GENETIC VARIABILITY, CHARACTER ASSOCIATION AND DIVERSITY ANALYSIS IN WHEAT (Triticum aestivum L.)

Abstract

Current research work was a modest attempt to screen out suitable parental group from twenty wheat genotypes with better performance and heritable characters. In this regard, twenty wheat genotypes were collected from BARI and ten characters viz. plant height, spikes/plant, spike length, grains/spike, 1000-grain weight, harvest index, vegetative period, grain filling period, days to maturity and grain yield/plant were selected for investigation. Significant variations were observed among the genotypes for all the characters studied. Most of the characters had shown slightly higher phenotypic coefficient of variation than corresponding genotypic coefficient of variation but spikes/plant had shown wide gap which suggested greater environmental influence in controlling this trait. Harvest index and grain yield/plant had shown high heritability with high genetic advance indicated additive gene action in controlling this trait and heritable in nature. Spikes/plant had shown low heritability with low genetic advance indicating that it was controlled by non-additive gene. Correlation coefficient analysis had shown that genotypic correlation co-efficient was slightly higher than the corresponding phenotypic correlation co-efficient for most of the characters except for grain filling period. Grain yield/plant had shown highly significant and positive correlation with harvest index, spike length, 1000-grain weight and grains/spike. Path coefficient analysis also confirmed that these characters had influenced grain yield directly in positive direction. So, these characters should be taken into consideration in selection for yield improvement. Multivariate techniques were used for diversity analysis. Twenty wheat genotypes were clustered into five diverse groups. The maximum number of genotypes were grouped in cluster I followed by cluster V, IV, III and II. The highest inter cluster distance was noticed between the clusters I and II. Therefore, the genotype G12 (BARI Gom 22) for longest spike length and highest percentage of harvest index from cluster III, G15 (BARI Gom 25) for maximum 1000-grain weight from cluster III, G6 (Akbar) for shorter vegetative period from cluster II and G10 (BARI Gom 20) for shorter grain filling period from cluster V could be selected for future hybridization program.