WILD EMMER WHEAT IN JORDAN: II. GENETIC DISTANCES BETWEEN AND WITHIN POPULATIONS

Abstract

Evaluation data on 17 morpho-agronomic traits for twelve populations of wild emmer wheat, Triticum dicoccoides, Korn. from central, peripheral, and marginal regions of its distribution in Jordan, were subjected to univariate, principal component, and canonical discriminant analyses. Interrelationships and adjustments in traits under study were used to identify genetic distances and spatial variation among and within these populations. Principal component analysis revealed that the interrelationships implied among traits, in the same principal component, were not the same among and within populations. This spatial variability in principal components reflects specific adaptation to, or interaction with, the environment. Three canonical variables explained 85.0% of total variation in these populations. Spikelet size, flag leaf width, and days to maturity were the most discriminating traits. Mahalanobis distances suggest that spatial distances are not indicative of genetic distances among and within central, peripheral, and marginal populations. A number of trait combinations arising through multilocus genetic association or developmental correlations, which are conserved by genetic linkage and natural selection, are readily available for wheat breeding and improvement.