Assessment of Genetic Diversity in Plantain (Musa paradisiaca L) Using Yield-Related Agro-Morphological Traits and Microsatellite Markers

Abstract

Background and Objective: Plantain (Musa paradisiaca L) remains one of themost important staple food crop and perhaps, one of the oldest cultivated fruit tree crop in the humid tropics of Africa, Central Asia, South America and the West Indies.Fourteen (14) elite plantain cultivars were evaluated for genetic diversity using agro-morphological yield related attributes and simple sequence repeat (SSR) markers. Materials and Methods: Six (6) microsatellite markers that showed distinct fragments varying from 50 bp to 3.0 Kbp in size of polymorphic bands were selected and used for molecular characterization and fingerprinting, while agro-morphological (yield–related) attributes assessed included bunch weight, number of hands/bunch, number of fingers/hands, number of fingers/bunch, harvest interval, length of plant cycle, pulp hardness and pulp to skin weight ratio of the elite plantain cultivars. Results: The total number of amplified bands (TNB), mean percentage polymorphism (%P), mean polymorphic information content (PIC), average marker index (MI) and mean gene diversity for the SSR assay were 59, 70.24%, 0.79, 3.74 and 0.832 respectively. Results of agro-morphological fingerprint study revealed a significant variations in terms of the bunch weight, number of finger per hands/bunch, number of fingers per hand, number of fingers /bunch, harvest  interval, length of crop cycle, pulp hardness and pulp/wt. ratio all showed significant variations among the cultivars. The distribution of the elite cultivars along with the principal components showed cluster pattern of distribution within the study location. Principal component analysis revealed four principal components contributing 99.91% to the observed morphological variations while analysis of molecular variance revealed 96.00% contributed by molecular characteristics to observed variations. The yield displayed revealed significant contributions of bunch weight, fingers/hand and fingers/bunch as the main indices for plantain yield. The dendrograms for both morphological and molecular characteristics delineated the cultivars into four distinct cluster groups and subgroups each varying in genetic distance. Conclusion: These good cultivars can be exploited for the improvement of low yielding cultivars in other region to increase and improve plantain yield, promote food security and income generation especially under the present economic realities where food security is threatened by the global food crises and declining crop productivity.