Abstract

Amplified fragment length polymorphism was used to study genetic variability and relatedness between African and Asian pigeon pea cultivars. Forty-one samples, 32 African and 9 Asian varieties were subjected to the analyses. The genetic data was subjected to phenetic and analysis of molecular variation (AMOVA). Phenetic analysis revealed no major clusters and indicated limited genetic variability among the samples. AMOVA at continent wide hierarchical level, revealed a significantly weak population structure (F_ST = 0.05, P= 0.001) and Fishers’ exact tests (P<0.05) provided no support for population differentiation. AMOVA based on treating the cultivars as samples from a panmictic population revealed a stronger genetic structure (F_ST = 0.09, P= 0.001). Estimates of average gene diversity were not significantly different among samples but were relatively higher for Indian samples. This study suggests that East Africa pigeon peas are closely related but less genetically diverse than Indian cultivars, which could also serve as source of novel traits for the latter. The study also demonstrated that AFLP is a suitable tool for DNA fingerprinting and genetic studies of pigeon pea.

Key words: AMOVA, Cajanus cajan, genetic diversity, genetic structure.