THE STUDY OF GENETIC-CONTROL OF MEIOSIS I N RYE

Results of long-term studies of genetic control of meiosis in rye are considered. The material for study was obtained using inbreeding, whic h included an effective method, developed by the authors, of applicati on of inbreeding in studies of plant heterozygosity in rye populations . Mutations that disturb different stages of meiosis (mei-mutations) w ere found among sterility mutations that segregate in initial generati ons of inbreeding. Synaptic mutants with univalents at MI were most fr equent in the obtained genetic collection. These mutations are inherit ed as monogenic and recessive. Electronic microscopic study of synapti c mutants showed that some of them were complete or partial asynaptics , while the others are characterized by switches from homologous to no nhomologous associations during formation of structures of the synapto nemal complex (SC). Some meimutations probably cause changes in the ev ents that determine normal organization of the meiotic cycle; other mu tations determine disturbances in processes that lead to spindle forma tion and functioning. During study of meiosis in lines that were subje cted to long-term inbreeding, a spectrum of nonspecific polygenic abno rmalities of meiosis was detected. These abnormalities can be an expre ssion of inbred depression.