Barley × rye hybrids eliminating accessory chromosomes of rye

Abstract

Eighty‐six emasculated spikes of 5 barley varieties were pollinated by ‘Transbaikal’ rye carrying 2 to 6 B chromosomes. Five F1 plants survived to be chromosome‐counted. Two of them were barley haploids (2n = 7) and three were barley × rye hybrids. Two of the hybrids withered away before producing spikes. The chromosomal constitution of the hybrids was analysed at intervals using Giemsa C‐banding. Basically, the hybrids had a full barley and a full rye genome. At the seedling stage (7 weeks after crossing), some cells of one hybrid carried one rye standard B chromosome in addition, and some cells of two hybrids carried one or two long arm rye iso‐B chromosomes in addition. Three months after crossing, all rye B chromosomes were eliminated. Both mitotic and meiotic cells showed variability for the number of rye A chromosomes. It will hardly be possible to incorporate rye B chromosomes permanently in barley. © 1991 Mendelian Society of Lund