the source parent, leaf color depended greatly on which parent had which trait. For instance, pollinating an ovule from a white branch with pollen from another white area resulted in white progeny, the predicted result for a recessive gene. Green pollen used on a green stigma resulted in all green progeny, the expected result for a dominant gene. However, if green pollen fertilized a white stigma, the progeny were white, but if the sexes of the donors were reversed (white pollen on a green stigma), the progeny were green. This non-mendelian inheritance pattern was later traced to a gene named iojap which codes for a small protein required for proper assembly of the chloroplast ribosome. Even though iojap assorts according to Mendel's rules, if the mother is homozygous recessive, then the protein is not produced, the chloroplast ribosomes fail to form, and the plasmid becomes non-functional because the ribosomes cannot be imported into the organelle. The progeny could have functional copies of iojap, but since the chloroplasts come exclusively from the mother in most angiosperms, they would have been inactivated in the previous generation, and so will give white plants. Conversely, if a white father is paired with a green mother with functional chloroplasts, the progeny will only inherit functional chloroplasts, and will thus be green. In his 1909 paper, he established variegated leaf color as the first conclusive example of cytoplasmic inheritance. His son Carl Wilhelm Correns became a geologist, his second son Erich Correns (chemist) a chemist, his daughter, Anna-Eva Correns, a medical doctor. References External links Article relating the work of Gregor Mendel 19th-century German botanists Phycologists Bryologists Pteridologists German geneticists German mycologists Scientists from Munich 1864 births 1933 deaths 20th-century German botanists Max Planck Institute directors