Effect of genetic diversity in Hordeum vulgare L. and Secale cereale L. ontheir crossability and the development and viability of hybrid embryos andplants

A study was made of the effect of genetic diversity in cultivated barley an d rye on seed setting, embryonic development, and viability of barley x rye hybrids grown in vitro and planted. The variation in seed-setting frequenc y was shown to be determined mainly by vegetation conditions and random fac tors, while the variation in proportion of seeds with embryos among the tot al seed set was determined by the genetic diversity of barley and rye. Sele ction of barley genotypes was shown to increase the yield of viable barley x rye hybrids. Based on the phenotypic analysis of barley x rye hybrids obt ained in various combinations, low viability and hybrid lethality were attr ibuted to the hybrid necrosis genes expressed from early ontogeny. These ge nes are assumed to be widespread among barley and rye varieties.