GENETIC DIVERSITY OF BANANA AND PLANTAINS ON FARMERS' FIELDS IN THE NIGER DELTA REGION OF NIGERIA

The Niger Delta region of Nigeria, a hub for smallholder banana (Musa spp.) and plantain cultivation, faces genetic erosion due to urbanization, oil pollution, and climate change. This study provides the first comprehensive assessment of on-farm genetic diversity in the region using 12 microsatellite (SSR) markers and morphological traits from 180 accessions across 90 farms. Results revealed high genetic diversity (He = 0.69), with 70% of variation residing within farms, underscoring the role of farmer-led sucker exchange networks. Bayesian clustering identified three genetic clusters: AAB plantains in Delta State (65% ancestry), ABB cooking bananas in Rivers State (58%), and admixed genotypes in Bayelsa (42% Cluster 1, 38% Cluster 2). Moderate differentiation among states (Fst = 0.18, p < 0.001) reflected agroecological adaptations, while morphological traits like bunch weight (18.5 ± 3.2 kg in AAB) correlated with genomic groups. Farmer practices, including regulated suckering (65% in Bayelsa) and drought-tolerance selection, significantly shaped genetic structure. The absence of isolation-by-distance (r = 0.15, p = 0.14) confirmed sucker exchange overrides geographical barriers. This study highlights the Niger Delta as a Musa diversity hotspot, urging ex situ conservation of Delta's AAB plantains and ABB genotypes for breeding climate-resilient hybrids. Policy integration of genetic data into Nigeria's agricultural frameworks is critical to mitigate genetic erosion.