Association Analysis Of Microsatellite Diversity With Production Traits In Minxian Black Fur Sheep

Minxian black fur sheep is a local fur sheep breed in Gansu Province.The study of genetic diversity and correlation of production traits can provide theoretical basis for the protection and utilization of germplasm resources.Based on the analysis of the path relationship between body weight and body size traits,this paper chosed 24 pairs of microsatellite primers commended by FAO to analyze the genetic diversity of 144 Minxian black fur sheep.Meanwhile,It also used the general linear model of SPSS 21.0 software to analyze relevance between microsatellite markers and phenotypic data of traits.The results showed that:1.Variation coefficients of production traits of Minxian black fur sheep aged 12,24 and36 months were 8.44%¹9.89%,4.24%⁸.52%and 4.31%¹0.62%,respectively.2.The results of correlation analysis between body weight and body size traits showed:except there was no significant correlation between chest width and body weight at 12months old?P>0.05?,the other body size indicators were positively correlated with body weight?P<0.05?.3.Stepwise multiple regression analysis showed that the optimal regression equation at 12months old:Y=0.409 X₅+0.246 X₁-19.850,R²=0.546;at 24 months oid:Y=0.485 X₅+0.929X₃-19.569,R²=0.719;at 36 months old:Y=1.086 X₃+0.327 X₂+0.251 X₁-10.207,R²=0.930.4.Path analysis of body weight and body size traits showed:at 12 and 24 months age,the direct effect of chest circumference on body weight was the greatest,and the indirect effect of body height and chest width on body weight through chest circumference was greater than that of itself;at 36 months age,the direct effect of chest width on body weight was the greatest,and the indirect effect of body height on body weight through chest width was the greatest.5.Analysis of microsatellite genetic diversity showed:a total of 231 alleles were found in24 microsatellite locus,the average number of alleles was 9.63;the alleles frequency of population were 0.0104⁰.7396,alleles size were 97²85 bp;the average number of effective alleles was 3.6540;the average observed heterozygosity was 0.4839;the average expected heterozygosity was 0.6956;the average genetic heterozygosity was 0.6883;and the average polymorphic information content was 0.6527.MAF70 locus had the hightiest numbers of alleles?Na=15?,numbers of effective alleles?Ne=8.2433?,expected heterozygosity?He=0.8879?and polymorphism information content?PIC=0.8673?,OarFCB128 had the hightiest observe heterozygosity?Ho=0.8125?;the numbers of alleles at OarAE129?Na=4?and the observed heterozygosity at OarFCB304?Ho=0.2500?was the least,SRCRSP9 had the lowest expected heterozygosity?He=0.4357?and polymorphism information content?PIC=0.4070?.19 of locus were in Hardy-Weinberg imbalance.The results showed that Minxian black fur sheep had abundant genetic diversity and strong environmental adaptability.24 microsatellite locus could be used for correlation analysis of production traits of Minxian black fur sheep.6.The association analysis of 24 microsatellite markers with production traits showed that21 locus were correlated with body weight,body height,body length,chest width,chest depth and chest circumference of Minxian black fur sheep aged 12,24 and 36 months,respectively?P<0.5?.At 12 months old,there were 7 locus related with body weight:DYMS1,SRCRSP9,ILSTS11,OarFCB304,OarJMP58,MAF65,MAF70;there were 7 locus related with body height:OarFCB128,OarVH72,ILSTS28,MAF214,MAF33,OarJMP29,MAF70;there were 3locus related with body lenght:OarFCB193,MAF65,MAF70;there was 1 locus related with chest width:ILSTS28;there were 4 locus related with chest depth:MAF214,OarFCB304,OarJMP29,MAF209;there were 5 locus related with chest circumference:ILSTS11,OarFCB193,OarJMP58,MAF65,MAF70.At 24 months old,there were 7 locus related with body weight:SRCRSP9,ILSTS11,MAF33,OarFCB193,OarJMP29,OarJMP58,MAF209;there were 4 locus related with body height:MCM140,OarFCB193,OarJMP58,MAF70;there were4 locus related with body lenght:DYMS1,MAF214,MAF65,MAF209;there was 1 locus related with chest width:ILSTS5;there were 4 locus related with chest depth:BM8125,ILSTS5,ILSTS11,OarFCB304;there were 7 locus related with chest circumference:BM8125,SRCRSP9,MCM140,OarFCB193,OarJMP29,OarJMP58,MAF209.At 36 months old,there were 5 locus related with body weight:OarHH47,OarVH72,OarCB226,OarFCB193,OarJMP29;there were 5 locus related with body height:OarHH47,DYMS1,SRCRSP9,MCM140,OarFCB193;there were 4 locus related with body lenght:OarAE129,ILSTS5,OarFCB304,MAF65;there was 6 locus related with chest width:OarFCB128,OarVH72,BM8125,OarCB226,OarFCB193,OarFCB304;there were 4 locus related with chest depth:OarAE129,OarCB226,MAF33,MAF65;there were 5 locus related with chest circumference:ILSTS5,MCM140,OarFCB193,OarJMP29,MAF65.In summary,the effects of body size traits on body weight in Minxin black fur sheep varied with age;at the same time,this population was rich in genetic diversity,and the degree of association between the selected loci and production traits is higher.Minxin black fur sheep as a national animal genetic resources,the protection of the variety was urgent.