Phenotypic variation in cowpea (Vigna unguiculata [L.] Walp.) germplasm collection from Botswana

Abstract

Characterization of cowpea (Vigna unguiculata[Areas not yet explored and those that need additional sampling were identified. The study demonstrated a significant amount of diversity among the germplasm based on the analysis of variance (ANOVA) and Shannon Weaver Diversity Index (H'). The majority of accessions had their first flowering more than 50 days after sowing and 100 days for 95% of maturity which shows that they are more inclined towards late maturing cowpeas. Early maturing accessions with less than 110 days to maturity are found in Ngamiland, Southeast and unknown origin. The accessions from Central districts had the largest variation for most characters (11) followed by Southeast with 10 among the 22 quantitative characters evaluated. Principal components analysis (PCA), revealed characters which discriminated more efficiently between accessions than others such as peduncle length, 10 seeds weight, seed width, seed thickness, pods per peduncle, and 100 seed weight. Cluster analysis delineates germplasm into three clusters, based on the origin of the germplasm according to different agro-ecological zones. Germplasm accessions originating from Ngamiland formed a separate cluster from the rest and had several peculiar materials, which could be a potential source for new germplasm for cowpea improvement. Further molecular studies are required to complement and validate the current agromorphological variation observed in the Botswana cowpea germplasm.

Assessment of variation in the agronomic traits of wild cowpea (Vigna unguiculata (L.) Walp.) subspecies under a rainforest agro-ecology in Nigeria

“…stenophylla flowered around 23 -64 days which confirms non-photosensitive and they may be grouped as early maturing as classified by Singh and Ajeigbe [39] and Dugje et al [40]. In contrast, Molsiwa et al [41] who worked on phenotypic variation in cowpea accessions reported a higher range of 39 -168 days for number of days to first flower. It is important to note that only accession TVNu539 flowered in 3 weeks and produced ripe pods in 4 weeks of planting, making it a potential parent when breeding for early maturity.…”

Variation in seed protein, selected minerals, phytic acid, and potential mineral bioavailability of cowpea [Vigna unguiculata (L.) Walp] mutants and accessions

“…Levels of diversity among cowpea genotypes can be determined through phenotypic characterization and assessment of mineral elements and protein content (Stoilova & Pereira, 2013). Several studies using morphological, agronomic, and nutritional characteristics have evaluated diversity in cowpea populations in South Africa (SA) and International Institute of Tropical Agriculture (IITA; Gerrano et al, 2015Gerrano et al, , 2017Gerrano et al, , 2019Gerrano et al, , 2020Gerrano et al, , 2022Lazaridi et al, 2017;Mbuma et al, 2020Mbuma et al, , 2021Mbuma et al, , 2022Mofokeng et al, 2020;Molosiwa et al, 2016). For years, the Agricultural Research Council (ARC) in SA has been maintaining cowpea germplasm collection of approximately 75 accessions, with genotypes that are either locally bred or derived from other breeding programs.…”

Genetic diversity for immature pod traits in Ethiopian cowpea [Vigna unguiculata (L.) Walp.] landrace collections

“…The analysis of variance revealed significant differences among the genotypes for the ten quantitative characters indicating the presence of adequate variability, which can be exploited through selection. Different reports indicated there is substantial phenotypic variability among cowpea varieties for different characters (Animasaun et al, 2015;Cobbinah et al, 2011;Gerrano et al, 2015;Lazaridi et al, 2017;Menssen et al, 2017;Molosiwa et al, 2016).…”