Analysis of Genetic Diversity in Wheat (Triticum Aestivum L.)

Abstract

Analysis of Genetic Diversity in Wheat (Triticum aestivum L.)" involving 49 genotypes was undertaken to study the genetic variability, heritability, genetic advance, correlation coefficient, path coefficient analysis and genetic divergence. The characters under study were days to 50% flowering, plant height, peduncle length, number of productive tillers per plant, days to maturity, spike length, number of spikelets per spike, number of grains per spike, I 000-grain weight, biological yield per plant, grain yield per plant, harvest index and gluten content. The analysis of variance revealed significant differences among the genotypes for all the characters studied. High estimates of genotypic coefficients of variability were observed for grain yield per plant, followed by plant height, I 000-grain weight, number of spikelets per spike and number of grains per spike; moderate GCV (%) was observed for biological yield per plant, followed by spike length, number of productive tillers per plant, gluten content and harvest index while low GCV (%)was observed for days to 50% flowering followed by days to maturity and peduncle length. The heritability estimates varied from 17.00% to 94.80%. Very high estimates of heritability were found for the characters like grain yield per plant followed by biological yield per plant. number of grains per spike, number of spikelets per spike, days to 50% flowering, plant height, peduncle length, harvest index and 1000-grain weight. Highest genetic advance in percent of mean was observed for number of grains per spike followed by number of spikelets per spike, plant height, and spike length, grain yield per plant and I 000-grain weight. The grain yield per plant had positive and significant association with spike length followed by I 000-grain weight, number of productive tillers per plant, harvest index, biological yield per plant and plant height both at genotypic and phenotypic levels. Biological yield per plant had the highest direct effect and genotypic correlation with grain yield followed by harvest index. The 49 genotypes were grouped into 8 clusters. The intra-cluster distance ranged from 0.08 to 30.06. The maximum inter-cluster distance was observed between cluster VII and Vlll, suggesting the hybridization possibilities between the genotypes by virtue of their wide genetic diversity. Consequent upon the present investigation on genetic variability, heritability, genetic advance, correlation and path analysis suggested that the genotypes taken for the present study were having high range of genetic variability which may be used in hybridization programme for obtaining superior and desired gene recombinants for particular character. Both the direct and indirect selection parameters were found pote~tial for improving the traits of interest through selection breeding programme. On the basis of studtes made on genetic divergence, it was suggested that the crosses between the genotypes of cluster IV, and V may give fruitful results in hybridization programme.