Genetic control of the rate of transmission of rye B chromosomes. II. OB x 2B crosses

Abstract

Twenty ♀ 0B x ♂ 2B crosses were made in which a single male was crossed with four different females, and the character ‘mean number of Bs per plant in the progeny’ was analysed. The 2B plants used as males and the OB females belonged either to low or to high transmission rate lines, previously selected. The genetic basis of the difference between the high and low transmission rate lines was statistically tested. The male group (high or low class of the 2B male) has a significant effect on the progeny, while the female group (high or low class of the OB female) has no significant effect. The genes controlling the transmission rate of B chromosomes affect the proportion of OB vs. 2B plants in the OB x 2B cross, but this is not a result of any effect on the nondisjunction mechanism, since the proportion of IB plants is low in all cases. Structural variants of B chromosomes appeared de novo at a high frequency. © 1995 The Genetical Society of Great Britain.