Assessment of Genetic Diversity of Cowpea Germplasm based on Morphological Characters

Abstract

Cowpea is a grain legume well adapted for low input agriculture systems in subsistence farming. Development of suitable cowpea varieties with better yield attributes will be beneficial for the cowpea growing farmers. Diversity of the germplasm collection is critical for selecting parents for the hybridization program in crop improvement with higher yield potential and wide adaptability. Sixty one cowpea accessions received from Plant Genetic Resource Centre, Gannoruwa, Sri Lanka, were evaluated with three released varieties in three rows lines during 2010 Yala season. Lines were assessed for twenty one morphological characters based on the cowpea descriptor of Plant Genetic Resource Centre of the Department of Agriculture. Hierarchical cluster analysis followed by K - mean cluster analysis based on principal components of morphological characters reviled that there was a considerable amount of variation to be exploited in cowpea breeding program. Pod length, ten seed length, ten seed width and days to flowering showed considerable variation among the tested accessions. The recommended varieties Dhawala, MI 35 and Bombay were clustered together between 5-10 Euclidian distance while two m ajor clusters were joint at 20-25 Euclidian distance.