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ThesisItem Open Access GENETIC DIVERSITY IN BANANA (Musa spp.) GERMPLASM OF ASSAM(AAU, Jorhat, 2018) Baruah, Sudeshna; Kotoky, U.An experiment was conducted at the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat to evaluate the huge diversity among the banana germplasm commonly available in the state of Assam. The experiment was laid out in Randomized Block Design with five replications the evaluation was done based on agro-biochemical parameters as well as the genetic diversity present within the genotypes using SSR markers. Based on growth, yield and fruit biochemical characters, the genotypes were clustered with respect to Euclidean distance and also by Trocher’s method. These clusters showed significant differences as compared to the genomic classification of banana. The genotypes were found to show significant diversity based on all the characters and considering all the variations, there were four major clusters found within the 24 genotypes under this investigation. The diploid balbisiana genotypes (Bhimkal and Athiakal) were found to occur in two different solitary clusters, whereas both the culinary genotypes (Kachkal green and white types) consisted a single cluster. The characters like pseudostem height, leaf area, planting to shooting interval, shooting to harvesting interval, crop duration, number of fingers per bunch, fruit weight, fruit volume, number of seeds, pulp: peel ratio, sugar content were found to show high GCV, PCV added with very high heritability and high genetic advance and therefore, these characters were identified to be subjected to improvement by direct selection. After the molecular study using 52 primers, a total of 32 primers were found to produce reproducible bands and 197 alleles were detected by them, of which 170 were polymorphic bands. Percent polymorphism thus obtained was 84.95%. The average polymorphism information content of the primers was 0.437, which was the highest for primer 41(0.913). In the study, a few molecular identities for different genotypes could be identified. A single band sized 400bp, specific to ‘Digjowa’ genotype was found with the SSR27. For both the red bananas considered in the study (Agnisagar and Gobin Tulsi), another specific band sized 250bp was identified with SSR22. The Jaccard’s similarity index was calculated using the molecular marker data and the average similarity index was found to be 0.552, which suggested sufficient diversity present within the genotypes. The maximum similarity based on this was found between ‘Manjahaji, and ‘Barjahaji’. Based on this similarity index, another clustering was done which found two major clusters within the 24 genotypes. In cluster 1, there were two subclusters and in cluster 2, there were three sub-clusters followed by a single genotype (‘Fesa Manohar’). This study had revealed that even among the genotypes belonging to same genomic group, there is sufficient differences based on agro-biochemical parameters and genetic information they carry. Moreover, from this study, the promising genotypes for different characters could be identified on the basis of growth, yield and fruit biochemical characters. Further, on the basis of the present study, efforts can be made for inclusion of more number of primers for even better characterization of the genotypic variability, detailed study for pest and disease resistance and more specifically by including gene specific primers.
