Estimation of genetic diversity in Siri cattle from India.

Siri cattle, a dual purpose breed of India is currently showing declining population trend. Siri animals have been developing through natural selection and show high adaptation to wide range of hilly terrain (altitudes 150-2500 m). The present work evaluated the genetic diversity of 23 FAO recommended microsatellite loci in a sample of 50 animals. The allele and genotype frequencies, heterozygosities and gene diversity were estimated. A total of 141 alleles were detected by the 23 microsatellite markers investigated. Microsatellites were highly polymorphic with mean allelic number 6.13 +/- 1.63 (ranging from 3-10 per locus). The observed heterozygosity in the population varied from 0.26-0.80 with the mean of 0.53 +/- 0.16, indicating substantial genetic variation in this population. Heterozygote deficiency and mutation-drift equilibrium hypothesis were also examined. Population exhibited heterozygote deficit to the tune of 22.1%. Population was found to be in mutation-drift equilibrium. Substantial genetic variability verified in Siri cattle despite its reducing population size suggests that this breed has a rich reservoir of genetic diversity. This fact and its marked environmental adaptation reinforce the importance of its preservation as a pure breed, and/or its use in agricultural exploitation.