Genetic Diversity of Cowpea (Vigna unguiculata (L.) Walp.) Accession in Kenya Gene Bank Based on Simple Sequence Repeat Markers

Abstract

Increased agricultural production is an urgent issue. Projected global population is 9 million people by mid of this century. Estimation projects death of 1 million people for lack of food quality (micronutrient deficit) and quantity (protein deficit). Majority of these people will be living in developing countries. Other global challenges include shrinking cultivable lands, salinity, and flooding due to climate changes, new emerging pathogens, and pests. These affect crop production. Furthermore, they are major threats to crop genetic resources and food security. Genetic diversity in cultivated crops indicates gene pool richness. It is the greatest resource for plant breeders to select lines that enhance food security. This study was conducted by Masinde Muliro University to evaluate genetic diversity in 19 cowpea accessions from Kenya national gene bank. Accessions clustered into two major groups. High divergence was observed between accessions from Ethiopia and Australia and those from Western Kenya. Upper Volta accessions were closely related to those from Western Kenya. Low variation was observed between accessions from Eastern and Rift Valley than those from Western and Coastal regions of Kenya. Diversity obtained in this study can further be exploited for the improvement of cowpea in Kenya as a measure of food security.

DArT-seq based SNP analysis of diversity, population structure and linkage disequilibrium among 274 cowpea (Vigna unguiculata L. Walp.) accessions

“…Two to four subgroups with varying levels of genetic diversity were identi ed depending on the germplasm used [17,18,[21][22][23][24][25]. Meanwhile, the reproductive nature of cowpea, which is primarily a self-pollinated plant [6], increases the degree of inbreeding with individuals becoming more homozygous for many alleles, consequently narrow genetic base and genetic distance were reported in the species [23,26]. Furthermore, the high degree of inbreeding in this species also increases chances of linkage disequilibrium (LD) between loci [27], which is a determining factor in marker-trait association analysis [28], hence should be assessed in a plant germplasm collection designated for long-term breeding.…”

Biochemical and molecular characterization of cowpea landraces using seed storage proteins and SRAP marker patterns

“…DNA-based molecular markers have become the tool of choice; they have been widely used in genetic diversity research, variety identification, phylogenetic analysis, gene mapping and resource classification in various crops, including cowpea. Restriction fragment length polymorphism (RFLP) (Fatokun et al, 1993, Ouédraogo et al, 2002), amplified fragment length polymorphism (AFLP), (Kolade et al, 2016, Fang et al, 2007), simple sequence repeat (SSR), (Wamalwa et al, 2016, Asare et al, 2010; Desalegne et al, 2016; Chen et al, 2017), random amplified polymorphic DNA (RAPD) (Udensi et al, 2016, Prasanthi et al, 2012), single nucleotide polymorphisms (SNP) (Muchero et al, 2009, Carvalho et al, 2017), ISSR and start codon targeted (SCoT) (Igwe et al, 2017) have been used in cowpea genetic and breeding studies.…”

Developing a rapid and highly efficient cowpea regeneration and transformation system using embryonic axis explants

“…Despite its high tolerance to heat, dry conditions and soil acidity, cowpea is highly susceptible to insect pest and pathogen infestations resulting in lower productivity (Abdu Sani et al, 2015;Boukar et al, 2016;Obembe, 2008;Singh, 2014;Solleti et al, 2008a). Due to limited genetic variability of cowpea and strong crossincompatibility between wild Vigna species and cultivated cowpea, little progress has been made in genetic improvement through conventional breeding to achieve desirable agronomic traits (Abdu Sani et al, 2015;Fang et al, 2007;Gomathinayagam et al, 1998;Latunde-Dada, 1990;Wamalwa et al, 2016). Hence, plant biotechnology provides an alternative approach to overcome those production constraints for improving the agronomic performance and developing better cowpea cultivars with higher grain quality and yield (Carlos Popelka et al, 2004;Zaidi et al, 2005).…”