Genetic admixture and population structure analysis of Indian water buffaloes (Bubalus bubalis) using STR markers

We generated genetic diversity data for 10 different buffalo populations of India using 20 highly polymorphic microsatellite markers. The buffalo populations of Odisha were the primary focus, viz. Chilika, Paralakhemundi, Kalahandi, Sambhalpuri, and Manda. The total observed number of alleles ranged between 143 (Manda) and 301 (Paralakhemundi) with an average of 204 alleles per breed. The minimal spanning network based on Bruvo's distance, PCA based on the Fst values, and genetic admixture analysis using both the STRUCTURE and 'snapclust' could identify the Manda population distinct from other Odisha buffalo breeds as well as Chhattisgarhi buffalo breed. The Sambhalpuri buffalo population also clustered into two separate subpopulations, half of the unique sub-population located geographically south-wards displayed no admixture with any of the adjacent buffalo populations. The Sambhalpuri population requires elaborate analysis to confirm the existence of two distinct sub-populations and if they could be recognized as separate breeds. The limited number of sires in the Manda population has resulted in excess of heterozygosity. Furthermore, the Manda population is left with very little allelic richness and this poses a huge threat to the population's existence. In another way, the study has led to the identification of the Manda buffalo as a distinct population, and the germplasm has been registered based on the study.Funding provided by: Indian Council of Agricultural ResearchAward Number: 2.