Title : Molecular screening of stored cowpea (Vigna unguiculata (L.) Walp.) genotypes using DArTseq (GBS) derived SNPs
Mr Goitsemang Dikane is currently a Masters student at the Agricultural Research Council-Grain Crop and Central University of Technology, South Africa. He progresses in Plant breeding working on Cowpea. In 2019 he was a provincial FameLab science communications winner against provincial universities. Moreover, he won the best poster presenter at the South African Plant breeding Association. He’s still an entry young scientist breaking through the walls.
Cowpea (Vigna unguiculata (L.) Walp) is the credible constituents of nutritious food and forage in humans and animals since the Neolithic area. It is rich in proteins, vitamins and minerals serving as animal protein substitute in under-nourished countries. Molecular screening informs diversity and selection of heterogeneous parents in breeding programmes. The study aimed to screen 92 cowpea genotypes stored in the Agricultural Research Council-Grain Crops germplasm bank, for genetic diversity, profiling and breeding programmes. DNA was extracted using the CTAB protocol, genotyped using DArTseq (GBS) and analysed using DArTsoft14. A total of 33920 DArTseq derived SNPs were recalled for filtering, resulting in 16960 informative SNPs. The R studio (R software version 3.4) was used to compute informative SNPs to generate UPGMA dendrogram, PCA, Gene diversity table, and hierarchical heatmap. The polymorphic information content (PIC) mean value of the overall genotypes was 0.35, with genetic diversity (He) mean value of 0.35. The average major allele frequency (MAF) was 0.73, with observed heterozygosity (Ho) mean value of 0.39. The inbreeding coefficient was -0.113.The dendogram clustered genotypes into three main groups. The divergent genotypes recorded were TVU 9596 (SB26), Orelu (SB72), 90K-284-2 (SB55), RV 403 (SB17), and RV 498 (SB16). The results validated genetic diversity among selected genotypes. Moreover, DArTseq proved to be the best tool for molecular screening to ascertain biodiversity of the collected germplasm. The findings will also guide future breeding projects for crop improvement