Genetic base and diversity in groundnut genotypes

For the last four decades, genetic improvement of groundnut by induced mutation and recombination breeding at the Bhabha Atomic Research Centre, Trombay, Mumbai, India, has led to the isolation of 61 distinct genotypes, of which eight have been released for commercial cultivation. The present study was undertaken to quantify the genetic base and study the diversity through coefficient of parentage and cluster analysis. Eight ancestors have contributed to the entire genetic base, and of these 'Spanish Improved', through its induced mutants and mutant derivatives, accounts for 67.7% coefficient of parentage, leading to a narrow genetic base. However, the genotypes used in this study exhibited considerable variability for vegetative, reproductive and agronomic traits. Cluster analysis indicated no relationship between clustering pattern and subspecies among genotypes during rainy or summer seasons. Despite this narrow base, greater diversity could be possible following judicious use of mutation and recombination breeding to bring about genetic improvement.