Analysis of intraspecific genetic variation in Musa balbisiana Colla from Meghalaya as revealed by Single Primer Amplification Reaction approach

Abstract

The Indian subcontinent is considered to be the major centre of hybridization of the wild Musa progenies, as it forms the centre of secondary origin of the taxa and therefore expected to exhibit a high degree of diversity. Musa balbisiana Colla is known to be one of the wild progenitors of cultivated bananas and plantains. Knowledge of genetic variability is very important for contemplating any conservation and management programmes. Single Primer Amplification Reaction (SPAR) approach i.e., a combination of random amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR) and directed amplification of minisatellites DNA (DAMD) markers function as important tools for analyzing genetic variation in plants. They collectively provide a comprehensive description of the nature and the extent of existing natural genetic diversity, as the primers target different regions of the genome. A total of 47 SPAR primers (RAPD-25, ISSR-12 and DAMD-10) with high reproducibility were used for analysis of intraspecific genetic variation of the 12 genotypes of M. balbisiana, which yielded 331 polymorphic bands. The RAPD, ISSR and DAMD markers revealed 82.63 %, 90.36 % and 84.72 % of polymorphic bands respectively. The polymorphic information content (PIC) values were almost identical for each marker system while the resolving power (Rp) was found to be highest in DAMD (4.10). The dendrogram obtained showed the presence of two main clusters in all the analyses, with some genotypes (MB10-MB11 and MB5-MB7) always maintaining and manifesting their strong genetic relationship by clustering together in almost all the analyses. Combinations of such markers can be considered as more effective and promising tool for assessing genetic variation in other Musa species as well.