| [Objective] To reveal the maternal genetic diversity, population genetic structure and genetic background of Tongde yak population in Qinghai Province at molecular level, the mtDNA D-loop regions of 60 (32♂, 28 ♀）Tongde yaks were sequenced and checked manually. [Method] The genetic diversity, population genetic structure and phylogenetic relationship of Tongde yaks were analyzed by BioEdit, DnaSP, Arlequin and Network software. [Results] The length of mtDNA D-loop region of Tongde yaks was 890-894 bp. After excluding 12 InDel sites, 59 polymorphic sites were detected, including 17 single polymorphic sites and 42 parsimony information sites. 31 haplotypes were identified according to the nucleotide variations among sequences, in which H8 was the dominant haplotype. The haplotype diversity was 0.935±0.023 and the nucleotide diversity was 0.012±0.006. Compared with other yak breeds (populations) (e.g. Plateau, Huanhu and Datong yak breeds etc.) in Qinghai Province, the haplotype diversity of Tongde yak population was relatively higher, indicating that it had rich maternal genetic diversity. The network diagram constructed by MJ method showed that 31 haplotypes of Tongde yaks were distributed in A, B, C, D and E haplogroups. These haplotypes/haplogroups could be divided into two lineages, which indicated that Tongde yaks had two maternal origins. [Conclusion] Tongde yak population owned rich maternal genetic diversity, which is composed of five haplogroups (A, B, C, D and E) individuals distributed in two genetic lineages with two maternal origins. |