Cytogenetics of a hybrid and amphiploid between Hordeum pubiflorum and Secale africanum

Abstract

A low frequency (0.86) of rod bivalents was observed at metaphase I of meiosis in the F1 hybrid between Hordeum pubiflorum 2x and Secale africanum 2x. Seeds were obtained from colchicine-doubled sectors on the hybrid. An average of 2.49′ + 12.77″ per cell characterized meiosis in the amphiploid. The univalent and bivalent frequencies among Hordeum and Secale chromosomes were approximately equal, although there was a higher proportion of ring bivalents formed by the Hordeum chromosomes. Over 90% of the pollen was stainable, but only 40% seed set was obtained on the amphiploid. Although the seeds were badly shrivelled, some were viable.Key words: intergeneric hybrid, chiasma frequency, embryo rescue, Hordeum–Secale.