
The establishment rate of warm-season turf and forage grasses propagated by sprigs or cuttings is of economic importance by determining not only how quickly an area may be utilized but also by influencing the extent of weed invasion. We monitored 'Tifton 85' bermudagrass [Cynodon dactylon (L.) Pers.] vegetative growth response to the application of ethephon (2-chloroethylphosphonic acid), an ethylene-producing compound, and how this treatment affected subsequent vegetative establishment. Responses of established Tifton 85 plants to ethephon treatment when compared with untreated plants included a 22% reduction in plant height, node swelling, bud swelling at the crown, terminal leaf necrosis, chlorotic striping of young developing leaves, and a 118% and 101% increase in leaf/stem fresh and dry weight ratios, respectively. Swelling of ethephon-induced buds appeared to be due to a transient arrest in sprouting. Swelled buds finally sprouted 9 d following ethephon treatment. In glasshouse experiments, vegetative cuttings taken from ethephon treated plants produced 112% more roots under a range of water stress conditions 8 d after cutting removal, and produced 10-fold higher number of tillers at 6 d after planting in soil than untreated cuttings. Tiller production in the soil establishment study was not statistically different between ethephon treated and untreated plants after 21 d. These glasshouse results indicated that it may be feasible to develop ethephon treatments that improve establishment rate and subsequent stand quality of Tifton 85 bermudagrass in field/commercial applications.
Development of maize (Zea mays L.) types that produce leaf area quickly and tolerate high plant densities could enhance yields in midto short-season environments. The leafy and reduced-stature traits each make contributions to this end, but have not previously been combined. Our objective was to evaluate the effect of plant densities on leafy normal-stature (LNS), non-leafy normal-stature (NLNS), leafy reduced-stature (LRS), and non-leafy reduced-stature (NLRS) inbreds. Twenty-one inbreds were field-grown over 2 yr at low (65 000 plant ha−1) and high (90 000 plant ha−1) densities. Above-ear leaf number, above-ear leaf area, and single plant grain yield were lower for LNS and NLNS at the high, as compared with the low, plant density, but were not affected for LRS or NLRS. The corn heat unit (CHU) requirements from planting to tasseling, and from planting to silking, as well as days between tasseling and silking, were greater under high plant density for LNS and NLNS, but were not affected for LRS or NLRS. Grain yield increased to a greater extent under high density compared with low density for LRS and NLRS than for LNS or NLNS. The LRS inbreds had a shorter vegetative period, longer grain-filling period, highest yields, and were more tolerant of high plant density than the normal-stature genotypes. These characteristics indicate potential both for increased yields and production in areas with lower CHU availability. These advantages are expected to be conferred to LRS hybrids.
Growth analysis of crambe (Crambe abyssinica Hochst. ex R. E. Fries) is important for the use of proper production practices and adequate pest management strategies. This study evaluated the heat unit requirements and quantitative characteristics of crambe growth [leaf area index (LAI), leaf area duration (LAD), yield, and total biomass] and the impact of defoliation on yield using artificial infestation with diamondback moth (Plutella xylostella L.) (DBM) in 1993and 1994 and manual defoliation in 1995. The heat unit accumulation from planting to physiological maturity was approximately 1350 degree-days (DD) above 2.5 °C. The maximum LAI and generally the maximum daily increase of biomass occurred at the onset of flowering. The yield was proportional to LAD: 238 g m−1 versus 1187 DD in 1993, 190 g m−1 versus 1010 DD in 1994, and 117 g m−1 versus 774 DD in 1995. No reduction in yield or thousand seed weight was observed in any of the infestation or defoliation experiments. The artificial defoliation experiment showed that crambe can withstand substantial injury after the start of anthesis (25–50% of leaf area lost) without a significant yield loss.
Tropospheric O3 can cause foliar injury, decreased growth, and decreased yield, whereas CO2 enrichment generally causes opposite effects. Little is known about plant response to mixtures of O3 and CO2. Open-top field chambers were used to determine if foliar responses of soybean [Glycine max (L.) Merr.] to CO2 enrichment are affected by O3 stress and vice versa. Plants were grown in 14-L pots and exposed to four CO2 and three O3 concentrations in 12 combinations. The CO2 treatments were ambient (366 μL−) and three treatments with CO2 added for 24 h d 1 at approximately 1.3, 1.6, and 2.0 times ambient. The O3 treatments were charcoal-filtered air (CF), nonfiltered air (NF), and NF with O3 added for 12 h−1 ( NF+), resulting in seasonal concentrations of approximately 20, 46, and 75 μL L−1. Foliar effects of CO2 enrichment were dependent on the amount of stress caused by O3. In the CF treatment, plants were not stressed by O3, and CO2 enrichment caused chlorosis and decreased chlorophyll. In the NF and NF+ treatments, plants were stressed by 03, and CO2 enrichment suppressed chlorosis and increased chlorophyll. Ozone decreased specific leaf weight, increased foliar N and C, and decreased C/N ratios, whereas CO2 caused opposite responses for these measures. Ozone increased foliar S and B but did not affect P or K concentrations. Conversely, CO2 enrichment suppressed foliar S, B, P, and K concentrations. These interactions between O3 and CO2 emphasize a need to consider the amount of plant stress caused by O3 in studies to measure effects of CO2 enrichment.
Cooperative investigations of the USDA-ARS Air Quality Research Unit and the North Carolina State University. Funded in part by the North Carolina Agricultural Research Service.
Previous research has shown that elevated CO2 concentrations can increase plant growth, whereas the air pollutant O3 is phytotoxic. Because elevated concentrations of these gases will co-occur, the objective of our experiment was to determine if estimates of plant growth response to future levels of CO2 and O3 require experiments to test the gases in combination. Soybean plants [Glycine max (L.) Merr. cv. Essex) were exposed in open-top chambers to combinations of O3 and CO2 from plant emergence through physiological maturity. Ozone treatments were charcoal-filtered air (CF), nonfiltered air (NF), and NF with O3 added for 12 d−1 (NF+) (seasonal mean 12 d−1 O3 concentrations of 20, 50, or 79 nL L−1, respectively). Carbon dioxide exposures were for 24 h d−1 giving seasonal mean 12 d−1 concentrations of 370, 482, 599, or 713 μL L−1. Over the season, elevated CO2 usually stimulated growth and O3 suppressed growth. Elevated CO2 usually increased partitioning of biomass to branches, decreased partitioning to pods, increased specific leaf weight, and decreased leaf area ratio. Ozone suppressed leaf and root weight ratios, increased pod weight ratios, and decreased specific leaf weight. Toward the end of the season, both O3 and CO2 accelerated reproductive development. Elevated CO2 moderated suppression of growth by O3, and the highest CO2 concentration completely ameliorated O3 effects on main stem biomass, root biomass, and leaf area. Ozone, however, limited some positive growth responses to CO2, especially at less than a doubling of CO2 concentrations. These results indicate that in order to understand the future impacts of atmospheric gases such as elevated CO2 and O3 on crop growth, their combined effects should be determined.
Ozone in the troposphere can cause plant stress, whereas elevated CO2 generally causes positive responses. Little is known of how these gases interact to affect plant response. Interactive effects on yield and seed quality of soybean [Glycine max (L.) Merr.] grown in 14-L pots were measured in open-top field chambers. Essex was tested in 1993, and Essex, Holladay, and NK 6955 were tested in 1994. Plants were exposed from emergence to maturity to four CO2 levels (ambient and 1.3,1.6, and 2.0 times ambient) and three O3 levels (0.4, 0.9, and 1.5 times ambient) in 12 combinations. Increasing O3 suppressed growth and yield, whereas CO2 enrichment stimulated growth and yield. Carbon dioxide-induced stimulation was greater for plants stressed by O3 than for non stressed plants. For example, CO2 at 2.0 times ambient increased 2-yr mean seed yield of Essex by 16, 24, and 81% at O2 levels of 0.4, 0.9, and 1.5 times ambient, respectively. Effects of O3 and CO2 on seed oil content were variable with numerous cultivar differences. Seed protein content was never affected. Elevated O3 suppressed oleic acid content in seeds, whereas CO2 increased it; the nature of the O3 × CO2 interaction for oleic acid was similar to that observed for most yield measures. Carbon dioxide-induced stimulation of plants stressed by O3 was apparently caused partly by amelioration of O3 stress. Interactions between O3 and CO2 must be considered for proper interpretation of cause-effect relationships in CO2, enrichment studies.
In an effort to conserve water applied to irrigated turfgrass sites, it is important to assess the potential for water conservation among turfgrass germplasm. Turfgrass can respond differently in evapotranspiration (ET) rate as climatic conditions change. The objective of this study was to investigate the interaction between the ET response of 61 Kentucky bluegrass (Poa pratensis L., KBG) cultivars (evaluated under controlled environment) and three equally spaced, evaporative environments (temperatures 25, 30, and 35°C, corresponding to 1.263, 1.664, and 2.261 kPa vapor pressure deficit, VPD, respectively). There was a significant interaction (P ≤ 0.001) in ET rate between the 61 cultivars and the three evaporative environments. Simple linear regression models and AMMI (additive main effect and multiplicative interaction) models were used in interpreting cultivar-environment interactions. There was wide variation in cultivar mean ET (5.36–6.82 mm d−1), in stability of cultivar ET ranking, and sensitivity to evaporative environment characterized by cultivar stability. Cultivar stability (regression coefficients) varied by as much as 60% in the change ET rate, from 1.13 to 3.16 mm d−1 kPa−1. The AMMI model revealed that the high evaporative environment (2.261 kPa VPD) interacted with cultivars in a direction opposite to 1.263 and 1.664 kPa environments indicating that relative ET rankings of cultivars are the most variable between diverse evaporative environments. Compared with ordinary analysis of variance (ANOVA), AMMI was more effective in detecting and interpreting interaction. This study indicated that (i) breeding for water conserving KBG may have limited impact for reducing irrigation requirements because most of the variation in ET (87%) is due to environment and not to the plant's pedigree, and (it) recommendations for use of specific cultivars maybe difficult because of inconsistent water use patterns and intraspecies variation in KBG that were observed in response to diverse evaporative environments that are typical of field conditions.
As the competition for water increases, there is a need to conserve limited water resources applied to irrigated turfgrass sites. Consistent with this effort is the identification of water conserving Kentucky bluegrass (Poa pratensis L.) because low consumptive water use may be important in reducing irrigation requirements by enhancing drought resistance. Low evapotranspiration (ET) rates under non-limiting soil moisture conditions have been associated with turfgrass morphology and growth characteristics that increase canopy resistance to ET and reduce leaf area components. Much of this previous research emphasized warm-season turfgrass. A greenhouse study was conducted to determine the relationship between morphological and growth characteristics in 61 Kentucky bluegrass (KBG) cultivars and comparative water use. By means of cluster analysis, the 61 KBG cultivars were categorized as either low- or high-water use cultivars based on ET rates evaluated in the growth chamber across three evaporative demand environments (1.263, 1.664, and 2.261 kPa VPD). Morphological and growth characteristics were assessed from unmowed, spaced plants and mowed turfgrass grown in fritted clay filled lysimeters. Based on single plant morphology, low-water use cultivars had 13% more horizontal leaf orientation, 6% narrower leaf texture, 13% more lateral shoots per plant, 12% slower vertical leaf extension rate, 2% more leaves per shoot, and 7% shorter leaf blades and sheaths than the high-water use cultivars. Based on turfgrass morphology from mowed lysimeters, the low-water use cultivars had 17% more horizontal leaf orientation, 10% narrower leaf texture, 15% more shoots, 4% slower vertical leaf extension rate, and 4% shorter leaf sheaths than the high-water use group. Canopy resistance to ET was not measured in this study; however, leaf angle (assumed component of canopy resistance) was the only plant characteristics evaluated under mowed conditions whose correlation with turfgrass ET exceeded 0.50 in absolute value. Differences observed among water use groups based on single plant- and turfgrass-morphology was not always consistent with the high canopy resistance to ET/low leaf area hypothesis. However, characteristics were identified which may be useful in selecting for KBG with a low-water use pattern.
Identification of water conserving Kentucky bluegrass (Poa pratensis L., KBG) is an important objective in turfgrass breeding programs. Warm-season turfgrass selections with low evapotranspiration (ET) rates have been successfully identified by components of canopy resistance to ET and leaf area. The objective of this study was to determine the effectiveness of discriminant analysis in distinguishing water conserving KBG on the basis of canopy resistance and leaf area from a population of 61 KBG cultivars. By means of cluster analysis, the 61 KBG cultivars were categorized as either low- or high-water use cases based on ET rate evaluated in the growth chamber at three VPD environments (1.263,1.664, and 2.261 kPa). Fourteen morphological and growth characteristics were assessed in the greenhouse with unmowed, spaced plants and mowed turfgrass (20-cm-diam. lysimeters). Based on single plant morphology, five- and seven-variable discriminant functions were identified that correctly classified cases into their actual water use groups with an estimated 70.5% actual error rate from cross-validation with the leave-one-out method (LOER). Compared with single plant morphology, turfgrass morphology was more efficient in requiring fewer predictors (hence fewer measurements) to perform classification. Based on turfgrass morphology, two and three-variable functions were identified that correctly classified an estimated 75.4% of the cases into their true water use groups. A 75.4% correct classification was the best achieved and was as good as that obtained with all 14 original variables in the analysis simultaneously. Leaf angle, a component of canopy resistance, was the most important discriminator of water use group, predicting actual group membership in 72.1% of the cases. Correct classification was improved only slightly over leaf angle alone by incorporating a single leaf area component such as leaf width or leaf extension rate. These results show that discriminant analysis may be an efficient and useful tool for predicting the water use patterns of new cultivars on the basis of a few plant measurements that are routinely assessed by breeders.
Carbon isotope discrimination (Δ) is negatively correlated with water use efficiency (WUE) in several C3 grass species and was proposed as a selection criterion for improving WUE. Our objectives were to determine the relationship between Δ and WUE in cultivars of Kentucky bluegrass (Poa pratensis L., KBG) maintained as turf, and to determine the relationship between cultivar Δ and evapotranspiration (ET) rate measured under non-limiting soil moisture conditions. We view Δ as a potential index of ET and an alternative to weighing lysimeters in selecting C3 turfgrass for reduced ET. WUE of 11 cultivars was evaluated in 25-cm-diam., fritted clay filled lysimeters, over two 4-d harvest periods. Clipping dry weight accumulated above a 50-inm base mowing height for each 4-d period was used as the productivity component in calculating WUE. Gravimetric water loss determined by the water balanced method was used as the transpirational component. Cultivars differed significantly (P ≤ 0.05) in WUE, Δ, and ET, depending on the harvest period. Also, the reliability of Δ in predicting WUE and ET was dependent on the harvest period. During the first harvest period, Δ was inversely related with WUE (r = −0.55**, significant at P ≤ 0.01) and cultivar ET varied significantly with Δ (r = 0.64*, significant at P ≤ 0.05). During the second harvest period, no significant relationship (P > 0.05) developed between Δ and WUE (r = −0.21), or between Δ and cultivar ET (r = 0.32). Observations for the first and second harvest periods varied considerably in canopy temperature, with temperature ranging from 20.5 to 22.0 ± 1.3°C, and 27.3 to 36.0 ± 3.4°C, respectively. Theory predicts under the assumption of equal leaf temperature, Δ and WUE are correlated. It was likely that leaf temperature differences during the second harvest contributed significantly to the breakdown of the relationship between Δ and WUE. This assumption was likely met during the first harvest period only, therefore Δ and WUE (and ET) were related. Selecting for low Δ appears to have potential for identifying cool season turfgrass for reduced ET. However, further research is needed to determine the reliability of Δ in predicting ET under non-limiting and water limiting conditions.
Poa annua L. is a turfgrass commonly found on golf course putting greens, as well as many other environments in temperate regions of the world. Although it can produce a very desirable putting surface, the species is usually considered a weed, in part because it is characterized by continuous flowering during the growing season. Flowering at the low mowing heights of a golf green, is detrimental to the putting quality of the green and the stress tolerance of the plants. However, many individuals of P. annua flower only in the spring. We conducted this inheritance study to investigate the genetic control of flowering pattern in four representative genotypes, then relate the information to the ecology of the species in golf course environment, and propose improvements for P. annua breeding. One annual and three perennial tetraploid P. annua genotypes were crossed in all combinations. F1, F2, and in most cases F3 populations were grown and observed in field or greenhouse conditions over 1 to 3 yr. Each plant was rated for flowering pattern during the growing season. A genetic model involving one locus and two alleles with continual flowering completely dominant to seasonal flowering is proposed for control of flowering pattern based on F2 populations exhibiting 3:1 ratios of continual to seasonal flowering pattern types. Three distinct F3 populations are produced from F2 progeny: all continual flowering, all seasonal flowering, and segregating 3:1 continual to seasonal, similar to the F2 generation. There may also be evidence of modifying loci and maternal effects in some populations. This simple inheritance may explain the high heritability of flowering traits and rapid evolution of plant types in golf course turfgrass. Qualitative inheritance also provides the opportunity for efficient selection of desirable seasonal flowering P. annua plants.
Paper No. 961210002 of Scientific J. Series of the Minnesota Exp. Stn. The research was funded in part by the United States Golf Association and the O.J. Noer Foundation.
Hybrid bermudagrass cultivars (Cynodon dactylon L. × C. transvaalensis Burtt-Davy) ditfer in their responses to N and K for growth, total nonstructural carbohydrate (TNC) concentration, and turf quality scores. This 1995 research was conducted in Florida to compare responses of two bermudagrass cultivars to N and K under long-day (>13 h) and short-day (<13 h) conditions in a glasshouse. Evaluations were made concerning shoot and root growth, TNC concentration, and quality scores of 'FloraDwarf' and 'Tifdwarf' bermudagrass during establishment in a coarse sand medium. Experimental design under each photoperiod was a randomized complete block with factorial treatments consisting of two cultivars, four rates of N, four rates of K, and four replications. Data were analyzed by fitting multiple regression equations starting with a second order polynomial model. Growth of FloraDwarf was highly responsive to photoperiod, in that decreased daylengths reduced growth. No growth differences were found in Tifdwarf due to daylength. Growth increased in response to N in both cultivars, while growth response to K varied by cultivar. Both cultivars accumulated higher levels of TNC under short day conditions, with higher levels in FloraDwarf. Nitrogen fertilization reduced TNC levels in FloraDwarf under short days and in Tifdwarf under long days, while K fertilization reduced TNC levels in Tifdwarf under short days. Quality scores in both cultivars increased in response to N under long days, and in response to both N and K under short days. Results of these studies indicated that growth, TNC accumulation, and quality differed due to cultivar, photoperiod, and rates of N and K.
Florida Agric. Exp. Stn. Journal No. R05977.
Plants grown under saline conditions can experience elevated matric and osmotic stress between irrigation events. Research was conducted to assess the physiological response of tall rescue (Festuca arundinacea Schreber 'Monarch') and common bermudagrass (Cynodon dactylon L. 'Numex Sahara') to varying combinations of soil matric (ΨM) and osmotic potentials (ΨII). Two line-source gradient experiments were conducted, using municipal water with an electrical conductivity (EC) of 1.1 dS−1 or saline a quifer water blended with municipal water (EC of 6.0 dS m−1). Turf temperature, leaf xylem water potential (ΨL), tissue osmolality (ΨII-TISS), yield, evapotranspiration (ETa), percent cover, turf color, and tissue ion concentrations were monitored during a 68-d drydown period during the summer of the second year of experimentation. The total soil water potential (ΨT) was highly linear with distance from the line source with no significant difference between fresh and saline treatments within each species (bermudagrass, Adjr2 = 0.867**; tall rescue, Adjr2 = 0.810"). Significantly lower soil osmotic potentials were recorded under the saline treatment, while lower soil matric potentials were recorded under the fresh treatment for both species. Turf temperature, yield, ETa, turf color, and canopy cover responded to ΨM and ΨII in an additive fashion. The ΨL, ΨII-TISS and tissue ion concentrations in bermudagrass and ΨII-TISS and tissue ion concentrations in tall rescue responded in a nonadditive fashion, however. Our results suggest that water with a salinity level of 6.0 dS m−1 could be used as a supplemental irrigation source for both tall fescue and bermudagrasisf irrigation practices were designed to minimize water deficit.
Thatch accumulation is a serious problem in densely grown turfgrass maintained under low mowing heights. Opinions differ concerning effectiveness of cultural and chemical controls of thatch. The objectives of these studies were to determine the effectiveness of mechanical and chemical treatments in controlling thatch and their influence on soil nutrient retention and pH in a creeping bentgrass (Agrostis palustris Huds.) green growing on a U.S. Golf Association (USGA) rootzone. Thatch control treatments were vertical mowing (VM 4 and 8×/yr), coring (core 4×/yr), wetting agent (Wet Ag 7×/ yr), extra K (4×/yr), lime (L 4×/yr) and various combinations, and interactions of these with topdressing (Tpd 3 and 6×/yr). Rootzone nutrients determined were Ca, K, and P and rootzone pH levels were determined. Thatch measurements were determined with a rapid surface sod compression instrument termed the Thatchmeter II. Treatments and measurements were conducted for 6 yr with results reported for the last 3 yr. Lowest non-significant levels of thatch resulted following VM 4× or 8×/yr and VM + coring. Tpd 3× or 6×/yr also effectively prevented thatch buildup. When combining mechanical and chemical methods with Tpd, lowest non-significant levels of thatch resulted following VM 4× or 8×/yr, VM + coring, and VM + L, all combined with Tpd 6×/yr. Extra K (VM + K + L, K + L, K) and Wet Ag resulted in increased thatch. Lime did not influence thatch depth. Loss of rootzone K was 94% and increased with mechanical and chemical treatments. Loss of rootzone P was 86% but extra K and L treatments reduced P loss, especially under pH 7.3 following L treatments. Loss of rootzone Ca was 56% but L and extra K treatments under pH 7.3 reduced this loss.
'Midiron' and 'U3' bermudagrass were exposed to conditions known to induce cold acclimation [e.g., 8/4°C (day/night) temperature, 10-h photoperiod, 250 μmol m−2 s−1 photosynthetic photon flux density (PPFD)]. Tissues (leaves, crowns, and roots) were harvested stored frozen until processed. Polar membrane ids were isolated by thin layer chromatography, and fatty acids (FA) were separated and quantified by gas chromatography. Different organs from the same plant responded differentially to low temperature. Crowns showed the most dramatic changes in total FA content and composition and were the focus of this study. Overall, greater than 95% of the total FA content was accounted for by four FA species: palmitic acid (16:0), stearic acid (18:0), linoleic acid (18:2), and linolenic (18:3). Midiron (relatively cold-tolerant) responded more rapidly to a greater extent than did U3 (relatively cold-sensitive) as illustrated by the nearly four-fold increase of unsaturated FA:saturated FA ratio for Midiron vs. U3, and by the significant difference between the double bond index of the two genotypes. These data suggest that specific desaturase enzymes (e.g., ω-3 and ω-6) are of fundamental importance in controlling membrane lipid/fatty acid composition in response to low temperature and ultimately in avoiding the winter damage suffered by bermudagrass along its northern boundary of adaptation.
This research was supported by a grant from the USGA Green Section Research. This article is technical contribution number 4180 of the South Carolina Agric. Exp. Stn., Clemson Univ.
Bahiagrass (Paspalum notatum Fluegge) is a widely used grass for low maintenance turf areas such as highway rights-of-ways in the southeastern USA. Although well adapted to poor soils, low fertility, and low rainfall conditions, bahiagrass requires frequent mowing to maintain turf uniformity because of rapid and prolific seedhead production. This study was conducted in June and August of both 1995 and 1996 to determine the effects of various mowing timings either before or after application of the plant growth regulator AC 263,222 [(AC) (±)-2- [4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-lH-imidazol- 2-yl]-5-methyl-3-pyridinecarboxylic acid]. Unimproved bahiagrass turf was clipped to a 7.5-cm height at times corresponding with the following mowing treatments: mow 3 or 7 d before treatment (DBT) with AC 263,222 (0.07 kg ha−1 for all treatments), 1 h before treatment (HBT), 1 after treatment (HAT), 3 or 7 d after treatment (DAT), and control that had been mowed 2 wk earlier. Evaluations of bahiagrass color, seedhead count and height, and vegetative canopy height were made biweekly through 6 wk after AC treatment. Mowing at 3 or 7 DBT with AC resulted in color ratings that were always equal to or above the minimal acceptable rating and also provided at least 90% seedhead suppression through 6 WATin all trials. Mowing bahiagrass at 3 or 7 DAT consistently resulted in color ratings less than the minimal acceptable rating of 5 through 2 WAT, but bahiagrass growth regulation was excellent through 6 WAT in all trials. The mowing treatments of 1 HBT or 1 HAT both resulted in excellent growth regulation characteristics, but color ratings for turf mowed 1 HAT were consistently higher than those for plots mowed 1 HBT. These data indicate acceptable color and plant growth regulation can be obtained by timing mowing events at least 1 h before or after spraying AC 263,222 in low maintenance bahiagrass turf.
Contribution from the Mississippi Agric. For. Exp. Stn. Journal Series no. J-9139.
Infection of tall rescue (Festuca arundinacea Schreb.) with the mutualistic fungal endophyte Neotyphodium coenophialum (Morgan- Jones & Gams) Glenn, Bacon & Hanlin results in numerous biochemical and physiological changes that increase host persistence. This study was conducted to determine effects of steer (Bos taurus L.) grazing on changes in endophyte infestation levels of tall rescue pastures. Eighteen 1.2-ha pastures were seeded in 1992 in 20-cm drill rows involving combinations of high, medium, or low grazing pressure and 'Ky 31' tall fescue infested with N. coenophialum at four levels ranging from endophyte-free (E−) to 80% infestation (E+). Pastures grazed for about 10 mo. each year from fall 1993 until summer 996, although animals on some of the high grazing pressure pastures occasionally had to be removed because of insufficient forage. Endophyte levels were monitored yearly with protein-A sandwich enzyme-linked immunosorbent assay (PAS-ELISA). Stand density of tall fescue remained satisfactory throughout the study. After 2 yr, endophyte infestation levels in low grazing pressure pastures were at the same level as at the beginning of the study, and E+ levels remained constant in all pastures that started at high E+, regardless of grazing pressure. However, in high and medium grazing pressure pastures, E+ levels increased by 20 to 30%. Based on these data, we conclude that moderate and high grazing pressures influence endophyte infestation level of pastures and must be taken into account when designing pasture management systems.
The nutritive value of forage maize (Zea mays L.) may be improved through genetic selection for increased rate of fiber digestion or decreased indigestible fiber concentration. To identify sources of genetic variation, 45 maize inbreds were evaluated for in vitro neutral detergent fiber (NDF) digestion kinetic parameters using stem internode tissue harvested at silking during 2 yr. Near infrared reflectance spectroscopy (NIRS) was also used to estimate NDF digestion kinetic parameters. Maize inbreds varied significantly in NDF concentration and digestion kinetic parameters using either conventional in vitro analysis or NIRS predictions. Using NIRS predictions, inbreds varied in NDF concentration from 497 to 662 g kg−1 dry matter (DM), rate of NDF digestion ranged from 0.037 to 0.077 h−1, and extent of NDF digestion was 525 to 735 g kg−1 NDF. The ranges for NIRS predicted parameters were less than those observed for the calibration data set by conventional analysis. Correspondence between conventional analysis data and NIRS predictions were good, except for lag time. Digestion kinetics calculated from NIRS predicted residues provided more precise predictions of lag time and fractional rate of digestion when compared with observations derived from conventional analyses, than did direct prediction of these kinetic parameters. Correlations between rate of NDF digestion and 18-h NDF digestibility (r = 0.79) or between potential extent of NDF digestion and 96-h NDF digestibility (r = 0.95) were large enough that these two fermentation intervals might substitute for conducting complete digestion kinetic studies with eight to 10 fermentation times. The substantial genetic variation among these maize inbreds shows good potential for development of silage hybrids with improved fiber digestion parameters. Year and year × genotype interactions were significant suggesting that identification of superior inbred lines will require evaluations in multiple environments.
Mention of a proprietary product does not constitute a recommendation or warranty of the product by the University of Minnesota, Iowa State University, or the United States Department of Agriculture, and does not imply approval to the exclusion of other suitable products.
The triploid genome of plantain (Musa spp., AA group) has been considered intractable to genetic improvement because of the production of putatively homogeneous 2n (= 3x) gametes. Plantain breeding schemes have been based on the hybridization of 2n megaspores from the triploid plantain and haploid microspores from a wild diploid banana. The resultant fuli-sib populations of tetraploid hybrids exhibited extreme variation in phenotypic characteristics. This study was conducted to analyze the genetic constitution of tetraploid hybrids in order to characterize the nature of the gametes from which they were derived. Parental genotypes were screened with 31 primer pairs specific to different Musa microsatellite loci. Primers which detected polymorphisms between the parental genotypes were used to screen a population of 14 full-sib tetraploid hybrids. A subset of primers was also used to screen a population generated by self-pollination of the parental diploid banana. During analysis of the tetraploid hybrid population, 75% of the alleles donated by the maternal genotype (Obino l'Ewai) were observed to segregate. These data demonstrate the occurrence of recombination during the formation of 2n megaspores in triploid plantain. Analysis of the paternal diploid banana accession (Calcutta 4) and its selfed progeny suggests that this accession is highly heterozygous. These data demonstrate the importance of genetic characterization to Musa breeding, and also indicate that microsatellite markers are well suited for marker-assisted selection systems in Musa.
An important, but often limiting step in marker-assisted breeding is the efficient isolation of plant DNA for polymerase chain reaction (PCR) amplification. While there are many protocols for plant DNA isolation, they tend to be time consuming or difficult to use on many samples simultaneously. We have optimized an alternative approach to plant DNA isolation that immobilizes DNA on a solid matrix, followed by processing in a 96-well microtiter plate. A single person can isolate DNA and initiate PCR-based analyses for 96 individuals in one day. The DNA samples are suitable for several PCR-based procedures, including random amplified polymorphic DNA (RAPD), microsatellite (simple sequence repeats), and amplified fragment length polymorphism (AFLP) analyses. Because the DNA is immobilized on a solid matrix and processed in 96-well plates, this protocol could be modified for robotic manipulation.
Contribution of the Minnesota Agric. Exp. Stn J. series no. 22,613 on research conducted under Project 015, supported by G.A.R. funds. This research was also supported, in part, by USDA-NRI grant 95-37300-1593, Minnesota Soybean Research and Promotion Council Grant 13-95 and 19-96C, and a grant from the Minnesota Crop Improvement Association.
Tall fescue (Festuca arundinacea Schreb., 2n =6x =42) is a major cool-season pasture and turf grass with the genome constitution PPG1G1G2G2. Lack of aneuploid stocks hinders genetic studies in this important grass. The objective of this study was to characterize 23 fertile, embryo culture-derived, 'Kenwell' tall fescue monosomic lines by means of (i) RFLP markers, (ii) double monosomic analysis, and (iii) isozyme phenotypes of F1 progeny. Standard procedures were used for RFLP chemiluminescent detection, crossing, cytogenetic analyses, and obtaining isozyme banding patterns. Using RFLP markers, we ascertained that four monosomic lines were hemizygous for a P-genome marker and the 23 plants were placed into 17 groups based on plants having the same RFLP banding patterns. For double monosomic analysis, metaphase I chromosome pairing relationships were ascertained for 220 F1 progeny from 26 crosses among the monosomic lines. Five of the progeny were trisomic, 148 disomic, 60 monosomic, and seven had 40 chromosomes. All of the 40-chromosome progeny were double monosomic plants, indicating the monosome carried in the parents were not the same chromosome. Isozyme phenotypes were ascertained for 203 F1 progeny from crosses for double monosomic analysis which had both 42- and 41-chromosome progeny to determine if an isozyme locus mapped to the monosome from the female parent. A PGI-2 locus most likely mapped to one monosome. Double monosomic analysis provided evidence that at least four of the 21 possible tall fescue monosomic lines were obtained.
Mention of a trademark, vendor, or proprietary product does not constitute a guarantee or warranty of the product by the USDA or the Univ. of Kentucky and does not imply its approval to the exclusion of other products that may also be suitable. Contribution as Journal Paper No. 96-06-192 of the Kentucky Agric. Exp. Stn.
Mature embryos of oat (Avena sativa L.) have been used to establish regenerable tissue cultures with potential use for transformation. The objective of this study was to investigate tissue cultures established from mature embryos of oat as an alternative source of totipotent target cells for microprojectile bombardment-mediated transformation. Mature embryos of a specific genotype, GAF/Park-1, were incubated on a tissue culture induction medium for 1, 4, 8, or 9 wk before either being directly bombarded after 1 and 4 wk, or bombarded as tissue cultures initiated after 8 and 9 wk incubation. The 8- and 9- wk-old tissue cultures yielded the greatest numbers of transgenic tissue cultures (3.2 transgenic tissue cultures per microprojectile bombardment treatment). Three additional transformation experiments were conducted with mature embryo-derived 8- to 9-wk-old tissue cultures to determine the regeneration capacity and production of fertile transgenic plants. Overall, fertile plants were regenerated from 35 of 85 independently derived transgenic tissue cultures. Identification of mature embryo-derived tissue cultures as a source of transformable totipotent cells should reduce the expense and labor involved in oat transformation. Moreover, the uniformity and convenience of this explant likely will stimulate further investigations in oat transformation efficiency.
Minnesota Agric. Exp. Stn Publ. No. 97113-0006
Karnal bunt (Tilletia indica Mitra) infestation of wheat (Triticum aestivum L.) kernels reduces grain quality. Deployment of genetic resistance would be preferable to chemical applications for control of the disease. Inoculation studies were carried out in a wheat mapping population with the aim of locating genes for resistance. Recombinant inbred (RI) lines from a cross between a resistant synthetic wheat (Triticum turgidum 'Altar 84' & T. tauschii) and the susceptible common wheat cultivar 'Opata 85' were inoculated with Karnal bunt sporidial suspension and evaluated for symptom development in the field for three seasons and in the greenhouse. Based on restriction fragment length polymorphism (RFLP) analyses, regions on chromosome arms 3BS and SAL carrying marker alleles from the Altar durum parent were consistently associated with reduced kernel disease. Main marker effects accounted for up to 32% of disease variation in the field but only 15% in the greenhouse, where the level of disease was higher, suggesting an environmental component of resistance. The tagging of these Karnal bunt partial-resistance genes in tetraploid and hexaploid backgrounds may facilitate the accumulation of resistance via marker-assisted transfer to susceptible durum and common wheat cultivars. This practice should reduce laborious disease screening requirements.
Forty-three landrace (LR) barley (Hordeum vulgare) populations from a wide agro-ecological range in Ethiopia were assayed for RFLPs with 31 probes distributed over all barley chromosomes. Diversity between LRs was analyzed by Nei's genetic similarity (F) and genetic distance (d) parameters. The 43 populations were represented either by one single line (Set 1) or by four to five lines in a subset of populations(Set 2). The greatest diversity between LRs was observed in Set 1. However, many populations appeared rather similar in RFLP patterns. Relationships between LRs were sharply altered by including the within LR-diversity component (Set 2), and the average level between-LR differentiation was reduced compared with Set 1. The within-LR diversity was similar in magnitude to that for geographical regions. Levels of within-LRR FLP diversity were poorly correlated with morphological and isozyme variations in the same LR or region. The results highlight the critical role of a sampling strategy that includes both within and between LR components, which is important both to large scale and core collections.
Selection of parents is an important first step in any breeding program. The ability to assess accurately genetic differences between parents and subsequently to predict progeny performance would enhance the efficiency of breeding programs. This study examined the association between genetic similarity (GS) based on coefficient of parentage (COP) and molecular marker data for 10 hard red spring wheats (Triticum aestivum L.). In addition, we assessed the value of parental diversity based on COP, and molecular marker data, and combinations of them, to predict progeny genetic variance for 12 crosses of hard red spring wheat. Coefficient of parentage was computed for all pair-wise combinations of the 10 parents. Parents were assayed with 205 sequence-tagged sites (STS) polymerase chain reaction (PCR) primer sets and 14 arbitrarily chosen selective amplified fragment length polymorphism (AFLP) primer combinations. Fifty random progeny lines from each of 12 crosses among the 10 parents were grown in three field environments. Genetic variance estimates were obtained for nine traits, and an overall variance was obtained as the sum of single trait variance components from standardized data. Genetic similarities estimated from COP, STS-PCR primer sets, and AFLP primer combinations were interrelated. Genetic distance computed from COP, STS-PCR primer sets, AFLP primer combinations, or combinations of them was not a strong predictor of progeny genetic variance or number of transgressive segregates for single traits. However, significant correlations were obtained between COP and STS-PCR-based genetic distance and overall variance.
Contribution no. J-5115 Montana Agric. Exp. Stn.
The genotype and the environment in which donor plants grow influence embryogenic competence of immature wheat (Tritium Estevan L.) embryos and levels of endogenous hormones in kernels. We studied relationships between embryonic competence and hormone levels in kernels and Calli of PC YT 10 (highly competent) and Yaqui 50 (nearly incompetent) wheat grown at 15 and 25°C. Endogenous levels of abscissa acid (ABA), in dole-3-acetic acid (AA), and stockings were determined for kernels at 0, 4, 8, and 12 d past an thesis (DOPA). Immature embryos were cultured at 12 DOPA and hormone content of Calli was determined at 7, 14, 21, and 28 d past culture initiation (DP|). Somatic embryos were counted at 28 DIP. Embryonic competence was associated with low AA and ABA levels in kernels from 0 to 12 DOPA, high seating to AA ratios in kernels at 4 DOPA, and high stoking to auxin ratios in Calli. Incompetence in Yaqui 50 may be due to low stoking to auxin ratios in kernels at 4 DOPA and sharp increases in kernel AA and/or ABA levels prior to embryo excision (12 DOPA). Low temperatures during donor plant growth delayed the rise in AA and ABA in Yaqui 50 kernels and significantly increased the embryogenic response from both Yaqui 50 and PCYT 10 embryos. It may be possible to increase competence of nearly nonembryogenic wheat lines by growing donor plants in cool conditions, which appear to delay the accumulation of IAA and ABA in kernels.
This research was supported by USDA NRI-CGP award no. 91-37300-6457, a centers of excellence grant from the State of Utah, and by the Utah Agric. Exp. Stn., Logan, UT 84322-4810. Approved as Utah Agric. Exp. Stn., journal paper no. 5036.
Nutrient solution systems have been considered an alternative method to field evaluations for studies of iron deficiency chlorosis (IDC) and for breeding soybeans [Glycine max (L.) Merr.] with improved iron efficiency. Although rates of gain are similar for both methods, it has not been previously demonstrated that field tests and nutrient solution tests for IDC measure similar genetic mechanisms. To test this, quantitative trait loci (QTL) identified in nutrient solutions were compared with those previously identified in field studies. F2:4 lines from two populations, Pride B216 × A15 and Anoka × A7, were grown in nutrient solution and evaluated for IDC by visual scores and determinations of chlorophyll concentrations. In the Anoka × A7 population, one major gene on linkage group N, and modifying QTL on linkage groups A1 and I, that were previously mapped during field tests, also were identified in the nutrient solution test. In the Pride B216 × A15 population, one QTL previously mapped on Linkage Group I during field tests was not identified in the nutrient solution test, and a newly identified QTL was mapped on Linkage Group BI. QTL on Linkage Groups B2, G, and N were identified in both field and nutrient solution tests. We concluded that similar QTL are identified in nutrient solution and field tests and, therefore, both systems identify similar genetic mechanisms of iron uptake and/or utilization.
Contribution of the North Central Region, USDA-ARS, projects No. 3236 and 3107 of the Iowa Agriculture and Home Economic Exp. Stn, Ames, IA 50011. Journal paper No. J-17337.
The peanut root-knot nematode [Meloidogyne arenaria (Neai) Chitwood race 1] causes significant economic losses throughout the peanut (Arachis hypogaea L.) production areas of the southern USA. No resistant peanut cultivars are available; however, a breeding line (UF81206) has been observed to be less sensitive to M. arenaria than commercial cultivars. The objectives of this study were to evaluate the sensitivity to M. arenaria of UF81206 and related breeding lines and to determine if these responses are due to tolerance, or resistance. The yield of 10 peanut genotypes was evaluated for 2 yr in a field with high M. arenaria population densities and in a field with little or no M. arenaria. Two greenhouse tests were conducted to measure nematode reproduction. The breeding lines UF81206-Q4, UF81206, and UF93111 yielded similarly to Florunner when grown in fields with no nematodes and significantly higher than Florunner when grown in fields with high nematode population densities. These genotypes also supported less nematodere production in greenhouse trials, indicating that these genotypes have a moderate level of resistance. P1203396is in the pedigree of these breeding lines and also exhibited a moderate level of resistance in a greenhouse trial.
Crimson clover (Trifolium incarnatum L.) is a cool-season annual forage legume. Few morphological traits are recorded to distinguish genotypes and very little is known about its genetic diversity. The objective of this research was to classify and characterize the genetic diversity in the USDA-ARS National Plant Germplasm System (NPGS) accessions and USA and European Economic Community (EEC) cultivars. Descriptions of EEC cultivars and their breeding histories are also presented. A secondary objective was to determine if T. incarnatum vat. molinerii (Baib. ex Hornem.) Ser. should be considered a distinct species. Genomic DNA from leaves of 37 taxa was examined in 1993 by the polymerase chain reaction (PCR) using 29 random amplified polymorphic DNA (RAPD) markers. Plants grown in the greenhouse were also observed for inflorescence color and relative flowering time. Cluster analysis of pairwise means of RAPD maker distances and cultivar pedigree histories revealed similar genetic backgrounds among most cultivars. Flower color was associated with RAPD marker grouping (P ≤ 0.02) but flowering time was not (P ≤ 0.31). Bolh red vs. non-red inflorescence color and early- vs. late-flowering traits could be predicted by specific RAPD bands (95 and 93% accuracy, respectively). Analysis of internal transcribed spacer region sequences (ITS) from ribosomal DNA (rDNA) showed diverse crimson clover taxon to be more similar to one another than to var. molinerii (0.4 and 0.9% base pair differences, respectively; P ≤ 0.001). Because of the limited diversity within the current NPGS collection, additional accessions should be collected, morphologically evaluated, and genetically analyzed to broaden the genetic base of the collection. Crimson clover var. molinerii is a sister taxa of more typical crimson clover accessions but exhibits enough ITS diversity to be classified as another species.
Obtaining accurate seed yield information from soybean[Glycine max (L.) Merr.] field research environments and concurrently conserving valuable field space is desirable. The purpose of this study was to determine the effect of plot length and alley width on the response of short- and tall-statured Maturity Group(MG) V soybean cultivars to end-trimming after maturity. Experiments were conducted in 1995 and 1996 at the Delta Research and Extension Center at Stoneville, MS, (lat.33°26′). 'Hutcheson' (relatively shorts stature) and 'DP3 3589' in 1995 and 'DP 3588' in 1996 (both relatively tall stature) were planted on 9 May 1995 and 15 May 1996 Treatments were plot length (6.10 or 15.25m ), alley width (0.90 or 2.45m ), and end-trim length (0, 0.45, or 0.90m ). Average height of Hutcheson at maturity was 52 cm in 1995 and 55 cm in 1996, while average height of DP 3589 in 1995 and DP 3588 in 1996 was 88 cm. All cultivars responded similarly in yield to all factors in this experiment. End-trim length was the only factor that significantly affected average yields. Not end-trimming resulted in an average yields of 2573k g ha−1, while end-trimming either 0.45 or 0.90 m resulted in average yields that were nearly identical (2356 and 2 337k g ha−1, respectively). Contrary to our hypothesis, increasing plot length from 6.10 to 15.25m and decreasing alley width from 2.45 to 0.90 m did not negate the end-of-plot effect on yield of soybean grown in nonirrigated field plots. These results indicate that soybean grown in plots with row lengths and alley widths that are within the confines of the dimensions used in our experiment should be end-trimmed to eliminate end-of-plot effects. Also, field space can be conserved by using the 6.1-m plot length and the 0.90-m alley width.
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Applause Please Trailer (1975)
01 January 1975 20 mins
This film makes a personal statement on TV and commercial advertising and their insidious effect on the susceptibility of people. The message is given using an avant-garde style, told in mime and dramatics. Cast includes Max Gillies, Joe Bolza and Bob Thorneycroft and original music performed by Frank Zappa.
Watch the official Applause Please 1975 trailer in HD below or find more Applause Please videos on Vidimovie.