Genetic divergence and character association analysis in Pigeonpea [Cajanus cajan (L.) Millspaugh]

Abstract

A field experiment was conducted on pigeonpea [Cajanus cajan (L.) Millspaugh] during kharif season 2009 in Randomized Block Design with three replications at Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut - 250 110 (U.P.). The aim of experiment was to collect the information on genetic variability, direct and indirect selection parameters, path coefficient analysis and genetic divergence for eleven characters viz., days to 50 per cent flowering, days to maturity, plant height, number of primary braches per plant, number of secondary branches per plant, number of pods per plant, pod length, number of "'''..:mbers per pod, number of seeds per pod, 100-seed weight and grain yield per plant by evaluating forty-five diverge genotypes of pigeonpea. The objectives of present investigation were to study the genetic divergence using 0 2 statistics, phenotypic and genotypic variability, path coefficient analysis and character association among the different traits. The systematic data were recorded for above mentioned 11 characters and subjected to different biometrical computations. The results obtained on different aspects for different traits are summarized here as under. ANOVA for the experiment revealed highly significant differences among the genotypes for all the characters under study. Most of the characters showed high percentage of phenotypic and genotypic coefficient of variability. High heritability estimates in broad sense were observed for plant height, days to 5') per cent flowering, days to maturity, 100-grain weight, number of pods per plant, pod length, grain yield per plant, number of primary branches per plant, number of chambers per pc- ~ and number of secondary branches per plant. High genetic advance in per cent of mean was ob~ · '<- :J fo · almost all the characters except pod length, number seeds per pod, days to 50 p '} cent flo. -'··•9 and days to maturity. In the association studies, highly significant and positive correlati "'S were observed for days to 50 per cent flowering with days to maturity, plant height with number ot ods per plant, number of primary branches per plant with number of secondary branches per · 3nt, number of primary branches per plant with number of pods per plant, pod length with num. !r of chambers per pod, number of pods per plant with grain yield per plant and number of chc.mbe .,er pod with number of seeds per pod. Significant and negative association between number of primc:ry br grain weight, number of secondary branches per plant with 100- grain weigh~ ... plant with 100- grain weight, were also observed. ·er plant with 1 00- nber of pods per Path coefficient analysis of grain yield and its contributing charF ··ealed \ra..lt numt.er of pods per plant had the highest positive direct effect on grain yield foi to maturity, 100- grain weight, number of seeds per pod, number of primary branc,er plant ar11. pod length. The direct effects of the remaining characters on grain yield were negati\ e and of low magnitude. The results of 0 2 analysis indicated the presence of high amount of genetic diversity among the genotypes studied. The forty-five genotypes were grouped into eight gene ~.;lusters based on Mahalanobis 02 analysis. The highest inter-cluster distance was observed between cluster VIII and I. whereas, the lowest inter-cluster distance was reflected between clusters VI. and V. The highest intra-cluster distance was expressed by the cluster II and lowest by the cluster V.