Genetic variability and correlation studies in sweet potato (Ipomoea batatas Lam. L.)

Abstract

Genetic variability and correlation coefficients were worked out for eight parameters in 86 genotypes of sweetpotato (Ipomoea batatas Lam) of diverse origin. For all the characters studied, phenotypic coefficient of variation (PCV) was higher than the genotypic coefficient of variation (GCV) indicating the influence of environment on the expression of these traits. The characters viz. number of branches per plant, weight of single tuber, girth of tuber and length of tuber showed higher estimates of PCV and GCV. High heritability estimates were noticed for vine traits viz. length of vine, number of branches per plant and weight of foliage per plant. The least estimate of heritability was observed for number of tubers per plant. The characters such as number of branches per plant, weight of single tuber, girth of tuber and length of tuber showed high heritability estimates associated with high genetic advance indicating the presence of additive gene effect. Characters like weight of single tuber, girth of tuber, length of tuber and number of branches per plant showed a strong positive correlation with tuber yield. However, length of vine expressed a strong negative correlation with it. Selection based on weight of single tuber, length of tuber and number of branches. per plant can be effective for genetic improvement of sweet potato.