Analysis of Genetic Diversity in 21 Genotypes of Indian Banana Using RAPDs and IRAPs Markers

Abstract

Table top banana (AAA) and cooking type plantines (BBB/ABB) are cultivated commercially for high yield and lucrative market value. Morphological similarities among the banana clones make identification difficult under field conditions. Random amplified polymorphic DNA (RAPD) and inter-retrotransposon amplified polymorphism (IRAP), were used to characterize genetic variations among 21 banana germplasm. IRAP primers were designed to determine ‘AA’ and ‘BB’ specific markers on the basis of repetitive and genome-wide dispersed long terminal repeat (LTR) retrotransposons. RAPD markers successfully detected genetic variation between genotypes. IRAP markers amplified either by a single primer or a combination of primers, based on LTR orientation, successfully amplified different retrotransposons dispersed in the Musa genome. The average level of polymorphism exhibited by RAPD and IRAP markers were 71.47 % and 81.3 % respectively that suggests substantial genetic variations among the tested varieties. All the 12 table-top varieties were clustered together while four cooking varieties i.e. Bantala-I, Bantala-II, Dakhkhnisagar and Athiakol with ‘BB’ formed a distinct group. These results suggested that IRAP markers were found more robust than RAPD markers to study the intra-group genetic diversity between table top and cooking banana.