Genetic variability, association and diversity studies in wheat (Triticum aestivum L.) germplasm

Seventy local and exotic wheat genotypes grown in Faisalabad, Pakistan during the Rabi season of 2005/2006 were evaluated for variability parameters, correlations and path coefficients for eight metric traits i.e., plant height, number of productive tillers per plant, number of spikelets per spike, spike length, number of grains per spike, fertility %, 1000 grain weight and yield per plant. Significant genotypic differences were observed for all the traits studied indicating considerable amount of variation among genotypes for each character. The estimates of genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were high for yield per plant, number of productive tillers per plant and number of grains per spike. The remaining traits recorded moderate to low PCV and GCV estimates. Moderate heritability was observed for number of productive tillers per plant and fertility %. High heritability estimates were recorded for plant height, number of spikelets per spike, spike length, number of grains per spike, 1000 grain weight and yield per plant. These traits also indicated high genetic advance (except fertility %). Grain yield per plant showed highly significant positive correlation with number of productive tillers per plant, number of spikelets per spike and number of grains per spike and significan