Genetic diversity among INERA-Mulungu (DR Congo) Musa spp. germplasm and their relatedness to those in Tanzania using numerical taxonomy

Abstract

Bananas and plantains (Musa spp.) constitute staple food for over 20 million people in Democratic Republic of Congo (DRC). Since 1960, DRC is considered as a secondary centre of plantain diversification with few unknown accessions kept in the INERA-Mulungu genebank. Through similarity coefficients, cluster (unweighted pair group method with arithmetic mean, single, complete, sequential, agglomerative, hierarchical and nested design/clustering procedure) and/or multivariate analyses, numerical morpho-taxonomy has established that this diversity is composed of 37 different accessions. Each accession expressed 98 characters among the 401 possible character states, thus providing 39,298 feature patterns (data points). The 98 characters included 32 vegetative and 66 male and female inflorescences. The accessions were clustered into three genomic groups (AAA, AAB and AABB). Subjective classification ascertained nine subgroups: AAB-Silk, AAB-Pome, AAB-Plantain, AABB-Pisang Awak, AAA-Cavendish, AAA-Ibota, AAA-Gros Michel, AAA-Green-Red and AAA-Lujugira-Mutika. Three subgroups were further divided into nine clone sets which consisted of: Dwarf and Giant Cavendish, French and Horn Plantains, and Musakala, Nfuuka, Nakitembe, Nakabululu and Beer/Mbidde within Lujugira-Mutika. Numerical morpho-taxonomy effectively indicated a relationship between the DRC and Tanzania's Musa diversity. For example, the accessions ‘Kamaramasengi’ and ‘Isangi’ were found to be similar to ‘Kisukari’ (AAB-Silk) and ‘Ngego I’ (AAB-French) common in the Tanzanian Southern Highland. Likewise, the accessions Kimalindi-fupi, Kimalindi-ndefu and Jamaica of Tanzania were duplicates of Bakurura (Kigurube), Cavendish of Butuza and Gros Michel in DRC, respectively. Moreover, numerical morpho-taxonomy confirmed the pedigree of AAB-Prata (Cibwalo) in FHIA 17 and FHIA 23 and the closeness of the ancestors of Yangambi Km5 and Gros Michel. Furthermore, numerical morpho-taxonomy established AA-Mshale malembo as one of the AAA-Lujugira-Mutika parents. Molecular investigations are finally required to confirm the genomes.