Comparative study of molecular and morphological methods for investigating genetic relationships among Bvumbwe Agricultural Research Station field gene bank banana cultivars

Morphological characterisation of bananas has contributed considerably to the body of knowledge of present banana taxonomy. However, the influence of the environment on plant morphology necessitates the use of genetic characterisation to validate taxonomic classifications based on phenotypic traits. This study compared the use of microsatellite markers and morphological traits in estimating genetic relationships among banana cultivars. A total of 12 gene bank cultivars were characterised morphologically using 109 descriptors and genetically utilising 12 microsatellite loci. The two data sets were not analogous as revealed by Mantel's distance matrices comparison test (r=0.063, p=0.695), probably because genetic radiation detected by molecular markers is not necessarily reflected in morphological variables measured. However, cluster analysis of morphological and microsatellite data revealed two distinct subgroups of Nakashuga(AA)-Phwiza(AA)-Ngelezi(AA) and Zomba green(AAA)-Zomba red(AAA) which were analogous indicating that the two techniques can compliment each other. Ngelezi (AA), Nakashuga (AA) and Phwiza (AA) were confirmed by both methods as possible synonyms and somatic mutants.