RAPD Analysis Of Genetic Diversity And Genetic Relationship Among Ecotypes Of Adzuki Beans(Vigna Angularis)Germplasm

Adzuki bean (Vigna angularis) originated from our nation, and had long cultivation history. It is very important to detect the genetic diversity of wild ,weedy and cultivated adzuki beans for further researching the process of diffusion, evolution and the origin of adzuki bean germplasm resources. RAPD variation was assessed in 163 accessions of adzuki bean from China, Japan, Korea, Bhutan, Nepal and Vietnam. 285 bands, including 261 polymorphic bands, were detected by 27 RAPD primers. There were species-specific bands in the three races ;The order of Genetic dispersion was: wild adzuki bean＞weedy adzuki bean＞cultivated adzuki bean, and the order of Gst was: wild adzuki bean＜weedy adzuki bean＜cultivated adzuki bean;The weedy adzuki bean has close genetic relationship with wild adzuki bean assessed by the difference of genetic dispersion; From the average of genetic similarity coef., relative close genetic relationship was observed in the weedy adzuki bean,whereas the wild and cultivated adzuki bean,as two pole of evolution,have high genetic variation;The material from Southwest China and South Japan has relatively high genetic dispersion,low Gst and average of genetic similarity coef; The cluster analysis showed that eight groups can be clustered when genetic similarity coef. was given as 0.32. It appeared that the cluster has obviously associated with the genetic races and different adzuki bean geographical regions.　The morphological characteristics of different ecotypes of adzuki bean germplasm resources which could grew normally in Beijing were conducted in the present study. The results showed that the morphological diversity was high among and in different ecotypes. In the process of evolution from wild adzuki bean to the cultivated adzuki bean, biometric average of HGT factors (plant high, tip tendril and no.of nods on stem) and MAT reduced based on the analysis of biometric average changing trend. Weed adzuki bean showed intermediate features between wild and cultivated adzuki bean. The average diversity index of weed and cultivated races of adzuki bean had no significant difference, and both were relatively higher than that of wild adzuki bean (0.9725). The results on genetic diversity diversity and differentiation among various ecotypes revealed from morphological and agronomic traits coincided with the conclusion obtained from molecular marker analysis.