DISTORTED SEGREGATION FOR MILDEW RESISTANCE IN DOUBLED HAPLOID LINES OF SPRING BARLEY

The mildew reactions of the second generation of doubled haploid (DH) plants, derived from anther culture of crosses among three spring barl ey lines carrying different Mla mildew resistance alleles and the cv. 'Pallas', were analyzed by using a set of three European and one Israe li mildew isolate. The results indicated, (1) a significant level of d istortion segregation in favour of resistant DH genotypes, which was p ossibly due to linkage of mildew resistance genes on chromosome 5 with genes for plant regeneration and (2) various degrees of dominance for the different resistance genes studied as well as the possible action of modifier genes.