Genetic Diversity, Conservation and Improvement of Gongronema latifolium Benth., in South-Eastern Nigeria Using the Internal Transcribed Spacer – ITS

Gongronema latifolium Benth., is listed among the important vegetable with medicinal attributes. Its native habitat currently threatened in Nigeria and there is death of molecular genetic information important for breeding and conservation purposes. To study the species genetic diversity, 50 accessions were collected from South Eastern Nigeria where the species is endemic and was subjected to molecular evaluation using the non-coding internal transcribed spacer (ITS 4 and 5) location. Relatively high within population gene diversity and low nucleotide (base) diversity was identified among the fifty (50) accessions. AMOVA analysis highlighted 93% within population diversity (variations). FST = 0.074 genetic differentiation was recorded for genetic diversity. Principle component analysis (PCA) segregated the accessions into four large groups (A-D), along non-geographical lines; with four outliers' accessions; AwkCH051 (Akwa Ibom), EnuCH014 (Enugu), EboCH036 and EboCH037 (Ebonyi). Expectedly, the species recorded low-moderate genetic diversity common for organisms experiencing decreasing cover range. Enugu recorded the least within population diversity and Ebonyi showed higher diversity than states and might constitute the core of a possible genetic centre for the species. The outlier accessions represent potential parental lines for breeding and improvement programmes. Conservation efforts comprising in situ and ex situ strategies are required to arrest the declining diversity of the species in its native range across Southern Nigeria. Conservation and improvement efforts will sustain the uses of the plants, reduce poverty and improve the livelihood of gatherers, farmers and vendors of the plant, who are particularly women in the region.