Studies On Relationship Of Genetic Marker And Heterosis

This paper deals with analysis of population genetics and the relationship of genetic markers to performance and heterosis of seven breed combinations in 136 pigs.1.Eight plasma protein (enzyme) polymorphisms were examined by using the method of polyacymide gel electrophoresis, 25 genotypes and 19 alleles were detected. Based on allelic frequency of various locus the average heterozygosities were caculated: Daroc(d)0.4017, Landrace(L)0.3926, Large white(W)0.3615, LXW 0.4508,WXL 0.4497.DXLW 0.4896, W XLW 0.4611. The results show purebred with the lowest average heterozygosity and other crossbreds with the higher.2.Genetic distances measured by both biochemical and molecular marker show that parental genetic distance of D -LW combination is the largest, that of L and W -L is the next and W LW is the smallest, and the genetics distances based on the two markers show extremely significant positive correlation (r=0.9673,p<0.01)3.The values of average band sharing of offsprings in breed combination are W ?LW> D ?LW, W ?L, L ?W in orders, they show no relationship with parental genetic distances and gene heterozygosities.4.Parental genetic distance shows positive correlation with heterozygosities. Heterozygosities show positive correlation with daily gain and ham percentage, negative correlation with loin eye area and lean percentage. Parental genetic distances show positive correlation with dressing percentage, backfat thickness but negative correlation with loin eye area, lean percentage, cooked meat percentage.Wang Zhonghua(Animal Genetic Breeding & Reproduction) Directed by Prof. Shi Qishun...