关键词: 多浪羊, mtDNA D-loop区, 遗传多样性

Abstract: We used the Duolang sheep as object in this study，researched the genetic diversity of mitochondrial D-loop region of sheep，layed the foundation for the study of the origin and evolution of Duolang sheep. The results showed that the length of mtDNA D-loop is 945~1 039 bp.　The percentage of A, T, G, C was 29.4%, 27.7%, 17.7% and 25.1%, respectively. A+T was 571%, 　G+C was 42.8%. The study acquired 26 haplotypes, 56 polymorphic sites. Single polymorphism sites and concision information sites were 42 and 14 respectively. The average number of nucleotide differences k is 5.289, nucleotide diversity P is 0.024 15, which indicated that genetic diversity of Duolang sheep was low and key protection measures should be taken. Furthermore, it was also found that Duolang sheep experienced population expansion, there might be D or E lineage of the matrilineal origin besides A, B and C lineage.

Key words: Duolang sheep, mtDNA D-loop region, genetic diversity