Studies on Genetic Associations, Variability and Diversity in Pearl Millet (Pennisetum glaucum (L.) R. Br.)

Abstract

The experiment was conducted among 20 genetically diverse pearl millet genotypes in randomized block experimental design with three replications at Agricultural Research Station, Bikaner (India) in 2011 for evaluating genetic associations among physiological and morphological attributes and their direct and indirect influence on the grain yield of pearl millet. Data revealed highly significant differences among the genotypes for physiological and morphological traits such as relative water content (%), total chlorophyll content, rate of photosynthesis, transpiration, stomatal conductance, internal CO concentration, leaf temperature, plant height, number of productive tillers per plant, panicle diameter, panicle length, test weight, dry fodder yield, grain yield and harvest index. The genotypic and phenotypic coefficients of variation were similar for all the traits. High heritability coupled with high genetic advance as percentage of mean was observed ranging from 63.90% to 86.10% for all traits that were significantly different among the genotypes except relative water content, total chlorophyll content, transpiration rate, internal CO concentration and leaf temperature, suggesting the presence of additive gene action and possibility of improving these characters through selection. Based on character association and path analysis, it is concluded that total chlorophyll content, test weight, dry fodder yield and harvest index were the most important component characters for the grain yield. On the basis of multivariate analysis, 20 genotypes were grouped into 5 clusters. This suggested the presence of high degree of divergence in the material studied. These clusters may provide promising genotypes for further improvement for the respective characters. Based on per se performance, PB-106 and HHB-197 were observed outstanding due to their high mean value of test weight, grain yield per plot, productive tillers per plant and panicle diameter and therefore, could be used as a reference variety for further breeding programme.