Abstract:

Adzuki bean is an important legume crop in China and East Asia. To investigate the genetic diversity in the cultivated adzuki bean germplasm and to provide information for parental selection and germplasm improvement, ninty-three adzuki bean germplasm, including 8 released cultivars and 85 land varieties (Table 1), were analysed with random amplified microsatellite polymorphism (RAMP) markers. PCR was performed with 5’ anchored primers complementary to microsatellites in combination with random primers. The results showed that: (1) A total of 308 RAMP bands were obtained with 42 informative primer combinations, of which 297 bands (96.43%) were polymorphic. A mean of 7.1 polymorphic bands was detected for each RAMP primer combination ranging from 3 to 17 (Table 2). (2)The total heterozygosity (Ht) of RAMP loci in the adzuki bean resources was 0.693. Nei and Li’s genetic similarity (GS) coefficients ranged from 0.506 to 0.934. The mean genetic distance based on the GS values among the materials was 0.281 ranging from 0.066 to 0.494. It is revealed that there was sufficient genetic diversity in the studied materials but the genetic base of these materials was narrow. (3)Clustering analysis was made with unweighted pair group method for arithmetic averages (UPGMA) using the symmetric matrix of similarity coefficients. The 93 materials were clustered into five groups (Fig.2). The group Ⅱ included three subgroups. The dendrogram revealed that the cluster pattern showed obvious correlation with the growth characteristics and the locations of the cultivated adzuki bean. (4)Heterogenous germplasms should be introduced into the cultivated adzuki bean to enlarge the genetic base and to create excellent new germplasms for the improvement of adzuki bean varieties.

Key words: RAMP(random amplified microsatellite polymorphism), Adzuki bean (Vigna angularis), Germplasm resources, Genetic diversity