Genetic variability among wheat genotypes based on Agro-morphological traits under restricted irrigated conditions

Present study was carried out with thirty six promising wheat genotypes to study nature and magnitude of genetic variability and selection strategies to improve the grain yield in wheat using association analyses. Genotypes were evaluated using a randomized complete block design with three replications. Observations were recorded on randomly selected plants for days to 50% heading, days to maturity, plant height (cm), number of tillers/plant, number of ear/plant, number of spikelets/ear, ear length (cm), peduncle length (cm), biological yield/plant (g), grain yield/plant (g), thousand grain weight (g), harvest index (%), relative water content (%), canopy temperature (oC), chlorophyll content index, protein content (%), wet gluten (%) and sedimentation value (ml). Analysis of variance showed sufficient amount of variability in the existing material for all traits studied. Number of ear/plant and ear length showed highest genotypic and phenotypic coefficient of variation. High heritability coupled with high genetic advance was recorded for thousand grain weight and ear length. Among the significant inter-relationships, the plant height showed significant positive association with grain yield/plant and wet gluten; number of tillers/plant with number of ear/ plant, number of spikelet/ear, 1000- grain weight, canopy temperature and sedimentation value; number of tillers/plant with 1000- grain weight, canopy temperature and sedimentation value; number of spikelet/ ear with ear length, chlorophyll content and protein content and ear length with harvest index and chlorophyll content at both phenotypic and the genotypic levels. Whereas, biological yield/plant showed negative significant correlation with 1000- grain weight and grain yield per plant with relative water content. Path coefficient analysis revealed that the magnitude of positive direct effect on grain yield/ plant was highest through harvest index, followed by biological yield/plant and number of tiller/plant; whereas days to maturity, followed by protein content, number of spikelets/ear, number of ear/plant and chlorophyll content exhibited high, but negative direct effect on grain yield per plant, thereby indicated that these were main contributors to the grain yield.