Title of Invention: DOWNY MILDEW RESISTANT CUCUMBER PLANTS Abstract: The present invention relates to cucumber lines having increased resistance to Downy Mildew. The present invention also relates to parts of cucumber plants from lines having increased Downy Mildew resistance, including seeds capable of growing cucumber plants with increased Downy Mildew resistance. Further provided are methods of producing such plants by genetic marker assisted selection. Detailed Description: CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application Ser. No. 61/045,551, filed Apr. 16, 2008, the entire disclosure of which is incorporated herein by reference. FIELD OF THE INVENTION The invention relates to cucumber plants having Downy Mildew resistance and methods for producing such plants. BACKGROUND OF THE INVENTION Cucumber (Cucumis sativus L.) is a popular vegetable crop that has been cultivated for several thousand years and is grown worldwide. Cucumber plants are grown in a wide range of climates, and in open fields as well as greenhouses. The two main types of cucumber fruit grown commercially today are fresh market (slicing) and processing (pickling). Downy Mildew (DM) is caused by the fungus Pseudoperonospora cubensis (P.c.), which causes significant crop losses among many Cucurbit species, including cucumber. The disease is found worldwide and favors moist, temperate conditions. The disease affects greenhouse grown plants, and plants grown in the field. DM is one of the most important foliar diseases of cucurbits, and can reduce fruit yield and quality, and may kill susceptible seedlings. Symptoms of DM infection are variable. Initial symptoms include sharp, irregular yellow lesions on the upper surface of the leaves, which eventually become more distinct on both sides of the leaves. The underside of the leaves may exhibit a whitish-gray, brown, or light blue growth, particularly under moist conditions. This downy growth is spores produced on the lower surface of the lesion. A general yellowing of affected leaves typically occurs as the lesions coalesce into one large lesion, eventually causing the leaf to wilt and die. The disease can progress quite rapidly, killing foliage in a matter of a few days and resulting in poor fruit production and quality. Cucumber fruit are not affected directly, but major defoliation exposes the fruit to sunscald. Once it appears on a crop, DM rapidly spreads by wind, or splashing rain and/or irrigation water. Disease management and prevention requires destruction of all plants from infected nurseries and disinfection of the facilities. Emergence of a new isolate of DM has also overcome some previously known resistant lines. Thus, there is a need for new cucumber varieties having resistance to DM. SUMMARY OF THE INVENTION In one aspect, the invention provides a method of producing a cucumber plant having resistance to Downy Mildew comprising the steps of (a) crossing a cucumber plant of accession PI197088 with a second cucumber plant having at least one desired trait; and (b) selecting at least a first progeny cucumber plant resulting from the crossing that comprises resistance to Downy Mildew and the desired trait. In one embodiment, a method is provided wherein the desired trait is selected from the group consisting of: fruit size, shape, color, surface appearance; seed number, seed size, locule number; pericarp thickness and toughness; taste, bitterness, the presence of tubercles, shelf life, plant vigor, leaf shape, leaf length, leaf color, plant height, whether the plant is determinate or not, time to maturity, adaptation to field growth, adaptation to greenhouse growth, fruit quality acceptable to market, and resistance to one or more diseases or disease causing organisms selected from the group consisting of Verticillium wilt, root knot nematodes, Tobacco Mosaic Virus, Cucumber scab, Powdery mildew, Target spot, Cucumber Mosaic Virus, Fusarium wilt, Papaya Ringspot Virus, and Zucchini Yellow Mosaic Virus. In specific embodiments, selecting the first progeny comprises identifying the presence of at least a first genetic marker in the first progeny that is genetically linked to a locus contributing to Downy Mildew resistance. In another embodiment, selecting the first progeny further comprises selecting the progeny based on the presence of a plurality of genetic markers from the second cucumber plant present in the progeny. In yet other embodiments, the genetic marker is selected from the group consisting of markers CAPs—21826, CAPs_ENK60, CAPs_ENK59, CAPs—17170, CAPs—17179, CAPs—18229, CAPs—17563/66, and CAPs_ENK70. In certain embodiments, the genetic marker is selected from the group consisting of CAPs_ENK60, CAPs—17170, and CAPs—17563/66. In a further embodiment, the method further comprises the step of: (c) crossing the progeny plant with itself or a third plant to produce a progeny plant of a subsequent generation. In another embodiment, the method further comprises the steps of: (d) crossing the progeny plant of a subsequent generation with itself or a second plant; and (e) repeating steps (c) and (d) for an additional 3-10 generations to produce an inbred cucumber plant derived from the cucumber accession PI197088. In one embodiment, the method may be defined as one wherein said progeny plant of a subsequent generation is selected for crossing based on the presence of resistance to Downy Mildew and the desired trait. In certain embodiments the progeny plant of a subsequent generation is selected at each generation for crossing based on the presence of the resistance to Downy Mildew and desired trait. In other embodiments, the method may be defined as one wherein selecting the progeny plant of a subsequent generation comprises identifying the presence of at least a first genetic marker in the first progeny that is genetically linked to a locus contributing to Downy Mildew resistance. In particular embodiments, selecting the progeny plant of a subsequent generation further comprises selecting the progeny based on the presence of a plurality of genetic markers from the second cucumber plant present in the progeny. In other embodiments, step (e) is repeated a sufficient number of generations to obtain an inbred cucumber plant that comprises the resistance to Downy Mildew and otherwise comprises the agronomic traits of the second cucumber plant. In another aspect, the invention provides a plant produced by the method wherein step (e) is repeated a sufficient number of generations to obtain an inbred cucumber plant that comprises the resistance to Downy Mildew and otherwise comprises the agronomic traits of the second cucumber plant In yet another aspect, a seed is provided of a cucumber line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1; representative samples of seed of said lines having been deposited under ATCC Accession Number PTA-9375, ATCC Accession Number PTA-8930, ATCC Accession Number PTA-8931, ATCC Accession Number PTA-8953, ATCC Accession Number PTA-8954, ATCC Accession Number ______, ATCC Accession Number ______, and ATCC Accession Number ______, respectively. In still yet another aspect, the invention provides a plant grown from seed of a cucumber line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1. The invention also provides a plant part of such a plant. In certain embodiments the plant part is selected from the group consisting of a leaf, fruit, pollen, an ovule and a cell. In still yet another aspect, the invention provides a cucumber plant, or a part thereof, having all the physiological and morphological characteristics of the cucumber plant selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL 1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1. Another aspect of the invention provides a tissue culture of regenerable cells of a cucumber line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1. In certain embodiments, the tissue culture comprises cells or protoplasts from a plant part selected from the group consisting of embryos, meristems, cotyledons, pollen, leaves, anthers, roots, root tips, pistil, flower, seed and stalks. The invention also provides a cucumber plant regenerated from the tissue, wherein the regenerated plant expresses all of the physiological and morphological characteristics of a plant selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1. In another aspect, the invention provides a method of producing cucumber seed, comprising crossing the plant selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1, with itself or a second cucumber plant. In one embodiment, the seed is an F1 hybrid seed. In another aspect, the invention provides an F1 hybrid plant produced by growing the seed. In yet another aspect, the invention provides a method for producing a seed of a line ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, or 03/8039-5_TUP03_DMFL—1 cucumber plant comprising the steps of: (a) crossing a cucumber plant of a line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1, with a second cucumber plant; and (b) allowing seed of a line ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, or 03/8039-5_TUP03_DMFL—1-derived cucumber plant to form. In a further aspect, the invention provides a method of vegetatively propagating a line ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, or 03/8039-5_TUP03_DMFL—1 cucumber plant, comprising the steps of: (a) collecting tissue capable of being propagated from a plant of claim 16; (b) cultivating said tissue to obtain proliferated shoots; and (c) rooting said proliferated shoots to obtain rooted plantlets. In a certain embodiment, the method further comprises growing plants from said rooted plantlets. In yet another embodiment is provided a method of introducing a desired trait into a cucumber line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1, comprising: (a) crossing a plant of a line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1, with a second cucumber plant that comprises a desired trait to produce F1 progeny; (b) selecting an F1 progeny that comprises the desired trait; (c) crossing the selected F1 progeny with a plant of a line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1, to produce backcross progeny; (d) selecting backcross progeny comprising the desired trait and the physiological and morphological characteristic of a cucumber line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1; and (e) repeating steps (c) and (d) three or more times in succession to produce selected fourth or higher backcross progeny that comprise the desired trait. Another embodiment of the invention is a cucumber plant produced by such a method. Another aspect of the invention relates to a method of producing a plant of a cucumber line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1, comprising an added desired trait, the method comprising introducing a transgene conferring the desired trait into a plant of cucumber a line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1. Yet another aspect of the invention provides a plant of a cucumber line that exhibits one or more traits selected from the group consisting of: resistance to Angular leaf spot, Anthracnose race 1, Cucumber Scab, Downy mildew, Powdery Mildew, Papaya Ringspot, Zucchini Yellow Mosaic, Cucumber Mosaic Virus, and fruit quality acceptable to market, wherein the combination of traits is controlled by genetic means for the expression of such one or more traits found in a cucumber line selected from the group consisting of: ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1. A seed of a plant produced by such a method is another embodiment of the invention. The invention also provides, in another aspect, a method of determining the genotype of a cucumber plant of a line selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1, comprising obtaining a sample of nucleic acids from said plant and detecting in said nucleic acids a plurality of polymorphisms. In particular embodiments, the method further comprises the step of storing the results of the step of detecting the plurality of polymorphisms on a computer readable medium. Thus, a computer readable medium produced by obtaining a sample of nucleic acids from said plant, detecting in said nucleic acids a plurality of polymorphisms, and storing the results of the step of detecting the plurality of polymorphisms on a computer readable medium is another aspect of the invention. In yet another aspect, the invention provides a method of producing cucumbers comprising: (a) obtaining a plant of the current invention, wherein the plant has been cultivated to maturity; and (b) collecting cucumbers from the plant. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a genetic map (left) and LOD plot (right) for marker effects on Downy Mildew reaction in 148 F3 families from the cucumber L088 (Lucinde×PI197088) population. Lines between the genetic map and LOD plot provide reference positions for three of the markers to aid in comparisons of map position and LOD score. FIG. 2 depicts Downy Mildew resistance data for certain additional markers in an identified Downy Mildew resistance contributing QTL region, showing correlation between DM resistance and marker position. DETAILED DESCRIPTION OF THE INVENTION The invention provides cucumber plants and in particular cucumber (Cucumis sativus) lines having resistance to Downy Mildew (DM). Such cucumber lines can be referred to as DM resistant cucumber varieties. Methods of producing DM resistant cucumber lines are also provided. Also disclosed herein are molecular markers that are linked to quantitative trait loci contributing to DM resistance, and F1 hybrids of the DM resistant cucumber plants. Through use of the markers, one of skill in the art may increase the degree of DM resistance in cucumber or select plants for an increased predisposition for DM resistance. The QTLs identified in this manner may be combined with one or more other QTLs that also contribute to DM resistance, as desired. The DM resistant cucumber plants of the present invention may bear one or more alleles conferring DM resistance that have been introduced into the cucumbers from a line designated PI197088 comprising the DM resistance, but otherwise comprising poor agronomic characteristics. The resulting DM resistant cucumber plants of the present invention surprisingly display elite agronomic traits in combination with DM resistance, while lacking deleterious traits. DM resistant cucumber plants may have large leaves that form a canopy over the fruit. The vine is typically indeterminate and grown on trellises or the ground. DM resistant cucumber plants may have dark green, green, light green to yellow, and occasionally yellow to brown leaves. The leaves of the DM resistant cucumber plants vary in size, but typically are from about 200-250 mm in length and 150-200 mm in width, and are usually simple, alternate, palmate, and lobed. The ripe fruit of DM resistant cucumber plants of the present invention can vary from light to medium green, or even dark green, and typically the color on an individual fruit varies from a lighter-colored blossom end to a darker colored stem-end. The color may be mottled with yellow speckles. The fruit of DM resistant cucumber is typically elongated and cylindrical with rounded or blunt ends, but may also be straight or curved, and is usually 25-30 cm in length at harvest maturity, although the fruit may be edible at 11-14 cm. The skin of the fruit is typically smooth, dull and thick; the skin may be tough or tender with a varied number of tubercules. The flesh of the fruit is usually cream colored, with or without stripes, and has a bitter-free taste. As used herein, a “susceptible control cucumber plant” refers to a cucumber plant susceptible to Downy Mildew (DM susceptible) including commercially available and wild relatives of modern cucumber plants. In one aspect, the control cucumber plant is the variety MARAM, SMR58, or SPRINT 440. A “resistant control cucumber plant” may also be utilized when evaluating DM resistant cucumber varieties. In one embodiment, such a control is a cucumber plant that is not susceptible to DM, but is otherwise agriculturally undesirable, for example, variety PI197088. Similarly, some controls may have intermediate resistance, for example, controls with intermediate resistance to DM may be DMP21, GP14, LLP-1, or POINSETT 76. As described herein, a control cucumber line is grown under similar environmental conditions as the comparative cucumber line, according to the present disclosure. As used herein, a “hybrid cucumber plant” includes a plant resulting directly or indirectly from crosses between populations, breeds or cultivars within the species Cucumis sativus. “Hybrid cucumber plant” as used herein also refers to plants resulting directly or indirectly from crosses between different varieties or genotypes. As used herein, a “female parent” refers to a cucumber plant that is the recipient of pollen from a male donor line, which pollen successfully pollinates an egg. A female parent can be any cucumber plant that is the recipient of pollen. Such female parents can be male sterile, for example, because of genic male sterility, cytoplasmic male sterility, or because they have been subject to manual emasculation of the stamens. Genic or cytoplasmic male sterility can be manifested in different manners, such as sterile pollen, malformed or stamenless flowers, positional sterility, and functional sterility. As used herein, “cytoplasmic male sterility” refers to plants that are not usually capable of breeding from self-pollination, but are capable of breeding from cross-pollination. As used herein, “linkage” is a phenomenon wherein alleles on the same chromosome tend to segregate together more often than expected by chance if their transmission was independent. As used herein, a “marker” is an indicator for the presence of at least one phenotype, genotype, or polymorphism. Markers include, but are not limited to, single nucleotide polymorphisms (SNPs), cleavable amplified polymorphic sequences (CAPS), amplified fragment length polymorphisms (AFLPs), restriction fragment length polymorphisms (RFLPs), simple sequence repeats (SSRs), insertion(s)/deletion(s) (INDEL(s)), inter-simple sequence repeats (ISSR), and random amplified polymorphic DNA (RAPD) sequences. A marker is preferably inherited in codominant fashion (both alleles at a locus in a diploid heterozygote are readily detectable), with no environmental variance component, i.e., heritability of 1. A “nucleic acid marker” as used herein means a nucleic acid molecule that is capable of being a marker for detecting a polymorphism, phenotype, or both associated with DM resistance. As used herein, a “desirable trait” or “desirable traits” that may be introduced into DM resistant cucumber plants by breeding may be directed to the cucumber fruit or the cucumber plant. Desirable traits to be introduced into cucumber plants and cucumber fruit may be independently selected. Desirable cucumber fruit traits that may be independently selected include, but are not limited to: fruit size, shape, color, surface appearance; seed number, seed size, locule number; pericarp thickness and toughness; taste, bitterness, the presence of tubercles, and shelf life. Desirable cucumber plant traits that may be independently selected include, but are not limited to; plant vigor, leaf shape, leaf length, leaf color, plant height, whether the plant is determinate or not, time to maturity, adaptation to field growth, adaptation to greenhouse growth, and resistance to one or more diseases or disease causing organisms such as Verticillium wilt, root knot nematodes, Tobacco Mosaic Virus, Cucumber scab, Anthracnose race 1, Powdery mildew (e.g. caused by Erysiphe cichoracearum or Sphaerotheca fuliginea), Target spot, Cucumber Mosaic Virus and Fusarium wilt. Any combination of desirable cucumber fruit traits, cucumber plant traits, or cucumber plant and fruit traits may be combined with a DM resistance trait. DM resistance of a cucumber plant provided herein can potentially be defined as complete resistance or partial resistance. The DM resistance of a cucumber plant provided herein can be measured by any means available in the art. In one aspect, DM resistance of a cucumber plant is determined using a disease rating of foliar chlorotic and/or necrotic lesion development after inoculation or infection with DM on cucumber leaves using a scale of symptoms of 0%, 10%, 20%, 30%, 40%, 50%, 60% and greater than about 60% lesion covering the leaf area. A disease rating of 0% indicates a completely resistant plant. In another aspect, DM resistance is determined by obtaining disease ratings of symptom development after one or more rounds of inoculation or infection with DM on cucumber leaves and/or cotyledons. Resistance in a leaf test may be scored on the scale: Index Value Symptoms 1 Absence of symptoms 2 Few small necrotic lesions without expansion 3 Few chlorotic and some necrotic lesions with limited expansion 4 Large expanding angular chlorosis with limited necrotic lesions 5 Large expanding angular chlorosis with expanding necrotic lesions Tests are evaluated once symptoms have developed on susceptible checks (e.g. cultivars Maram or SMR58). PI 197088 may be used as a “resistant” control; cv. Poinsett 76 may be used as a control to assess “intermediate” levels of resistance/susceptibility to P. cubensis. Three observations are made on each plot, one at each end and one in the middle. The mean disease index for each plot is calculated. These are averaged for all three replicates and the standard deviation is determined. The disease index ranges for the categories “Resistant,” “Intermediate Resistant” and “Susceptible” are then determined. Varieties are generally trialed several times before a final disease resistance level determination is made. Scores of 1-5 indicate varying levels of resistance or susceptibility. A score of 1-2 after one or more rounds of inoculation or infection, and preferably two or more rounds of infection, indicates a resistant plant. A score of 3 after one or more rounds of inoculation or infection, preferably two or more rounds of infection, indicates a plant exhibiting intermediate resistance. A score of 4-5 indicates a susceptible plant. Scores on this 1-5 scale would correlate to a 1-9 scale where 1=1, 2=3, 3=5, 4=7, and 5=9. In one aspect of the invention, a plant is assayed for DM resistance, partial resistance or susceptibility by image analysis of foliar tissue using about 3 leaves per plant captured in a digital image. The image analysis is conducted to determine the percentage of tissue damage and derive a disease rating. Image analysis software and methods used for quantifying visual differences in two or three dimensions are those set forth in Bright, 1987 (J. Microscopy 148:51-87) and Bickmore et al., 1999 (Geol. Mat. Res. 1(5):1-19). With respect to image analysis: “very resistant” exhibits between about 0% and 5% leaf area symptoms of chlorotic and/or necrotic lesions; “resistant” is between about 1% and 20% of the leaf area having symptoms of chlorotic and/or necrotic lesions; “substantially resistant” is between about 20% and 30% of the leaf area having symptoms of chlorotic and/or necrotic lesions; “mid-resistant” is between 40% and 50% of the leaf area having symptoms of chlorotic and/or necrotic lesions; “partially resistant” is less than or equal to about 50% of the leaf area having symptoms of chlorotic and/or necrotic lesions; “mid-susceptible” is between about 50% and 60% of the leaf area having symptoms of chlorotic and/or necrotic lesions; and “susceptible” is between about 60% and 100% of the leaf area having symptoms of chlorotic and/or necrotic lesions. A resistant plant can be characterized by other aspects as set forth herein, or by the use of other means, such as quantitative PCR to determine the level of infection. Cucumber lines having DM resistance, or partial resistance, demonstrate a reduced level of symptoms relative to a non-resistant control cucumber line after inoculation or infection with DM. The level of symptoms can be used as an indicator of DM resistance. Disease symptoms measured can be any disease symptoms associated with DM infection. Symptoms can be selected from the group consisting of leaf blisters, necrosis, soft fruits, mosaic, chlorotic veins, chlorotic leaf spots, chlorotic and/or light green mosaic on leaves, fruit lesions, or combinations thereof. In one aspect, a DM resistant cucumber line demonstrates a reduction of foliar symptoms of chlorotic and/or necrotic lesions of at least, or greater than, 10%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, or 98% relative to a non-resistant control cucumber line. In other aspects, the leaves of a DM resistant cucumber plant demonstrate less than 15%, or less than 10%, or less than 5%, or less than 2% symptomatic area when exposed to DM. In another aspect, the cucumber plant belongs to a cucumber variety or cultivar, and in another aspect, the cucumber plant is an inbred cucumber plant. In another aspect, the cucumber plants and varieties provided herein demonstrates little or no symptoms of chlorotic and/or necrotic lesions after inoculation or infection with DM. In some aspects, a DM resistant cucumber plant demonstrates symptoms of chlorotic and/or necrotic lesions on less than 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3% 2%, or 1% of the cucumber leaf surface. DM resistant cucumber plants may exhibit a delay in the onset of symptoms of chlorotic and/or necrotic lesions relative to a non-resistant control cucumber plant. In some embodiments, the DM resistant cucumber plants exhibit a delay of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or more days in the onset of symptoms of chlorotic and/or necrotic lesions relative to a control cucumber plant. In other embodiments, the DM resistant cucumber plants exhibit a delay of at least 7 or more days, 10 or more days, or 14 or more days in the onset of symptoms of chlorotic and/or necrotic lesions relative to a control cucumber plant. In one aspect, the cucumber plant is a seedling at the time of inoculation or infection. In some aspects, the cucumber plant is a seedling at the 4, 5, 6, 7, or 8 leaf stage of development when inoculated. In one aspect, disease symptoms can be measured at any time after pathogenic challenge of a cucumber plant. In other aspects, symptoms can be measured 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or more days after inoculation. In another aspect, the cucumber plant is any age of plant at the time of inoculation or infection. In another aspect, disease symptoms can be observed after DM challenge of an entire plant or a part thereof, for example, a plant cutting. DM resistant cucumber plants of the present invention may exhibit an increase in fruit yield after inoculation or infection with DM relative to a control cucumber plant inoculated with DM. In one aspect, the resistant cucumber plants exhibit a 2%, 5%, 10%, 15%, 20% or more increase in fruit yield, based upon the total mass, number, or total volume of fruit, relative to a control cucumber plant after one or more rounds of inoculation or infection with DM. The present invention provides for and includes cucumber plants that exhibit resistance to one or more races of DM. In some embodiments, the cucumber plants of the present invention exhibit resistance to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more races of DM. The present invention provides for a seed of a cucumber plant capable of producing a plant having DM resistance. In one aspect, the cucumber plant can be an open-pollinated variety, a hybrid parent inbred line, or a male sterile line. In another aspect, the invention provides seed of a cucumber plant capable of producing a hybrid cucumber plant having DM resistance. The cucumber plants of the present invention can be cucumber lines adapted for greenhouse cucumber production or for field cucumber production. In one aspect, the cucumber plants of the present invention are adapted for greenhouse cucumber production. The present invention also provides a hybrid cucumber having DM resistance. In another aspect, the present invention provides a hybrid cucumber exhibiting DM resistance after inoculation or infection with DM. Commercially valuable cucumber plants represent one aspect of the present invention. In one aspect, certain cucumber traits, including, for example, fruit size, shape, color, weight, taste and fruit yield may be important to the commercial value of the crop. Fruit size, and shape, may be of particular interest if the cucumbers are grown for processing such as pickling. The present invention provides for a cucumber plant that produces a cucumber fruit having a length of about, or greater than about, 11, 12, 13, or 14 cm. In another aspect, a cucumber plant of the present invention produces a cucumber fruit having a length between about 11 and 13 cm, 12 and 14 cm, and 11 and 14 cm. In some aspects, a cucumber plant of the present invention may produce a cucumber fruit having a weight at harvest of about or greater than about 80, 85, 90, 95, 100, 105, 110, 115, 120, and 125 grams. In other aspects, a cucumber plant of the present invention produces a cucumber fruit having a weight at harvest between about 80 and about 125 grams, about 90 and about 115 grams, about 100 and about 120 grams, about 90 and about 125 grams, about 95 and about 125 grams, about 100 and about 125 grams, or between about 115 and about 125 grams. Fruit weight is measured by weighing individual cucumber fruit on a scale. Mature cucumber fruit produced by DM resistant plants of the present invention may have a diameter from about 10, 11, 12, 13, or 14 mm or larger. In some embodiments the diameter of the cucumber fruit may be from about 10 to about 11 mm, or from about 10 to about 12 mm, or from about 11 to about 13 mm, or from about 12 to about 14 mm, or from about 13 to about 14 mm. A cucumber fruit attribute such as shape, weight, or size can be measured or evaluated at a variety of times. In one aspect, an attribute is measured following growth in a growth chamber. In another aspect, an attribute is measured at the time of harvest. In yet another aspect, an attribute is measured after storage of the cucumber fruit at ambient conditions for one day, two days, three days, four days, five days, six days, seven days, eight days, nine days, ten days, eleven days, twelve days, thirteen days, two weeks, three weeks, four weeks, or five weeks after harvest. In one embodiment, a cucumber fruit from a cucumber plant having DM resistance has an overall fruit quality rating of 1, 3, 5, 7, or 9, where fruit quality is measured by visual inspection, with a scale ranging from 1=excellent through 9=poor: Rating 1=Excellent; 3=Above average; 5=Average; 7=Below average; 9=Poor; compared to the standard commercial hybrid grown in the area. Fruit Quality relates to fruit color, fruit shape, fruit length and diameter. A further aspect of the invention relates to tissue cultures of the cucumber plants described herein. As used herein, the term “tissue culture” indicates a composition comprising isolated cells of one or more types, or a collection of such cells organized into parts of a plant. Tissue culture includes, but is not limited to, compositions comprising protoplasts and calli. Tissue culture also includes, but is not limited to, compositions comprising plant cells that are present in intact plant tissues, or parts of plants, such as embryo, leaf, peduncle, pedicel, anther, meristem, tip and segments of root, stump and stem, explants, and the like. In one aspect, a tissue culture comprises embryos, protoplasts, meristematic cells, pollen, leaves, anthers or cells derived from immature tissues of these plant parts. Means for preparing and maintaining plant tissue cultures are well known in the art. Examples of processes of tissue culturing and regeneration of cucumber are described in, for example, Fillatti et al., 1987 (Bio/Technology, 5:726-730). In some aspects, tissue culture of the cucumber plants described herein relates to the culture of protoplasts, calli, or plant cells, that are isolated from, or present in, intact parts of the DM resistant plants described herein. In another aspect, tissue culture refers to the culture of protoplasts, calli, or plant cells, that are isolated from, or present in, intact parts of plants of one or more DM resistant cucumber plant lines selected from the group consisting of ASL147-2027, EUR154-1012GY, EUR154-1021GY, GSP33-1094GY, GPN33-1093GY, 03/8020-20_TUP03_DMFL—1, 03/8024-19_TUP03_DMFL—1, and 03/8039-5_TUP03_DMFL—1, and DM resistant progeny thereof, including those produced by crosses or backcrosses. In yet another aspect, tissue culture of the cucumber plants described herein relates to the culture of protoplasts, calli, or plant cells, that are isolated from, or present in, intact parts of the DM resistant plants described herein. Once DM resistant plants are produced, the plants themselves can be cultivated in accordance with conventional procedures. DM resistant progeny may be obtained through sexual reproduction. The seeds resulting from sexual reproduction can be recovered from the fruit of DM resistant plants and planted or otherwise grown as a means of propagation. DM resistant progeny may also be obtained from DM resistant plants through asexual reproduction. Protoplast or propagules (e.g., cuttings, scions or rootstocks) can be recovered from DM resistant plants or parts thereof and may be employed to propagate DM resistant plants. The present invention also provides for and includes a container of cucumber seeds in which cucumber plants grown from greater than 50% of the seeds have resistance or partial resistance to DM. In another aspect, cucumber plants grown from greater than 55%, 65%, 75%, 85%, 90%, 95%, 98%, or 99% of the cucumber seeds in the container have DM resistance. Another aspect of the invention relates to seeds from a cucumber plant selected from the group consisting of all deposited lines as referred to previously, and DM resistant progeny thereof, wherein cucumber plants grown from about 50%, or greater than 50%, of the seeds have resistance or partial resistance to DM. The container of cucumber seeds can contain any number, weight or volume of seeds. For example, a container can contain about, or greater than about, 10, 25, 50, 200, 400, 700, 1000, 2000, 3000, or more seeds. In another aspect, a container can contain about, or greater than about, 1 gram, 5, 10, 15, 25, 100, 250, 500, or 1,000 grams of seeds. Alternatively, the container can contain about or at least, or greater than, about 1 ounce, 2, 4, 8, 10 ounces, 1 pound, 2, 4, 8, 12 pounds or more of seeds. Containers of cucumber seeds can be any container available in the art. For example, a container can be a box, a bag, a packet, a pouch, a tape roll, a foil, a pail, or a tube. The present invention includes and provides for a container of cucumber fruit from cucumber plants having DM resistance. In one aspect, the container contains about 2, 5, 10, 20, 40, 80, 100, or more cucumber fruit. In yet another aspect, the present invention provides a cucumber vine having cucumber fruit from a plant having resistance to DM. One aspect of the invention relates to dried, or otherwise processed, cucumber fruit, produced by a cucumber plant having a genome that comprises at least one genetic locus giving rise to DM resistance when expressed in a cucumber plant. Processed cucumber fruit includes, but is not limited to fruit pulp, stewed cucumbers, canned, pickled, minced, sliced, or crushed cucumber fruit. In some aspects, the dried, pickled, or otherwise processed cucumber fruit, is the fruit of a cucumber plant selected from one or more of the group consisting of all deposited lines as referred to previously, and DM resistant progeny thereof. The present invention provides for an inbred cucumber plant having resistance to DM, wherein the resistance is exhibited when the plant is in contact with DM. In one aspect, the inbred cucumber plant is derived from accession PI197088. The present invention includes and provides for C. sativus plants having at least one allele for a DM resistance trait. The DM resistant cucumber plants can be either heterozygous or homozygous for the DM resistance trait. In one embodiment, the DM resistant trait can be linked to variations in a single gene (e.g., linked to one or more alleles of a single gene). In another embodiment, the DM resistance trait can be linked to variations at one or one or more quantitative trait loci (QTL). In a yet another embodiment, the DM resistant cucumber plants are homozygous for the DM resistance trait. The present invention provides for a C. sativus cucumber plant having a genome that comprises at least one genetic locus that provides DM resistance from a non-C. sativus plant. In some aspects, the DM resistant cucumber plant is selected from the group consisting of all deposited lines as referred to previously, and DM resistant progeny thereof. In one aspect, the genetic locus derived from a DM resistant cucumber plant can be identified using genetic markers. The present invention provides for a DM resistant C. sativus cucumber plant having less than or equal to 50% of its genome derived from a non-C. sativus DM resistant plant. In another aspect, a DM resistant C. sativus cucumber plant can have 50%, 25%, 12.5%, 6%, 3% or less nuclear DNA derived from a DM resistant non-C. sativus plant. In other aspects, a DM resistant C. sativus cucumber plant can have 50%, 25%, 12.5%, 6% or 3% or less nuclear DNA derived from another member of the Cucumis genus that is DM resistant. The present invention provides progeny of cucumber plants having resistance to DM. As used herein, progeny include not only, without limitation, the products of any cross (be it a backcross or otherwise) between two plants, but all progeny whose pedigree traces back to the original cross. In one aspect of the present invention, the progeny contain about 50%, 25%, 12.5% or less nuclear DNA from a DM resistant cucumber plant and expresses the genetic material that provides DM resistance. One embodiment of the present invention provides for a DM resistant cucumber plant that contains a genetic marker linked to one or more DM resistance locus. By “DM resistance locus” is meant a locus that contributes to DM resistance either alone or in combination with one more other DM resistance locus. By “contributes to Downy Mildew resistance” it is meant that the degree of Downy Mildew resistance is increased in the corresponding plant, either when the locus is alone or in combination with one or more other locus. In one embodiment of the invention, a marker linked to one or more DM resistance loci includes one or more of the following: CAPs—21826, CAPs_ENK60, CAPs_ENK59, CAPs—17170, CAPs—17179, CAPs—18229 CAPs—17563/66, and CAPs_ENK70. In another embodiment of the invention, the assayed markers linked to one or more DM resistance loci include each of the following: CAPs_ENK60, CAPs—17170, and CAPs—17563/66. As used herein, linkage of two nucleic acid sequences, including a nucleic acid marker sequence and a nucleic acid sequence of a genetic locus imparting a desired trait such as DM resistance, may be genetic or physical or both. In one aspect of the invention, the nucleic acid marker and genetic locus conferring DM resistance are genetically linked, and exhibit a LOD score of greater than 2.0, as judged by interval mapping for the DM resistance trait based on maximum likelihood methods described by Lander and Botstein, 1989 (Genetics, 121:185-199), and implemented in the software package MAPMAKER (e.g. Lander et al., Genomics 1:174-181, (1987); default parameters). In other embodiments, the marker and region conferring DM resistance are genetically linked and exhibit a LOD score of greater than 3.0, or a LOD score of greater than 6.0, 9.0, 12.0, 15.0, or 18.0. In one embodiment, the marker and region contributing to DM resistance are genetically linked and exhibit a LOD score of between about 14 and about 20. In another aspect, the nucleic acid marker is genetically linked at a distance of between about 0 and about 50 centimorgans (cM) to the DM resistance locus. In other embodiments, the distance between the nucleic acid marker and the DM resistance locus is between about 0 and about 35 cM, or between about 0 and about 25 cM, or between about 0 and about 15 cM, or between about 0 and about 10 cM, or between about 0 and about 5 cM, including less than about 4, 3, 2 or 1 cM. In another aspect, the nucleic acid molecule may be physically linked to a DM resistance locus. In some aspects, the nucleic acid marker specifically hybridizes to a nucleic acid molecule having a sequence that is within about 30 Mbp, or about 20 Mbp, or about 15 Mbp, or about 10 Mbp, or about 5 Mbp of a DM resistance locus. As used herein, two nucleic acid molecules are said to be capable of hybridizing to one another if the two molecules are capable of forming an anti-parallel, double-stranded nucleic acid structure. Conventional stringency conditions are described by Sambrook et al., Molecular Cloning, A Laboratory Manual, 2nd Ed., Cold Spring Harbor Press, Cold Spring Harbor, New York (1989) and by Haymes et al., Nucleic Acid Hybridization, A Practical Approach, IRL Press, Washington, D.C. (1985). Departures from complete complementarity are therefore permissible, as long as such departures do not completely preclude the capacity of the molecules to form a double-stranded structure. Thus, in order for a nucleic acid molecule to serve as a primer or probe it need only be sufficiently complementary in sequence to be able to form a stable double-stranded structure under the particular solvent and salt concentrations employed. Appropriate stringency conditions which promote DNA hybridization, for example, 6.0× sodium chloride/sodium citrate (SSC) at about 45° C., followed by a wash of 2.0×SSC at 50° C., are known to those skilled in the art or can be found in Current Protocols in Molecular Biology, John Wiley & Sons, N.Y. (1989), 6.3.1-6.3.6. In some embodiments, hybridization conditions can be high, moderate or low stringency conditions. Preferred conditions include those using 50% formamide, 5.0×SSC, 1% SDS and incubation at 42° C. for 14 hours, followed by a wash using 0.2×SSC, 1% SDS and incubation at 65° C. The specificity of hybridization can be affected by post-hybridization washes. For example, the salt concentration in the wash step can be selected from a low stringency of about 2.0×SSC at 50° C. to a moderate stringency of about 1.0×SSC at 50° C. to a high stringency of about 0.2×SSC at 50° C. In addition, the temperature in the wash step can be increased from low stringency conditions at room temperature, about 22° C., to moderate stringency conditions at about 50° C., to high stringency conditions at about 65° C. Both temperature and salt concentration may be varied, or either the temperature or the salt concentration may be held constant while the other variable is changed. In some aspects, the wash step can be performed for 5, 10, 15, 20, 25, 30, or more minutes. In another aspect, the wash step is performed for about 20 minutes. In yet another aspect, the wash step can be repeated 1, 2, 3, 4, or more times using the selected salt concentration, temperature, and time. In another aspect, the wash step is repeated twice. A genetic marker profile of a plant may be predictive of the agronomic traits of a hybrid produced using that inbred. For example, if an inbred plant of known genetic marker profile and phenotype is crossed with a second inbred of known genetic marker profile and phenotype it is possible to predict the phenotype of the F1 hybrid based on the combined genetic marker profiles of the parent inbreds. Methods for prediction of hybrid performance from genetic marker data are disclosed in U.S. Pat. No. 5,492,547, the disclosure of which is specifically incorporated herein by reference in its entirety. Such predictions may be made using any suitable genetic marker, for example, SSRs, INDELs, RFLPs, AFLPs, SNPs, ISSRs, or isozymes. Additional markers, such as SSRs, AFLP markers, RFLP markers, RAPD markers, phenotypic markers, SNPs, isozyme markers, or microarray transcription profiles that are genetically linked to or correlated with DM resistance can be utilized (Walton, Seed World 22-29 (July, 1993); Burow and Blake, Molecular Dissection of Complex Traits, 13-29, Eds. Paterson, CRC Press, New York (1988)). Methods to isolate such markers are known in the art. For example, locus-specific SSRs can be obtained by screening a cucumber genomic library for SSRs, sequencing of “positive” clones, designing primers which flank the repeats, and amplifying genomic DNA with these primers. The genetic linkage of marker molecules to DM resistance can be established by a gene mapping model such as, without limitation, the flanking marker model, and the interval mapping, based on maximum likelihood methods described by Lander and Botstein, 1989 (Genetics, 121:185-199), and implemented in the software package MAPMAKER. A maximum likelihood estimate (MLE) for the presence of a marker is calculated, together with an MLE assuming no trait effect, to avoid false positives. A log10 of an odds ratio (LOD) is then calculated as: LOD=log10 (MLE for the presence of a trait (MLE given no linked trait)). The LOD score essentially indicates how much more likely the data are to have arisen assuming the presence of a resistance allele rather than in its absence. The LOD threshold value for avoiding a false positive with a given confidence, say 95%, depends on the number of markers and the length of the genome. Graphs indicating LOD thresholds are set forth in Lander and Botstein (1989), and further described by Ars and Moreno-Gonzalez, Plant Breeding, Hayward, Bosemark, Romagosa (eds.) Chapman & Hall, London, pp. 314-331 (1993). Selection of appropriate mapping or segregation populations is important in trait mapping. The choice of appropriate mapping population depends on the type of marker systems employed (Tanksley et al., Molecular mapping plant chromosomes. Chromosome structure and function: Impact of new concepts J. P. Gustafson and R. Appels (eds.), Plenum Press, New York, pp. 157-173 (1988)). Consideration must be given to the source of parents (adapted vs. exotic) used in the mapping population. Chromosome pairing and recombination rates can be severely disturbed (suppressed) in wide crosses (adapted×exotic) and generally yield greatly reduced linkage distances. Wide crosses will usually provide segregating populations with a relatively large array of polymorphisms when compared to progeny in a narrow cross (adapted×adapted). As used herein, the progeny include not only, without limitation, the products of any cross (be it a backcross or otherwise) between two plants, but all progeny whose pedigree traces back to the original cross. Specifically, without limitation, such progeny include plants that have 50%, 25%, 12.5% or less nuclear DNA derived from one of the two originally crossed plants. As used herein, a second plant is derived from a first plant if the second plant's pedigree includes the first plant. The present invention provides a genetic complement of the cucumber lines described herein. Further provided is a hybrid genetic complement, wherein the complement is formed by the combination of a haploid genetic complement from elite inbred cucumber lines described herein and another haploid genetic complement. Means for determining such a genetic complement are well-known in the art. As used herein, the phrase “genetic complement” means an aggregate of nucleotide sequences, the expression of which defines the phenotype of a plant, such as a C. sativus cucumber plant or a cell or tissue of that plant. By way of example, a C. sativus cucumber plant is genotyped to determine a representative sample of the inherited markers it possesses. Markers are preferably inherited in codominant fashion so that the presence of both alleles at a diploid locus is readily detectable, and they are free of environmental variation, i.e., their heritability is close to, or equal to, 1. This genotyping is preferably performed on at least one generation of the descendant plant for which the numerical value of the trait or traits of interest are also determined. The array of single locus genotypes is expressed as a profile of marker alleles, two at each locus for a diploid plant. The marker allelic composition of each locus can be either homozygous or heterozygous. Homozygosity is a condition where both alleles at a locus are characterized by the same conditions of the genome at a locus (e.g., the same nucleotide sequence). Heterozygosity refers to different conditions of the genome at a locus. Potentially any type of genetic marker could be used, for example, simple sequence repeats (SSRs), insertion/deletion polymorphism (INDEL), restriction fragment length polymorphisms (RFLPs), amplified fragment length polymorphisms (AFLPs), single nucleotide polymorphisms (SNPs), and isozymes. Considerable genetic information can be obtained from a completely classified F2 population using a codominant marker system (Mather, Measurement of Linkage in Heredity: Methuen and Co., (1938)). An F2 population is the first generation of self or sib pollination after the hybrid seed is produced. Usually a single F1 plant is self or sib pollinated to generate a population segregating for the nuclear-encoded genes in a Mendelian (1:2:1) fashion. In contrast to the use of codominant markers, using dominant markers often requires progeny tests (e.g., F3 or back cross self families) to identify heterozygous individuals. The information gathered can be equivalent to that obtained in a completely classified F2 population. This procedure is, however, often prohibitive because of the cost and time involved in progeny testing. Progeny testing of F2 individuals is often used in map construction where error is associated with single plant phenotyping, or when sampling the plants for genotyping affects the ability to perform accurate phenotyping, or where trait expression is controlled by a QTL. Segregation data from progeny test populations (e.g., F3 or backcrossed or selfed families) can be used in trait mapping. Marker-assisted selection can then be applied to subsequent progeny based on marker-trait map associations
{'application_number': '<application-reference appl-type="utility">\n<document-id>\n<country>US</country>\n<doc-number>12424452</doc-number>\n<date>20090415</date>\n</document-id>\n</application-reference>', 'publication_number': '<publication-reference>\n<document-id>\n<country>US</country>\n<doc-number>20090265803</doc-number>\n<kind>A1</kind>\n<date>20091022</date>\n</document-id>\n</publication-reference>', 'source_file': './application/2009/ipa091022.xml', 'source_data': 'USPTO-Application'}