Combining ability and genetic components for pod and seed traits in cowpea lines

Abstract

The identification of suitable parental genotypes potentially generating superior lines with traits contributing to the overall yield of cowpea is an important step in the development of improved varieties. Eight parents and their 28 hybrids obtained through diallel crossing design were evaluated in a randomized complete block design with three replications. Highly significant differences among the parents and their hybrids for different traits were observed. General combining ability (GCA) mean squares were larger than the specific combining ability mean squares for all the traits analysed. The ratio h²/H₂ revealed different number of genes controlling the traits, pointing out their polygenic inherited control. The estimated low narrow sense heritability recorded in this study indicated that recurrent selection procedure could be effective to improve the analysed traits in the genotypes included in this study. <em>Kananado</em> with large, positive and significant GCA effects was identified as the parent with desirable genes for the genetic improvement of the considered yield component in cowpea. In addition, IT03K-316-1 x Cowpea-2 and IT99K-316-2 x Kananado seemed to be the best hybrids for number of pods/plant and 100-seed weight, respectively

Genetic Analysis for Yield and Yield Attributing Traits in Cowpea (Vignaunguiculata L. Walp)

“…Further results showed that none of the parents or specific cross was best for all the characters. Similar results were observed by others (Pandey andSingh, 2010 andAyo-Vaughan et al 2013).…”

“…In contrast, the characters with low narrow sense heritability and lower estimates of the dominance components compared with those of the additive (D), selection may be considerably difficult or virtually impractical due to the masking effect of environments on genotypic effects. Similar result was reported by Ayo-Vaughan et al (2013) in cowpea.…”

Effects of Drought on Morphological Traits in Some Cowpea Genotypes by Evaluating Their Combining Abilities

“…The estimated variances due to specific combining ability were higher than general combining ability indicating the predominance of the nonadditive gene action in these traits in either or both environments. This report is also in agreement with Bhavesh Patel et al [23] and Selvarkumar et al [24], but in contrast to Ayo-Vaughan et al [25]. The estimates of predictability 8 Advances in Agriculture ratio less than unity in these traits suggest that performance of hybrids for these traits could be difficult to predict on the basis of general combining ability of parents due to the importance of dominance.…”

Diallel Analysis and Heritability of Grain Yield, Yield Components, and Maturity Traits in Cowpea (Vigna unguiculata(L.) Walp.)

“…Significant GCA effect is a manifestation of additive and additive × additive gene interactions, which represents a heritable portion of genetic variation which is transmittable from the parent to its progeny [ 15 ]. This therefore could imply that early generation selection would be effective due to small environmental effects [ 16 , 30 ]. The significant negative GCA observed for IT86D-610 and Sanzi-Nya for days to 50% flowering and days to 90% pod maturity also suggests that these parents could contribute favorable alleles for breeding early maturity in cowpea.…”

“…Whereas several studies have been conducted on combining ability for grain yield and yield components in cowpea and other crops [ 16 – 19 ], few studies have been reported on combining ability and heritability of maturity traits and their relationship with grain yield in cowpea [ 16 ]. Early maturity relative to other crops is the unique attribute that makes cowpea one of the most important climate smart crops particularly in areas of short cropping seasons.…”