DNA markers in onion (Allium cepa L.) cytoplasmic male sterility study

The work is carried out in the framework of the onion F1 breeding program. The practical purpose of the work is to carry out genetic selection of onion forms using molecular genetic markers of male sterility in the course of obtaining the maternal line for heterotic selection of F1 hybrids. The scientific component of these studies was the study of the population-genetic basis of various types of male sterility in onions of the Belarusian genmplasma. We used belarusian varieties Vetraz and Skarb litvinov and a collection of other varieties and hybrids. Markers of the mitochondrial genes orfA501, cob and the nuclear alleles Ms/ms, cosegregating with genes of fertility restorer/S-sterility maintainer genes, were studied. It has been shown that in the Vetraz variety are observed plants with the N- or T-cytotype in N-cytoplasm (TN-). The belarusian variety Scarb litvinov contains plants with the cytotypes N-, S, TN-, SN-, STN-. As a result, it was concluded that the male sterility of the Vetraz variety is T-type, and in the Scarp litvinov variety is complex, and is caused by the cytoplasmic alleles S- and T-. In both varieties: Vetraz and Scarb litvinov the sources of the ms locus causing the S-type of male sterility have been identified. Less than one-fifth of the number of world collection of varieties and hybrids was detected as S-cytotype. This value is smaller than the value given in the scientific literature. However it may reflect the significant spread of the original S-cytoplasm of a single plant of the shortday Italian Red variety in the world onion germplasm.