GENETIC DIVERSITY AND PHYLOGENETIC RELATIONSHIPS BASED ON MILK PROTEIN GENETIC VARIANTS IN ROMANIAN SPOTTED, HOLSTEIN FRIESIAN AND MONTBÉLIARDE COWS
A.C. Grădinaru, Daniela Elena Ilie, Şt. Creangă
The present study aimed to analyze the milk protein genetic diversity in three of the most common breeds in Romanian farms (Romanian Spotted, Holstein Friesian and Montbéliarde). It was also tried to find possible relationships among the studied breeds solely using the milk protein polymorphism information. Therefore, the genetic similarity index using the Mayala-Lingsterm test and the magnitude of genetic divergence between two populations as Nei's genetic distance were calculated. In order to establish the genetic diversity, the homozygotic coefficient based on the homozygotic genotypes frequencies was statistically interpreted.
The results showed that the genetic distance between the Romanian Spotted and Holstein Friesian breeds was lower than the genetic distance between the Romanian Spotted and Montbéliarde ones. The genetic distance between the Holstein Friesian and Montbéliarde breeds showed a slightly higher value than that between the Romanian Spotted and Montbéliarde ones. The homozygotic coefficient ranged from 22.50 to 28.47%. These results are normally considered for every panmictic population which is in Hardy-Weinberg equilibrium.
Key words: cattle breeds, genetic diversity, phylogenetic relationships