Assessment of genetic diversity of Vigna unguiculata (L.) Walp (cowpea) accessions using informative molecular markers is imperative for their genetic improvement and conservation. Use of efficacious molecular markers to obtain the required knowledge of the genetic diversity within the local and regional germplasm collections can enhance the overall effectiveness of cowpea improvement programs, hence, the comparative assessment of Inter-simple sequence repeat (ISSR) and Start codon targeted (SCoT) markers in genetic diversity of V. unguiculata accessions from different regions in Nigeria. Comparative analysis of the genetic diversity of eighteen accessions from different locations in Nigeria was investigated using ISSR and SCoT markers. DNA extraction was done using Zymogen Kit according to its manufacturer’s instructions followed by amplifications with ISSR and SCoT and agarose gel electrophoresis. The reproducible bands were scored for analyses of dendrograms, principal component analysis, genetic diversity, allele frequency, polymorphic information content, and population structure. Both ISSR and SCoT markers resolved the accessions into five major clusters based on dendrogram and principal component analyses. Alleles of 32 and 52 were obtained with ISSR and SCoT, respectively. Numbers of alleles, gene diversity and polymorphic information content detected with ISSR were 9.4000, 0.7358 and 0.7192, while SCoT yielded 11.1667, 0.8158 and 0.8009, respectively. Polymorphic loci were 70 and 80 in ISSR and SCoT, respectively. Both markers produced high polymorphism (94.44–100%). The ranges of effective number of alleles (Ne) were 1.2887 ± 0.1797–1.7831 ± 0.2944 and 1.7416 ± 0.0776–1.9181 ± 0.2426 in ISSR and SCoT, respectively. The Nei’s genetic diversity (H) ranged from 0.2112 ± 0.0600–0.4335 ± 0.1371 and 0.4111 ± 0.0226–0.4778 ± 0.1168 in ISSR and SCoT, respectively. Shannon’s information index (I) from ISSR and SCoT were 0.3583 ± 0.0639–0.6237 ± 0.1759 and 0.5911 ± 0.0233–0.6706 ± 0.1604. Total gene diversity (Ht), gene diversity within population (Hs), coefficient of gene differentiation (Gst) and level of gene flow (Nm) revealed by ISSR were 0.4498, 0.3203, 0.2878 and 1.2371 respectively, while SCoT had 0.4808, 0.4522, 0.0594 and 7.9245. Both markers showed highest genetic diversity in accessions from Ebonyi. Our study demonstrated that SCoT markers were more efficient than ISSR for genetic diversity studies in V. unguiculata and can be integrated in the exploration of their genetic diversity for improvement and germplasm utilization.

Sustainable agricultural productivity is hampered by over-dependency on major staple crops, neglect and underutilization of others, climate change, as well as land deterioration. Challenges posed by these limiting factors are undoubtedly contributing to global food insecurity, increased rural poverty, and malnutrition in the less developed countries. Miscellaneous neglected and underutilized grain legumes (MNUGLs) are crops primarily characterized by inherent features and capabilities to withstand the effects of abiotic stress and climate change, significantly replenish the soil, as well as boost food and protein security. This chapter provides insight into the benefits of MNUGLs as food and nutritional security climate smart crops, capable of growing on marginal lands. Exploring and improving MNUGLs depend on a number of factors among which are concerted research efforts, cultivation and production, as well as utilization awareness across global populace geared toward reawakening the interest on the abandoned legumes. The emergence of the clustered regularly interspaced short palindromic repeat (CRISPR/cas9) technology combined with marker-assisted selection (MAS) offers great opportunities to improve MNUGLs for sustainable utilization. Advances in improvement of MNUGLs using omic technologies and the prospects for their genetic modification were highlighted and discussed.

The genetic diversity of 40 African yam bean (AYB) accessions was assessed using amplified fragment length polymorphism (AFLP) markers. Seeds of 40 accessions of AYB obtained from the International Institute of Tropical Agriculture (IITA) and Institute of Agricultural Research and Training (IAR&T) Ibadan, Nigeria, were grown in a greenhouse and young leaves from two weeks old plants collected for DNA extraction. The four primer combinations used generated a total of 1730 amplification fragments across the AYB accessions used in this study of which 1647 were polymorphic (95.20%). The number of amplified polymorphic AFLP bands per primer pair varied from 360 to 520 with an average percentage polymorphism of 95.6%. E-AGC/M-CAG produced the highest number of polymorphic bands (520). Polymorphic information content (PIC) values ranged from 0.9447 to 0.9626. The highest level of polymorphism (100%) was recorded for two primer combinations (E-AAC/M-CAG and E-ACT/M-CAG). The results of cluster analysis using UPGMA tree, grouped the 40 accessions of AYB into two major clusters with an overall similarity of 67.5%. The level of similarity between the accessions spanned 0.66 to 0.91. TSs 138 and TSs 139 were the most closely related accessions with high level of similarity index (0.91). Comparable results were obtained using Factorial Coordinate Analysis (FCO). The results from the present study confirm the robustness and the suitability of the AFLP as a molecular tool for the assessment of genetic diversity in AYB accessions. Key words: Amplified fragment length polymorphism (AFLP), cluster analysis, genetic diversity, Sphenostylis stenocarpa, polymorphism.

Wheat production in Zimbabwe is strongly influenced by environmental variability, making it difficult for breeders to identify genotypes that are both high yielding and stable across locations. This study evaluated the yield performance and stability of pre-release bread wheat genotypes across contrasting environments in Zimbabwe. A total of 25 genotypes in 2020 and 24 genotypes in 2021 were tested using a randomized complete block design (RCBD) with three replications at three sites Gwebi Variety Testing Centre (GVTC), Harare Research Station (DR&SS), and Panmure, forming six test environments across two winter seasons. Grain yield and key agronomic traits were recorded and analyzed using combined analysis of variance, correlation analysis, and genotype plus genotype-by-environment (GGE) biplot methods. The combined analysis of variance revealed highly significant (p < 0.001) effects of location on all traits in both years, confirming strong environmental influence on wheat performance. Genotypic differences were also significant for most traits in each season. In 2020, genotype × location interaction for grain yield and grain weight was not significant, indicating relatively stable genotype ranking across environments. In contrast, significant genotype × location interaction in 2021 demonstrated strong crossover effects, with genotypes responding differently across sites. When the 15 genotypes common to both years were analyzed together, genotype × location interaction for grain yield was again not significant, indicating that this subset of genotypes expressed greater yield stability across environments. GGE biplot analysis revealed clear differences in genotype adaptation and stability. The mean versus stability view identified G10 and G4 as high yielding with moderate stability, while G5 and G8 were closest to the ideal genotype, combining high yield and wide adaptation. The which-won-where pattern separated the test environments into two main mega-environments, with G3 and G10 performing best in GVTC- and Harare-based environments, while G4, G5, and G8 were superior at Panmure-related environments. Environment E3 (Harare 2020) was identified as the most representative and closest to an ideal test environment, while E1, E2, E5, and E6 were more discriminating and useful for detecting genotype differences. The findings of this study demonstrated that both yield level and stability must be considered when selecting wheat genotypes for Zimbabwe. Genotypes G5 and G8 showed the best combination of high grain yield and stability and are therefore recommended for broad adaptation. Genotypes such as G3 showed high yield but strong environmental sensitivity and are better suited for specific environments. These findings provide valuable guidance for wheat breeding and variety recommendation in Zimbabwe’s diverse production environments.