A male sterile line with dominant gene (Ms) in cabbage (Brassica oleracea var. capitata) and its utilization for hybrid seed production

A male sterile plant, 79-399-3, was identified from a spring cabbage line 79-399 in 1979. Light-microscopic studies with paraffin section indicated that meiotic division stopped at the tetrad stage. The ratio of male sterile plants to fertile plants in the progenies of test crosses was 1:1 in five experiments conducted in 1982 and 1991-1994. However, some male sterile plants were sensitive and developed a very low number of viable pollen grains. When sensitive male sterile plants were selfed, the progenies segregated into male sterile and fertile plants at a ratio of 3:1. The male sterile plants from selfing of sensitive male sterile plants were propagated by tissue culture and crossed with different inbred lines. From the progenies of the crosses, populations with 100% male sterile plants were observed. The results indicated that homozygous dominant male sterile (MsMs) plants segregated from the selfed progenies. Populations with 100% male sterile plants and stable male sterility were developed as male sterile lines. Several favorable combinations were also selected by crossing the male sterile lines with inbred lines with high combining ability for desirable horticultural characters.