Genetic control of traits related to maturity in cowpea

Abstract

The aim of this study was to investigate genetic control of the traits number of days to flowering (NDF) and number of days to maturity (NDM) in a cowpea cross. Genetic parameters were estimated in segregating and nonsegregating generations of a cross between two contrasting cowpea genotypes (MNC05-828C-1-9-1 × MNC04-792F-146). No evidence for maternal effect was found for either trait. Broad and narrow sense heritability estimates were above 50%, allowing genetic gains from selection of plants in the F 2 generation. High significance of additive gene effects and low contribution of dominance and epistatic effects were detected for both traits. The estimated number of genes controlling the traits was around 4 for NDF and 5 for NDM. The results suggest that early-maturing cowpea self-fertilized cultivars can be developed through standard breeding approaches, meeting the demands of modern agricultural systems for more crop seasons per year and mechanized harvesting.

Genetic control of earliness in cowpea (Vigna unguiculata (L) Walp)

“…This implies that fewer genes might be controlling earliness in this cross. These results are in agreement with the findings of previous authors who showed that earliness in cowpea is controlled by polygenes (Ishiyaku et al, 2005;Andargie et al, 2014;Ribeiro et al, 2014;Santos et al, 2020). The results however, contradict the monogenic mode of inheritance reported by Yamamoto et al (2016), Owusu et al (2018) and Wang et al (2019).…”

“…These observations are consistent with the results of previous studies in cowpea (Ishiyaku et al, 2005;Yamamoto et al, 2016;Owusu et al, 2018) and in soybean (Bonato and Vello, 1999;Kong et al, 2014). However, the current finding contradicts that of Adeyanju and Ishiyaku (2007); Lo et al (2018) and Santos et al (2020) who noted that inheritance of earliness-related traits in cowpea is controlled by polygenes.…”

“…Flowering time and pod maturity in soybean (a crop, whose genome has homologs and exhibits synteny and colinearity with cowpea (Pottorff et al, 2012;Lucas et al, 2013;Purnamasari et al, 2019) were also found to be controlled by a single dominant gene. Contrary to these reports, Ishiyaku et al (2005) found seven genes controlling DFFA, Ribeiro et al (2014) found three genes controlling DNPM, whereas Santos et al (2020) reported that four and five genes are involved in the genetic control of DFFA and MNPM in cowpea, respectively. Andargie et al (2014) noted that more than one gene and/or a multiple allelic gene system controls the inheritance of flowering time in cowpea.…”

“…According to Gaur et al (2014), number of days to flowering can be recorded with more precision than number of days to maturity, particularly during harsh or long period of unfavorable environmental conditions. Owusu et al (2018) and Santos et al (2020) noted that environmental conditions such as high temperatures have a stronger influence on pod maturation in cowpea than on flowering. This suggests that earliness in cowpea could be controlled by polygenes or largely influenced by the environment.…”

“…Breeding cowpea for improved earliness could help minimize this risk by ensuring that the crops complete their lifecycle before the cessation of rainfall (Owusu et al, 2021). To this end, genetic improvement in earliness has become one of the most important breeding objectives of cowpea breeding programs in SSA (Padi 2007;Santos et al, 2020). Information on the genetic control of key earliness-related traits in cowpea could greatly contribute to the development of extra-early maturing cowpea varieties, which mature in 60 days, to mitigate terminal drought.…”