Molecular Characterization of Trichosanthes cucumerina Using SSR Markers

Background and Objective: Trichosanthes cucumerina is a neglected and underutilized vegetable valued by traditional communities for food, yet its genetic diversity remains underexplored in Nigeria. This study aimed to assess the genetic diversity of T. cucumerina accessions from four geopolitical zones in Nigeria using simple sequence repeat (SSR) markers, to generate data useful for gene identification, mapping, and molecular breeding to enhance food security. Materials and Methods: Fourteen-day-old seedlings from fourteen accessions collected across four geopolitical zones were analyzed. Genomic DNA was extracted using the SDS method, and seventeen SSR primers were used for amplification. Banding patterns were scored into a binary matrix and analyzed in Minitab 17. Genetic diversity indices, phylogenetic clustering, Principal Component Analysis (PCA), and Analysis of Molecular Variance (AMOVA) were performed. Results: Major allele frequency ranged from 0.3571-0.8571, allele number from 2.000-4.000, gene diversity from 0.2800-0.7245, and polymorphic information content (PIC) from 0.2800-0.6740. A total of 25 alleles were amplified, averaging two per locus. Three primers (CMTM 34, CMTM 9, LSR 015) showed the highest PIC values. Dendrogram analysis grouped the accessions into three clusters, with PCA explaining 80.61% (PC1) and 7.38% (PC2) of the variation. The AMOVA revealed significant genetic differentiation (p<0.001), with 91% of the variation occurring within accessions and 9% among clusters. Conclusion: The study reveals considerable genetic diversity among T. cucumerina accessions in Nigeria, highlighting specific SSR markers with high discriminatory power. These findings provide essential baseline data for molecular breeding and conservation, contributing to the crop’s potential role in enhancing food security.