Inter-relationships in Morphotypes of Greater Yam (Dioscorea alala L.)

Abstract

The germplasm holding in greater yam (Dioscorea alata L.) consisting of 182 accessions belonging to 19 morphotypes
collected from different agro-ecological situations of peninsular India were.subjected to a detailed investigation
on characterization of both above ground and below ground vegetative parts with respect to 49 qualitative and 22
quantitative traits. Seventy-six descriptor states were analyzed for pair-wise similarity coefticients by 'un-weighted
pair-group method analysis (UPGMA) and also for single and complete linkage. The study revealed existence of
9 major arbitrary clusters indicating close resemblances between many of the morphotypes. Clustering pattern did
not show any strict relationship between geographical distribution and morphotypes as the accessions from different
geographic regions and of different morphotypes were grouped in most of the clusters. Based on these observations,
an attempt is being made here to interpret the extent ofsimilarity within and between the earlier described morphotypes