Inheritance of Early Maturity in Some Cowpea (Vigna unguiculata (L.) Walp.) Genotypes under Rain Fed Conditions in Northern Ghana

Abstract

A field experiment was conducted at Savanna Agricultural Research Institute in 2015 cropping season to examine the inheritance of early maturity among an extra-early maturing landrace Sanzi and a medium maturing variety Padi-Tuya and their progenies. The results indicated highly significant (P<0.01) genetic variations for the maturity indices, namely, days to first flower initiation (DFFI), days to 50% flowering (DFF), days to first pod maturity (DFPM), days to 90% pod maturity (DNPM), and plant height (P_PLT), seed per pod (S_Pod), and hundred seed weight (H_SWT). Heritability estimates for these traits varied from 74% to 99%. No significant differences (P>0.05) were observed between F1 and RF1, implying absence of maternal effect. The segregation ratio in the F2 population for early and medium maturity fitted into the ratio 3 : 1, indicating single dominant gene mode of inheritance. Significant positive correlations were found between DNPM, DFFI, DFF, and DFPM; hence selection criteria to improve early maturity of cowpea should focus on these traits. Grain yield also had significant positive correlations with maturity indices indicating high grain yield is associated with late maturity; therefore, high grain yield should be considered alongside early maturity when selecting progenies for earliness.

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

“…High broad-sense heritability observed for number of days to 50% flowering (87.95%) and days to 90% pod maturity (89.22) indicates that additive or genetic factors influenced the expression of the traits and that the traits were less influenced by environmental factors. Similar results have been reported by [ 31 ]. The high broad-sense heritability estimates mean that the phenotypes were true reflection of the genotypes for the measured traits and that selection based on the phenotypic value could be reliable.…”

“…Similarly, IT86D-610 and Sanzi-Nya are good general combiners and sources of genes for early and extra-early maturity in cowpea, respectively. Negative GCA for days to 50% flowering and days to 90% maturity are indication of favorable dominant or partial dominant alleles, which contribute to earliness [20,31].…”

“…Similarly, IT86D-610 and Sanzi-Nya are good general combiners and sources of genes for early and extra-early maturity in cowpea, respectively. Negative GCA for days to 50% flowering and days to 90% maturity are indication of favorable dominant or partial dominant alleles, which contribute to earliness [ 20 , 31 ]. Therefore, breeding methods such as pedigree selection, marker assisted backcrossing, recurrent selection, or marker assisted selection could be used in effective introgression earliness gene in Sanzi-Nya into elite varieties [ 32 ].…”

“…Moreover, high heritability in the narrow-sense relates to high genetic potential, low environmental influence, and good genetic variability for effective selection of the traits. The results suggest that early generation selection will be effective for the traits [ 31 ]. Therefore, selection based on phenotypic value would be a true reflection of the breeding value.…”

Epistasis Detection and Modeling for Genomic Selection in Cowpea (Vigna unguiculata L. Walp.)

“…Pleiotropic QTL between MAT and FLT were also reported in soybean (Kong et al, 2018). This suggest a possible genetic basis for the positive relationship found between MAT and FLT in prior studies (Huynh et al, 2018; Owusu et al, 2018). A major large effect locus explaining up to 29% of the phenotypic variation was found to be associated with SS.…”