Karyotype Variation in Eight Cultivars of Indian Dessert Banana (Musa acuminata L.) of Section Eumusa From Odisha, India

Abstract

Banana (Musa spp.) cultivars especially dessert banana are important cash crop with high market demand all over the world as an integral part of the diet. The need for assessment of cytogenetic characters in Musa cultivars is inevitable as out of thousands of cultivars, cytogenetic characterization of most of them remains unresolved due to difficulties like small chromosome size, diversity in ploidy levels and high cultivar diversity which behave differently to standardized cytogenetic protocols. In this report, somatic chromosome number, detailed karyotype analysis including total chromosome length, volume, form percentage, Interphase Nuclear Volume (INV) were accessed on eight dessert type of Musa accessions from different places of Odisha. All the cultivars studied were found triploid (2n = 33) with a basic chromosome number of x=11. The karyotype formulae were assigned to each cultivar by grouping the chromosome according to their shared characteristics. The total chromosome length ranged from 54.95 µm in cv. Robusta to 81.5 µm in cv. Kathia with symmetric karyotype in all the studied cultivar. Karyotype formula revealed structural alteration of chromosome with Total Form percentage (TF%) variation from 35.65% in cv. Amritapani to 41.68% in cv. Patakpura that confirms more number of nearly median constricted chromosome as compared to sub-median chromosome. The total chromosome volume recorded from 10.78 µm³ in cv. Robusta to 15.99 µm³ in cv. Khatia and the INV varied from 1336.44 µm³ in cv. Dwarf Cavendish to 2048.37 µm³ in cv. Patakpura. The recorded structural variation might be due to differential genome specific condensation of chromosome. Chromosome length and volume found statistically significant among the cultivars.