Genetic control of cowpea seed sizes

Abstract

Cowpea [Vigna unguiculata (L.) Walp.] is one of the most widely adapted grain legumes in hot regions of Africa, Asia and the Americas. In the semiarid Northeast of Brazil, it is the main subsistence crop, an excellent protein source of low cost, for the poor population. The objective of this work was to estimate genetic parameters to understand the inheritance of seed sizes in cowpea. The parents P1 and P2 and the generations, F1, F2, BC1 and BC2 of the cross TVx5058-09C X Manteiguinha formed the genetic material for this study. These six generates (P1, P2, F1, F2, BC1 and BC) were evaluated in a completely randomized block-design with six replications, in Teresina - PI, Brazil, in 1998. The genetic parameters estimated were: phenotypic and total genetic variance, additive and dominance genetic components of variance and the variance attributed to the environment, heritability in the broad and narrow senses, average degree of dominance and the number of genes controlling the character. The additive - dominance model fitted the data for 100-seeds weight in as much as the midparental value and the additive effect were the more important genetic parameters for the determination of this character. The number of genes that control its expression is five. The occurrence of high values for narrow sense heritability indicates that the selection for seed size can be made in early generations.

Diallel analysis of cowpea (Vigna unguiculata (L.) Walp.) for some physical properties of seed under the Sudano-guinean conditions

“…The distribution of values of these physical properties for the tested population appeared to be continuous and suggested a quantitative inheritance for these traits. This supports the findings of earlier studies by Drabo et al (1984), Lopes et al (2003) and Noubissié et al (2007). As reported by Lopes et al (2003), Konak et al (2007) seed physical properties are genetically controlled but the implementation of the program is affected by the environmental factors in particular moisture content and temperature (Rahman et al, 2005;Yalcin, 2007).…”

“…Variability for cowpea physical properties was also reported by Drabo et al (1984), Taiwo (1998), Olapade et al (2002), Lopes et al (2003), Kabas et al (2007), Noubissié et al (2007), Yalcin (2007), Ajeigbé et al (2008), Kaptso et al (2008). When the physical properties values obtained in this research were compared with those of previous studies, they were within normal limits.…”

“…Therefore, to produce seed of a specific size, and to meet a specific market demand, a better understanding of the inheritance pattern and gene interactions that govern physical traits is required along with an understanding of potential environmental influence. Variations in cowpea seed physical properties among varieties were found by Drabo et al (1984), Taiwo (1998), Olapade et al (2002), Lopes et al (2003), Unal et al (2006), Kabas et al (2007), Maunde et al (2007), Noubissié et al (2007) and Kaptso et al (2008). Many studies have reported on the physical properties of grains or seeds of plants, such as pea (Gupta et al, 1984;Yalcin et al, 2007), cumin (Singh and Goswami, 1996), bambara groundnuts (Baryeh, 2001), cotton (Ozarslan, 2002;Rahman et al, 2005), sesame (Tunde-Akintunde and Akintunde, 2004), vetch (Yalcin and Ozarslan, 2004), safflower (Baumer et al, 2006), dry beans (Ceyhan, 2006), rice (Thakur and Gupta, 2006) and chickpea (Konak et al, 2002;Hossain et al, 2010).…”

Farmer participation in selection within segregating populations of cowpea in Volta Region, Ghana

“…This shows effectiveness of selection for seed size in early generations of cowpea [16]. Effectiveness in selection in early generations for seed size in chickpea has also been reported [17].…”

Generation Mean Analysis for Yield and Yield Components in Cowpea [Vigna unguiculata (L.) Walp.]

“…The significant opposite signs of dominance and dominance x dominance effects indicated the presence of duplicate epistasis in the inheritance of this trait in cross I, III and IV. Lopes et al, (2003) reported that additive effect was the more important genetic parameter for determination of this character. The involvement of additive and non-additive gene effects suggested that homozygous elite recombinants could be developed following inter-mating of desirable segregants.…”