Correlation among Agronomic Characteristics and Their Contribution for the Yield Improvement in F4 Generation of Cowpea ( Vigna unguiculata (L). Walp)

Abstract

Estimation of correlation among yield and yield related characteristics at segregating population levels is important in indirect selection process of plant breeding. Hence, segregating populations of two cowpea [Vigna unguiculata (L) Walp] crosses CP 19 x Waruni and CP 20 x CP 22, were assessed using three breeding methods namely, pedigree, Single Seed Descent (SSD) and modified bulk. Six F2 populations were maintained for two cowpea crosses with respect to three breeding methods during 2011 yala season and F3 and F4 populations for each method were established during 2012/12 Maher and 2012 Yala seasons, respectively. Data were recorded on plant height at maturity, number of peduncles per plant, number of pods per plant, number of seeds per pod, average length of pod, hundred seed weight and yield per plant in F4 generation. According to Pearson correlation analysis positive phenotypic correlations were recorded between the seed yield per plant and pods per plant, peduncle per plant and hundred seed weight. Pods per plants was correlated with yield in pedigree method for cross 01 and cross 02 by 0.745 and 0.611 and 0.612 and 0.817 (p <0.01] for bulk method, respectively. Stepwise multiple regressions also revealed that pods per plant, hundred seed weight and pod length as contributing factors for seed yield per plant Equation for SSD method in cross 01 (Y = - 23.8995 + 1.142X2 - 0.592 X4 +1.0513Xs + 1.21X6] was included four contributing characters. Therefore pods per plant, hundred seed weight and pod length could be effectively used as selection criteria for yield improvement in cowpea breeding.