Preliminary study on character associations, phenotypic and genotypic divergence for yield and related quantitative traits among cowpea landraces (Vigna unguiculata) from the Western Highland Region of Cameroon

Abstract

Cowpea (Vigna unguiculata) is an important tropical legume crop contributing significantly to food security in tropical regions. The present study was carried out to determine the extent of genetic variation, to estimate character associations, heritability and genetic advance of 25 quantitative traits in 30 genotypes of cultivated Vigna unguiculata from the western highland region of Cameroon. These quantitative traits were selected among cowpea descriptor lists. For all these traits, the analysis of variance showed significant difference among genotypes, highlighting the existence of important genetic divergence among the studied accessions. The highest phenotypic and genotypic coefficient of variation was observed in grain yield, pod yield and 100 seed weight. Genetic advance of these three characters was also the highest. Broad sense heritability was high in general, with 20 traits out of 25 having heritability values greater than 70%. This high heritability indicates little influence of the environment on these characters in cowpea. The highest heritability was recorded for 100 seed weight (98.15%) and the lowest for shoot weight (41.38%). At 0.05 probability level, grain yield correlated significantly with 21 out of the 24 other quantitative traits. Among others, grain yield correlated positively and significantly with 100 seed weight, number of pods per plant, number of branches per plant, number of nodes per plant, plant height, plant width, pod length, pod width, seed length, seed width and number of seeds per pod. These positive correlations between grain yield and many other traits indicate that a selection program based on any of these traits will result in increasing yield. Cluster analysis using UPGMA method revealed five distinct clusters. Genotypes named KEBCP025, KEB-CP006, KEB-CP098, KEB-CP070, and more importantly KEB-CP054 and KEB-CP004, were grouped in a single cluster and were characterized by a significantly higher grain yield, pod yield, number of pods per plant, number of seed per pod, plant height, pod length and pod width compared to other clusters. Accessions KEB-CP036 and KEB-CP031 produced significantly more important fresh biomass. These genotypes could be used as parents in genetic improvement programs aiming to increase yield and fresh biomass in cowpea.

Estimation of the Variation Coefficient and Some Local Genetical Resources of Some Common Bean

“…Also, there were significant differences between both years of the study, in fruiting measurements, this can be interpreted as this property being affected by the different environmental conditions in two years of the study. Similar results were found by Kouam et al, (2018) and Ghimire et al (2019). They reported that the fruiting measurements of the traits that are affected by the change in environmental conditions.…”

Chemical and molecular examinations of some cowpea genotypes using simple sequence repeat and intersimple sequence repeat DNA markers in relation to their cooking quality

“…Generally, cowpea seeds consumption might be limited owing to the presence of several anti-nutrient factors such as tannins, phytate, and trypsin inhibitors, which reduced their availability (Khalid & Elhardallou, 2016). Soaking process in water before cooking might remove such factors: during soaking, cowpea seeds undergo F I G U R E 3 Electrophoretic banding patterns of ISSR primers produced from the studied cowpea genotypes physiochemical changes leading to softening the seed tissues and hence promoting a shorter cooking time (Hamid et al, 2016;Kouam et al, 2018;Yeung et al, 2009). Moreover, the soaking of cowpea seeds prior to cooking would remove the seed coat pigmentation and polyphenols; also, the content of proteins, sugars, and ash would be affected, which diffuse in the soaking solution.…”

Cowpea Constraints and Breeding in Europe

“…Numerous landraces have been screened for their seed and fresh pod yield performance under adverse environments [ 296 , 330 , 331 , 332 , 333 ]. Among landraces evaluated, some were proved to yield similarly to improved genotypes, such as the “Akidi Ala” local variety from Nigeria and “Chimponogo” local variety from Zambia [ 334 , 335 ].…”