DNA profiling of banana and plantain cultivars using random amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism (RFLP) markers

Polymerase chain reaction (PCR) amplification of genomic DNA from 57 Musa cultivars with 60 random 10-mer primers generated 605 polymorphic amplification products which were useful in unambiguous cultivar identifications. Unweighted pair-group method analysis of this data grouped the cultivars into specific clusters depending on their genomic similarities. The diploid ancestral species of cultivated banana and plantains, namely Musa acuminata sp malaccensis, an A genome donor and M. balbisiana, a B genome donor, were farthest apart from each other in the phenogram. The edible fruit yielding cultivars with the genomic constitutions AA, AAA, AB, AAB, ABB, and ABBB grouped in different clusters according to overall genetic homologies. The restriction fragment length polymorphisms (RFLPs) prevalent among the cultivars were studied by hybridization of 19 random genomic clones to blots of HindIII, EcoRI and MspI digests. Cluster analysis of these data on 107 polymorphic alleles resulted in a phenogram comparable to the one obtained with random amplified polymorphic DNA (RAPD) analysis. Two multilocus probes useful in distinguishing all the 57 cultivars analyzed were also identified. The A and B types of cytoplasms in the cultivars were further distinguished by hybridization of heterologous chloroplast DNA probes. Results showed that use of different kinds of molecular markers in gene banks is essential for characterization and classification of germplasm collections.