Cytoplasmic Effects and Heterosis in Cytoplasmic Male Sterile Line of Leafy Mustard 0912A

Male sterility and seeding ability of the cytoplasmic male sterility line of leafy mustard (0912A) (Brassica juncea) were evaluated by fertility and floral characters. With 0912A and its maintainer line (0912B) as maternal parents and five typical inbred lines as male pa-rents,ten F₁ hybrids were produced to study the effects of male sterile cytoplasm and heterosis.The results showed that the sterility of 0912A was steadily complete,the fertility and sterile plant rate were 100%,and the seed-set was normal.The heterosis of yield-related traits was obvious, but not for the quality traits.Male cytoplasm had a distinct negative effect on weight per plant,but the heterosis of hau cytoplasmic F₁ was still significant.The male cytoplasmic effect on hybrid traits varied with different nuclear genetic background,and the negative effect of cytoplasm could be reduced or eliminated by choosing suitable male parents.