Studies On Inheritance And Molecular Marker Of Clubroot Resistance In Brassica Rapa Chinensis

Brassica rapa chinensis is a kind of important green leafy vegetables in our country, in the region south of the Yangtze river basin and extensive cultivation As a kind of soil spread diseases, the root of the cruciferous vegetables, including Brassica rapa chinensis, harm shows the tendency of increase. Once root soil bacteria pollution is hard to thoroughly, no longer cruciferous vegetables growth well. The Chinese cabbage, cabbage, cauliflower and rape clubroot researches on Chinese cabbage clubroot disease research. This experiment is to study the Brassica rapa chinensis clubroot, the main research contents are as follows:1. Clubroot inoculation evaluation in Brassica rapa chinensisThrough the injection method, bacteria indigenous and dipping root method of the three typical inoculation method comparison, it was found that the injection caused the disease index of the highest root dipping although induced the highest incidence, but will also cause a high death rate of, considering, injection method is more suitable for inoculation and identification of a large number of materials. Through inoculation time test, it was found that the whole growth period of Chinese cabbage can be susceptible to disease, and the early onset of infection is more severe. 1*106/g(dry soil) was found to be the ideal inoculation concentration by comparing different concentration inoculation. Obvious root swelling was observed at 30 days, and 45 days of inoculation were the most accurate time.2. Inheritance of Clubroot Resistance in Brassica rapa chinensisBy inoculation identification of F2 population, according to the Anti Sense disease situation analysis of the clubroot resistance was controlled by single dominant genes controlling and other minor genes.3. Brassica rapa chinensis clubroot resistance markerFrom 21 primers screened in male, female, F1 and F2 groups stable amplified specific bands of a primer, and through the detection of the individual DNA in F2 population found resistance genes in F2 population recombination exchange, the exchange rate is about 9.73% and by ISSR marker screening and disease resistant gene closely linked CR labeled and genetic distance for 9.86cM.