Mahalanobis generalized distance and genetic diversity in sorghum

Eighty nine sorghum genotypes including 70 hybrids resulting from line (5) x tester (14) mating and their 19 parents were classified using D² statistic into nine clusters. A comparison of the culturing pattern of parents vis-a-vis their hybrids, the magnitude of heterosis in crosses involving parents in the same cluster with those in different clusters and the D² values between parents with heterosis exhibited in their cross combinations revealed absence of any relationship between topological distance and genetic diversity. D² statistic might be useful in discriminating materials having high divergence for the factors important for fitness. However, under intense human selection the situation is too complex for being handled by multivariate analysis alone.