Molecular Markers And Mapping Of Anthracnose Resistant Gene In Common Bean (Phaseolus Vulgaris L.)

Anthracnose is one of the most important diseases of Common bean throughout the word. Growing resistant cultivars is the most economic, effective and environmental strategy to control this disease. However, due to the high variability of Colletotrichum lindemuthianum and the continual emergence of new races, genetic resistance in the host is not durable. So it must continue to explore new resistant genes. At the same time, we must make clear the distribution and variability of Colletotrichum lindemuthianum when breeding the resistant cultivars. The purpose of this study is to explore the new resistant gene from Chinese Common bean landrace which resistant to anthracnose.In this study, we identified 15 strains of Colletotrichum lindemuthianum and 181 accessions by inoculation artificially. We make clear the gene pool origin of 54 resistant accessions through SDS-PAGE analysis of common bean phaseolin. And last, we analyse three F2 segregate populations by Bulked Segregant Analysis (BSA) and microsatellite polymorphism. The main results as follows:1. The distribution and variability of Colletotrichum lindemuthianum was evaluated. Fifteen Colletotrichum lindemuthianum strains from 8 provinces including Heilongjiang, Jilin, Neimenggu, Hennan, Yunnan etc. were identified and 5 races were identified, of which the race 81 is the dominant race of China and the frequency reached up to 67%.2. The resistance of the 181 landraces was characterized. There were 2 accessions with high resistance, 43 with resistance and 33 with high susceptible among 181 common bean accessions. It indicated that there were notable differences between the accessions on the resistance to the race 81 and the resistant germplasm is very abundant in Chinese Common bean.3. The origin of 54 common bean landraces with resistance to anthracnose was traced by phaseolin marker. Among the 54 anthracnose resistant accessions ,28 from Andean gene pool and 26 from Mesoamerican. The Red Flower Common bean and the Red Common bean are from Andean gene pool.4. The resistance to the 81 race of The Red Flower Common bean and the Red Common bean was controlled by one single dominant gene. We named the resistant genes in The Red Flower Common bean as Co-F2533 temporarily.5. Through polymorphic analysis of microsatellite markers and genetic linkage analysis, 4 SSR markers including Clon1429, BM170, BMD37 and Clon410 on linkage group B6 were found linked to Co-F2533 with genetic distance of 18.4cM, 6.6cM, 20.9cM, and 30.9cM respectively. The order of the resistant gene and the markers on the chromosome was Clon1429- Co-F2533- BM170- BMD37- Clon410.6. Co-F2533 is a new anthracnose resistant gene because there is not any known anthracnose resistant gene on linkage B6 at present.