Genetic Analysis And Molecular Marking Of Resistance Of Bacterial Wilt Of Eggplant

The bacterial wilt of eggplant is the soil-diffused desease that is caused by Ralstonia solanacearum. The bacterial wilt of eggplant is one of the main diseases of eggplant, threatening culturing and production of eggplant, particularly in the area of Changjiang river of China. Resistant breeding is the most basic and effective method to resolve the problem, for there are no efficient measures to prevent and control the disease by now. The resource of resistance germplasm and genetic analysis of resistance are the precondition and base, the work of collecting and screening the resistance resource has been carried on at home and abroad, and analyzing the law of the resistance, but the results of the experiment are not unanimous for different materials and other reasons. So it is significant to study the law of resistance to bacterial wilt. In this study, the materials 509,533, F₂ and F₃ accessions which were screened from the local varieties of China were utilized, analyzing the law of the resistance to bacterial wilt and marking the resistant gene to the bacterial wilt with AFLP markering, The results are as following:1. The results of genetic law of the resistance: the F1 crossing accessions between the resistant parent and susceptible parent is resistant to the bacterial wilt, among the F2 segregate population of 78 plants, the resistant plants account for 64(including 20 resistant plants and 44 plants of middle resistance), meanwhile, the number of the susceptible plants is 14. According to the dominance in the Fl and classic 3:1 ratio of the resistance plants and the susceptible in the F2, the conclusion is drawn that the resistance to bacterial wilt in the eggplant is dominant and controled by one gene.2. The resistant and susceptible parents and their F2 progenies were analyzed with the AFLP of MseI and EcoRI. Screening 426 pairs of the combinations of AFLP primers, there are 51 pairs primer-combinations showing 97 polymorphism bands between the parents. Different primer combinations amplified different number of bands, range from 1-5 bands, the polymorphism bands of theirs may be linked to the resistant gene.3. With the F₂ segregate population, combining the evaluation result of resistance of the F2 segregate population, the marker E42M48 linked to the resistant gene of bacterial wilt was obtained, the special band is about 320bp,the exchange rate is 7.69%, the genetic distance between the marker and the resistant gene is 7. 75 cM.