Karpenko O. The role of minor genes in a genetic control of the Moldavian type of cytoplasmic male sterility of maize

Object: the cytoplasm of the Moldavian type of male sterility of maize. Aim: to determine of the minor genes role in a genetic control of the Moldavian type of cytoplasmic male sterility of maize Methods: breeding, cytological, statistic. Novelty: it was proved that pollen fertility is caused not only by action of major gene Rf3 but and action by another genes named minor. It was determined that minor genes are dominant and non allelic to Rf3. Cumulative character of action of minor genes was proved. Minor genes are independent in recessive genotypes by major gene and enhance its expressivity if Rf3 is dominant. Results: The regularity of the lines behavior in S-type crosses has been determined. The genotypes with a stable high level of fertility with the recessive major rf3 gene in the presence of the Moldavian sterility factor have been obtained. It was proved that minor genes were different in action force. The influence of minor genes on fertility restoration of heterozygotes and the degree of pollen grains fertility have been determined. According to the obtained data there is a reason to assume that the lines with a partial fertility have minor genes in a dominant state. Application stage: the line of maize with minor genes complex and absolute fertility was found. It is a derivation of minor genes. Application area: research establishments of UAAS, MinAP of Ukraine