Genetic Diversity of Philippine Native Pigs (Sus scrofa L.) from Quezon and Marinduque Based on Morphological and Microsatellite Markers

Abstract

Nine microsatellite markers recommended by the Food and Agriculture Organization were used to measure the genetic diversity of Quezon and Marinduque native pig populations – with a total of 37 and 40 individuals, respectively. All markers were discovered to be polymorphic, with a mean number of alleles per locus of 10. Marinduque native pigs were found to have a mean effective number of alleles (EA), mean observed heterozygosity (HO), mean expected heterozygosity (HE), and mean polymorphic information content (PIC) of 5.005 ± 0.547, 0.673 ± 0.040, 0.780 ± 0.024, and 0.76 ± 0.03, respectively. By contrast, Quezon native pigs had mean EA, mean HO, mean HE, and mean PIC values of 5.280 ± 0.787, 0.634 ± 0.044, 0.773 ± 0.035, and 0.75 ± 0.04, respectively. Between the two populations, the heterozygosity (HE > HO) and positive values of FIS (0.1714) and FIT (0.1868) indicated a low number of heterozygotes, suggesting the possibility of inbreeding. The test of Hardy-Weinberg equilibrium (HWE) showed that three loci each in the Quezon and Marinduque native pig populations deviated from HWE. Although morphological analysis revealed significant differences in snout shape, head profile, ear type, and all morphometric traits, a low level of genetic differentiation between the two populations was observed (FST = 0.0186; Nei genetic distance = 0.130; Nei unbiased genetic distance = 0.082). Overall, these findings imply that further studies on the genetic improvement and conservation of Philippine native pigs are required for the development of signature pig breeds across the country.