Identification of Maintainer Genes in Brassica napus L. for the Male-Sterility-Inducing Cytoplasm of Diplotaxis muralis L.

Male fertility of F¹ interspecific hybrid plants derived from crosses between cytoplasmic male-sterile Brassica campestris in Diplotaxis muralis cytoplasm and 147 B. napus cultivars was Investigated. F¹, plants obtained, from crosses with the B. napus cultivars‘Mangum’and‘Hinchu’were male-sterile while F¹ plants derived from all other crosses were male-fertile. This indicated that these two cultivars carried maintainer genes far the male-sterility-inducing cytoplasm of D. muralis. Sterility was stable In plants derived from backcrosses of male-sterile F; plants with‘Mangun and‘Hinchu’but the seed set of backcross plants was low. With restorer genes readily available in B. napus, these findings could lead to the development of a new cytoplasmic male sterility system for the breeding of B. napus hybrid cultivars.