The Preliminary Evaluation Of The Insect-resistant Cabbage And The Breeding Of Male Sterile Line

Diamondback moth (Plutella xylostella) is a pest which causes great loss of cruciferous vegetables, and in recent years the destroy caused by diamondback moth tend to be more serious. As the overdosage of pesticide, the traditional control methods have come across a big challenge especially when diamondback moths’resistance to pesticide has become higher gradually. Moreover, the transgenic insect-resistant varities are not available in production and market now. Thus, it will be very important to breed the insect-resistant varities through traditional breeding.Using self-incompable lines and using male sterility lines to develop hybrid varity are the major methods in cabbage (Brassica oleracea) breeding. Compared to self-incompable lines breeding, lots of disadvantages can be overcome in complete pollen-cytoplasmic male sterity lines’ breeding, just like purity of seeds and hybrid degeneration, which appear frequently in the self-incompable lines’ breeding. The insect-resistant male sterity lines, which are produced by back-crossing, can provide very useful and valuable resources for cabbage breeding in the future.The major contents and results of the research:1. In this research, F1progeny is derived from2portions of pest-resistant inbred lines and4portions of normal inbred lines. And after measuring the agronomic and quality characters as well as evaluatin the resistance of F1progeny and parents to diamondback moth in different ways, like in net, in vitro and in natural situations, we make a conclusion that the hybrid progeny exhibit the positive mid-parent heterosis in some cases, especially in agronomic characters which is weaker than quality characters.2. For the investigation of insect-resistance performed in natural situation may be effected by lots of factors, so there is an obvious difference in the results compared to that performed in net and in vitro. According to the surveys performed in net and in vitro, we can observe the trend of insect-resistance shows a great consistency even in different materials, but if we assess the data according to the susceptible levels to insect, the trend will show some differences.3. In the research, hybridization and backcross have been performed with female parent kale Yu, a cytoplasmic male sterile lines, and male parent resistant kale K. And the results shows progenies form F1and BC1generation exhibit positive mid-parent heterosis in most agronomic and quality characters. However, as the time of backcrossing increased, the characters of backcross progenies become more and more similar to their male parent, insect-resistant cabbage K. And all pollens from F1and BC1progeny are completely sterile.4. Insect resistance testing has been performed among parents, F1and BC1progeny. And the data indicates that the resistance of F1and BC1generation trends to increase gradually, more closely to that of their male parent, insect-resistant cabbage K.