Genetic Diversity of Pigeonpea (Cajanus cajan (L.) Millsp.) Cultivars and Its Wild Relatives Using Randomly Amplified Polymorphic DNA (RAPD) Markers

Genetic diversity among and between 16 cultivars of pigeonpea (Cajanus cajan (L) Millsp.) and its wild relatives (C. albicans and C. lineatus) analysed using RAPD. Twenty two random primers with an average of 71.2% polymorphism produced 151 polymorphic bands. Cluster analysis based on these 151 RAPD markers revealed relatively low level (0.434 0.714) of genetic diversity among cultivars and high level of diversity between cultivars and wild relatives. C. albicans and C. lineatus showed only 0.231 similarity with each other and C. albicans showed relatively higher similarity with C. cajan cultivars than that showed by C. lineatus. In dendrogram the 16 cultivars grouped into two distinct clusters comprising of seven and nine genotypes each while the wild species form out groups. Bootstrap analysis of the dendrogram was performed and resulted in significant bootstrap values. Principal components analysis (PCA) also revealed the similar results that of unweighted pair group method with arithmetic mean (UPGMA). The first, second and third PCs contributed 55.9%, 5.9%, and 5.6% of the variation, respectively, with cumulative variation of the first three PCs was 67.4%.