Tobacco Germplasm Bacterial Wilt Resistance Identification And Molecular Marker Screening

Bacterial wilt, caused by bacterial pathogen Ralstonia solanacearum is one of the most serious soil-borne bacterial plant diseases. Tobacco bacterial wilt has generally taken place in the major tobacco-growing areas of the world and the vast majority of southern china, which has seriously become a regional influence of the output and quality of tobacco, causing enormous losses to the local economy. Agro-chemicals were mainly used for the control of this disease in practice, but the prevention is ineffective and easy to cause environmental pollution. Studies have shown that developing resistant cultivars was the most effective way to control the disease. However, resistance to bacterial wilt of tobacco germplasm resources is scarce so far. The bacterial wilt resistance performance of tobacco germplasm should be identified as well as the inheritance of resistance resources shoud be analyzed. Furthermore, it is necessary to develop new resistant cultivars with traditional breeding and molecular marker-assisted selection breeding.The major results about this study are as following:1. In this study, the bacterial wilt resistance performace of forty-seven tobacco germplasm were identified by floating pool temperature-controlled water inoculation methods. The results of identification showed that two germplasms (Coker176and NCI02) were of resistance.2. The bacterial wilt resistance performance of four tobacco germplasms(resistant varieties R8,susceptible varieties Honghuadajinyuan,F1, F2and BC1F1) were identified. The results showed that the resistance to the bacterial wilt in R8was controlled by additive genes.3. Three marker(TP398,TP133and TP131) linked with the gene resistance to the bacterial wilt was found.