Microsatellite-based genetic diversity and relationship analyses of three genetic groups of domesticated mallard ducks (Anas platyrhynchos domesticus L.)

This study was undertaken to provide molecular and morphological characterizations and to determine genetic diversity and relationships among the Philippine Mallard, Khaki Campbell, and Pekin ducks. A total of 90 unrelated ducks representing the three genetic groups were used. Twenty-one of the 28 microsatellite primers employed are polymorphic. Among the three genetic groups, the average observed and effective number of alleles ranges from 2.238 to 2.714 and 1.565 to 1.934, respectively. Likewise, the average observed and expected heterozygosity ranges from 0.297 to 0.432 and 0.308 to 0.422, respectively. The average polymorphism information content extends from 0.303 to 0.414. The average within population inbreeding estimate among the three genetic groups of mallard ducks is -0.0020 while total inbreeding estimate is 0.1292. On the other hand, the measurement of population differentiation has a value of 0.1309. Relationship analyses also show that the Philippine Mallard is genetically closer to the Khaki Campbell (DS=0.0944) than with the Pekin (DS=0.1523). The genetic distance between the Khaki Campbell and the Pekin is 0.1386. While the Philippine Mallard is less genetically diversified, it is more phenotypically variable compared with the Khaki Campbell and Pekin in terms of plumage, bill and shank colors. The Pekin was found out to be significantly bigger compared with the Philippine Mallard and Khaki Campbell in terms of bodyweight, breast width, breast depth, Keel length, and shank length. The Philippine Mallard and the Khaki Campbell are more or less similar in terms of these morphometric traits.Private alleles that can be used as breed indicators were observed in the Pekin and Khaki Campbell ducks although these unique allelic patterns have low rates of incidence. No private allele for this purpose was discovered in the Philippine Mallard. It was also found out that microsatellite-based individual multi-loci heterozygosity had significant correlation with fitness traits such as bodyweight, breast width, breast depth, and keel length at sexual maturity in the three genetic groups of mallard ducks.