Mining And Utilization Of Source For Bruchid Resistant Gene In Mungbean

Mungbean (Vigna radiata (L.) Wilclzek) is one of the main edible beans in China, while bruchid is a very serious pest for the development of mungbean production, and the damage brought by Callosobruchus chinesis (L) is the greatest. They can be found at any places where mungbean is cultivated or stored. Pestcndes are always used to prevent bruchid in the past, but the residue of them would be great environmental pollutions. Thus, the best way to prevent this damage is to develop new mungbean cultivars that immume or highly resistant to bruchid.Total of 4 accessiones of mungbean germplasm were identified to be resistant to bruchid from 1520 accessions of mungbean resources. They are two wild types, TC1966 and ACC41 (both of them are high resistant to bruchid, HR) and two cultivars, V2709 (resistant, R) and V2802 (mid- resistant, MR). These four accessions show resistance to both C. chinesis and C. maculates, but their adaptability to environment and agricultural traits need to be improved before they can be used for production.All F₁ plants from cross between VC1973A/TC1966 show resistant to bruchid, and the ratio of resistant and sensitive individuals in F₂ population is about 3:1. This suggests that the resistance in TC1966 is controlled by one dominant gene. Genetic studies using the three resistant germplasm TC1966, V2709 and V2802 showed that bruchid resistance in each resistant line was controlled by single dominant gene and the resistant genes in them might be non-allelic. The separation ratios of resistance in F₂ derived from combinations of V2709/TC1966 and V2802/TC1966 are about 15:1, while in combination of V2709/V2802, the ratio is not 15:1 in F₂ population, suggesting that interactions might be occurred or the two kind of resistant genes.A co-dominant marker that related with the resistant gene was identified using PCR technique. A specific fragment of about 1.79kb was found in TC1966 and the resistant progeny, while a fragment of about 1.03 kb was found in VC1973A and sensitive individuals. At 7 loci, different DNA fragments were found in TC1966 and its progeny, comparing to V2709, V2802 and 6 cultivars that sensitive to bruchid by PCR analysis.107 lines that resistant to bruchid were developed by hybridization and recurrent selections. After evaluation on their agronomic trais, nutrition level, resistant to bruchid, disaeses and environmental stress, and their genetic diversity and commodity value, 17 elite and resistant germpalsm were found, and 14 of them show high resistance to bruchid. After comparison in yield test, 3 best lines were selected for evaluations of national or local mungbean yield trails and exhibitions. And a new cultivar zhonglv No.4 was approved released by the National Crop Variety Appraial Committee.