Abstract: The correlation of the Gansu Alpine Merino DRB1 gene intron 2 microsatellite polymorphism and growth performance were analyzed by growth performance measurement, DNA sequencing and microsatellite DNA polymorphism detection. The results showed that the Gansu Alpine Merino DRB1 gene intron 2 microsatellite repeat unit was composed of GT and GA, which belonged to compound microsatellite type. Thirteen alleles and forty genotypes were detected on 220 Gansu Alpine Merino, allele 201, 195 and 193 bp were advantagous, genotype 201/201 bp was advantagous. The microsatellite locus PIC was 0.830, the heterozygosity was 0.847, which was a highly polymorphic locus. Analysis of correlation indicated that the birth weights of 183, 191, 207 and 197 bp alleles on Gansu Alpine Merino groups were significantly higher than those of the 165, 219, 195, 213 and 203 bp allele populations (P<0.01), at the same time significantly higher than that of the 179, 189, 193 and 201 bp allele populations (P<0.05), birth weights of the group containing 179, 189, 193 and 201 bp allele were significantly higher those that of the 165, 219,165, 213 and 203 bp alleles population (P<0.05). For Gansu Alpine Merino, based on the comprehensive consideration of live weight of 1 month, 2 months, 3 months and 6 months of age, it was believed that the groups containing 197 and 207 bp allele had higher weights, from the perspective of Gansu Alpine Merino DRB1 gene intron 2 microsatellite locus selection, the individuals containing 197 and 207 bp allele should be reserved when selected as breeder, and it would be likely to improve the birth weight and slaughter weight (6 months) of Gansu Alpine Merino.

Key words: Gansu Alpine Merino, microsatellite DNA, DRB1 gene, growth rate