VARIATION IN POLLEN STERILITY CONTROLLED BY CYTOPLASM IN THE SUGAR-BEET (BETA-VULGARIS L) AND ITS ASSOCIATION WITH HETEROPLASMIA OF MITOCHONDRIA IN CELLS

Population-genetic models of sorting (segregation) of organelles (mito chondria) in heteroplasmic cell populations are considered. Heteroplas mia is the most probably reason for variation in cytoplasmic male ster ility in beet populations. This assumption allows us to explain the fo llowing phenomena within the framework of a single concept: cytoplasm conversion (interchange of N and S plasmotypes), low frequency of gene s for sterility maintenance in populations, mosaicism of flowers accor ding to expression of male sterility in individual plants, etc. The mo del of mitochondrial sorting in cell populations is based on molecular -genetic investigations of differences in DNA composition in fertile p lants and their sterile analogues.