Molecular Assessment of Genetic Diversity in Cowpea (Vigna unguiculata) Landraces from Borno State Using SSR Markers

Cowpea (Vigna unguiculata) is a nutritionally vital legume crop in the Lake Chad Basin and semi-arid zones of Northeast Nigeria, where diverse traditional landraces have been cultivated across generations. Understanding genetic diversity within these landraces is essential for crop improvement and conservation programs. This study assessed genetic diversity among 30 cowpea landraces collected from farmers in Borno State using simple sequence repeat (SSR) molecular markers. Leaf tissue was used for genomic DNA extraction by the CTAB method. Ten polymorphic SSR primer pairs were employed, with amplification products resolved on 3% agarose gels. Data were analyzed using POPGENE and NTSYSpc software to determine polymorphism information content (PIC), allelic richness, and clustering patterns. A total of 78 alleles were detected across ten loci, with mean PIC of 0.61, indicating moderate to high polymorphism. UPGMA clustering separated the landraces into four major groups that were partially correlated with geographic collection zones. These findings suggest sufficient genetic variation in Borno State cowpea germplasm to support breeding for drought tolerance and yield improvement. Keywords: cowpea, SSR markers, genetic diversity, landraces, Borno State.