SSR-Based Genetic Diversity and Population Structure Analysis of Selected Okra (Abelmoschus esculentus)

Okra (Abelmoschus esculentus) is the most important cultivated vegetable in Nigeria. It has a low caloric composition with myriads of essential nutrients and minerals needed for daily utilization by the human body. Understanding of genetic diversity and population structure can be used for okra breeding. In the present study, seventeen okra accessions consisting of 15 landraces and 2 commercial varieties were characterized using SSR markers to explore genetic diversity and population structure. In total, 8 SSR markers detected 50 SSR alleles with a mean of 6.25. The highest number of alleles was detected by three primers, namely AVRDC-Okra56 (14), AVRDC-Okra78 (9) and AVRDC-Okra89 (8). The average gene diversity was 0.61 with polymorphic information content ranging from 0.19 to 0.87 and a mean of 0.58. Dendrogram and principal component analysis based on SSR data showed three major groups of the studied okra accessions, revealing substantial genetic variation among the collection. The model-based population STRUCTURE analysis also grouped the accessions into three subpopulations (K = 3) with moderate levels of gene admixture. These findings provide information for future molecular identification of diverse okra varieties and can be used to perform genetic analyses, develop future varieties and implement conservation programs.