1736 K. V. Bhat, R. zyxwvutsrqponmlk L. Jarret and R. S. Rana zyxwvutsrqpo Electrophoresis 1995, zyx 16, 1136-1745 K. Venkataramana Bhat' Robert L. Janet' Rai Singh Rana' DNA profiling of banana and plantain cultivars using random amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism (RFLP) 'National Bureau of Plant Genetic 'USDA/ARS, Georgia Experiment Resources, New Delhi markers Station, Griffin, GA Polymerase chain reaction (PCR) amplification of genomic DNA from 57 zy Musa cultivars with 60 random 10-mer primers generated 605 polymorphic amplification products which were useful in unambiguous cultivar identifica- tions. Unweighted pair-group method analysis of this data grouped the culti- vars into specific clusters depending on their genomic similarities. The diploid ancestral species of cultivated banana and plantains, namely Musa acuminata ssp malaccensis, an A genome donor and M. balbisiana, a B genome donor, were farthest apart from each other in the phenogram. The edible fruit yiel- ding cultivars with the genomic constitutions AA, A M , 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 hybridizations of 19 random genomic clones to blots of HindIII, EcoRI and MspI digests. Cluster analysis of these data on 107 poly- morphic 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 char- acterization and classification of germplasm collections. 1 Introduction Bananas and plantain are an important source of calories and essential nutrients [l] for the peoples of Asia and Africa. The banana is one of the major dessert fruits in Europe and the Americas. In spite of the importance of the banana in trade and commerce, very little is known of the genetics of its agronomically important traits [2]. The phenomenon of parthenocarpy along with female genic sterility and structural hybridity [3] have made banana breeding a tough task. Therefore, banana cultiva- tion has been dependent largely on the naturally occur- ring variants selected by farmers. The cultivated forms of banana and plantain include M. acuminata (A genome) diploids and triploids, and their hybrid forms with M. balbisiana (B genome). The hybrid forms of cultivars belong to AB, AAB, ABB and ABBB genomic groups [4]. Areas of diversity for wild species of Musa and the culti- vars span from India to Japan and Samoa [l]. Germ- plasm collection, characterization and conservation are important prerequisites for their utilization in crop improvement programs. Musa germplasm comprises few wild species and a large number of cultivars. The culti- vars are agronomically tested, having been in cultivation Correspondence: Dr. K. V. Bhat, National Bureau of Plant Genetic Resources, Pusa Campus, New Delhi-110012, India (Tel: +91-11-573- 9565; Fax: +91-11-573-1495) Nonstandard abbreviations: cpDNA, chloroplast DNA; RAPD, random amplified polymorphic DNA; UPGMA, unweighted pair-group method analysis Keywords: Musa cultivars zyxwvutsrqpo / Identification / Random amplified poly- morphic DNA / Restriction fragment length polymorphism for over a century, and are thus an important source of useful genes. However, the practice of conferring names in local dialects has resulted in numerous synonyms for the same cultivar [5]. This has created problems in germ- plasm conservation as elaborate field testing is required for germplasm characterization and classification using the morphological descriptors zyxw [4]. The problems are con- founded because the banana requires one to two years to flower and fruit. Various laboratory-based techniques have been tried. Diversity for anthocyanin profile [6], enzyme polymor- phisms [7-91, rRNA spacer-length heterogeneity [lo], chloroplast DNA (cpDNA) polymorphisms [ 111, restric- tion fragment length polymorphism (RFLP) [12, 131, vari- able number of tandem repeats (VNTRs) [14, 151 and analysis of specific highly repetitive DNA sequences [ 161 have been used to characterize diversity in Musa culti- vars. We had attempted to characterize and identify Indian Musa germplasm using isozyme polymorphism [17, 181 and VNTR loci [19]. The results of isozyme anal- ysis and DNA fingerprinting indicated the need for alter- nate techniques to distinguish some of the less diverse cultivars. In fact, very closely related cultivars, arising due to sports, is common in Musa [l, 201. This study was undertaken (i) to identify suitable primer sequences for random amplified polymorphic DNA (RAPD) analyses and probes for RFLP analyses and to develop genetic fin- gerprints of Musa cultivars for their characterization, identification and classification, (ii) to examine diversity prevalent among cultivars from different genomic groups, and (iii) to have a comparative evaluation of RAPD and RFLP techniques for cultivar identification and classification. zyxw 0 VCH Verlagsgesellschaft mbH, 69451 Weinheim, 1995 0173-0835/95/0909-1736 $5.00+.25/0