1Division of Crop Improvement, Central Potato Research Institute, Shimla-171 001, (H.P.).
2Department of Biosciences, Himachal Pradesh University, Shimla-171 005, (H.P.).
*Part of the Ph.D thesis of Senior author (1998).
Seventeen potato genotypes were studied separately both in the sub-tropical plains and the temperate hills for estimation of genetic divergence using Mahalanobis's D2 statistic. The clustering pattern was different under the sub-tropical and the temperate conditions where the 17 genotypes were grouped into 8 and 6 clusters, respectively. There was very little common with regard to distribution of different genotypes into different clusters under the two conditions. Cluster I was the largest in both the growing conditions. The maximum genetic distance was between cluster II and V and the minimum genetic distance was between cluster VI and VII under sub-tropical conditions, whereas, the maximum genetic distance was between cluster II and VI and the minimum genetic distance was between cluster II and IV under temperate conditions. Intra-cluster distances were lower than the inter-cluster distances and the major contributor to genetic divergence was tuber yield under both the conditions. The genetic diversity was not related to geographic diversity as genotypes originating in different countries were grouped together in the same cluster.
