A generic SSR marker closely linked to a dominant genic male sterility gene (DGMs79-399-3) in broccoli (Brassica oleracea var. italica)

Abstract

As an important pollination system, male sterility has been used widely for broccoli (Brassica oleracea var. italica) hybrid production. New male sterile lines are important for broccoli breeding. We transferred the dominant genic male sterility (DGMs) 79-399-3, which was developed from a spontaneous mutation in cabbage, to broccoli. In this study, molecular markers linked to the DGMs79-399-3 gene in broccoli were identified by screening a segregating population DGMs8554 with 747 individuals, obtained by ten backcrosses (BC10) using a cabbage-dominant genic male sterility line containing DGMs79-399-3 as the donor and broccoli inbred line 8554 as the recipient. Bulked segregation analysis with respect to male sterility and fertility for the BC10 population of DGMs8554 was conducted by scanning 2585 different types of primers. Three SSR and one SCAR marker were identified, and a map surrounding DGMs79-399-3 was constructed. Two flanking markers, scaffold10312a and scaffold129_2012, were linked to the dominant male sterile DGMs79-399-3 gene at distances of 0.563 and 0.328 cM, respectively, which mapped the DGMs79-399-3 gene to a 0.891 cM range. The markers were verified in another three broccoli groups, and a generic SSR marker, scaffold10312a, was obtained with an accuracy ≥96.43 %. The markers developed here will accelerate the breeding of new elite DGMs lines in broccoli and provide a solid basis for cloning of the DGMs79-399-3 gene.