CYTOGENETIC STUDIES OF TRANSEC — A WHEAT-RYE TRANSLOCATION LINE

Publisher Website
Google Scholar
Abstract
Transec was produced by the X-irradiation of the Cornell Wheat Selection 82a 1-2-4-7, a line that possesses a pair of rye telocentric chromosomes bearing resistances to wheat leaf rust [ Puccinia recondita] and wheat powdery mildew [Erysiphe graminis tritici]. The translocated segment of rye involved in Transec bears both of these resistances. The F1 of Transec X 82a 1-2-47 possesses a trivalent involving an entire wheat chromosome, the translocation chromosome and the rye telocentric. Observations on this trivalent indicate that the translocated alien segment occupies a terminal position and is of considerable length. The wheat chromosome involved in the translocation has been identified by monosomic analysis as chromosome 4A. The translocation chromosome is transmitted through 50% of eggs of heterozygotes. Heterozygotes involving relatively high and relatively low male transmission of the translocation chromosome have been isolated. It appears that this difference in male transmission, which varies from 45.5% to 20%, is heritable.