Abstract: As an endangered species listed in the Class Ⅱ protected species of the national government of China, wapiti (Cervus canadensis xanthopygus) in northeast China has been experiencing population contraction and gene flow block between populations in recent years, and it is hard to find its traces in many areas. It is an urgent need to further evaluate the genetic changes of the population, especially the genetic diversity and inbreeding decline, so as to enhance the pertinence of conservation and management. In this study, 409 suspected fecal samples of wapiti were collected from six key research areas in Daxing'an, Xiaoxing'an, and Changbai Mountains. Firstly, species identification was carried out based on mtDNA Cyt b gene sequencing technology, and the positive samples were supplied for further individual identification by microsatellite technology. Finally, 172 wapiti individuals were identified from the 409 fecal samples. The results showed that there were 14 variation sites and 11 haplotypes in the Cyt b sequence of wapiti. In the populations, the haplotype diversity and nucleotide diversity of Cyt b gene were 0.849 (0.105-0.732) and 0.678% (0.099%-0.775%), respectively. Based on 10 microsatellite loci, we found that the mean number of alleles was 5.7 (5.2-7.2), the effective number of alleles was 3.3 (2.5-4.1), the average observed heterozygosity was 0.687 (0.644-0.725), the average expected heterozygosity was 0.619 (0.564-0.689), and the inbreeding coefficient was -0.113 (-0.160 to-0.037) in the populations. The results showed that the genetic diversity was at a medium level for populations, among which the Shuanghe and Tieli populations were the highest, followed by the Gaogestai and Huangnihe populations, and the Fangzheng and Muling populations were the lowest. The population decline and isolation of the distribution area affected the genetic diversity pattern of the six local populations. The high proportion of rare haplotypes and alleles suggested a risk of decreasing genetic diversity in the future. The Gaogestai and Huangnihe populations displayed significant differences in haplotype diversity and nucleotide diversity, which may be the result of rapid growth after the population decline. The negative inbreeding coefficients of populations showed no risk of inbreeding. It is suggested that individuals with rare haplotypes and alleles should be key targets in monitoring and protection. Additionally, promoting exchanges of individuals with nearby populations and releasing artificially bred populations in the field at the appropriate time may improve the gene exchange between individuals and accelerate population restoration.

Key words: Cervus canadensis xanthopygus, mtDNA, Microsatellite, Genetic diversity, Fecal DNA

摘要： 东北马鹿(Cervus canadensis xanthopygus)为国家二级重点保护野生动物，近些年其种群数量急剧下降、分布区不断退缩、种群基因交流受阻，很多地区更是难觅其踪迹。亟需对其种群的遗传变化，特别是遗传多样性和近交衰退等种群遗传信息开展进一步评价，增强保护与管理的针对性。本研究在大、小兴安岭和长白山脉的6个重点研究区域，共收集409份疑似马鹿粪便样本。首先基于mtDNA Cyt b 基因测序技术进行物种鉴定，并对鉴定为马鹿的阳性样本利用微卫星技术进行个体识别。结果共识别出172只东北马鹿个体；Cyt b 基因序列共检测出 14个变异位点和 11个单倍型，单倍型多样性为0.849(0.105~0.732)，核苷酸多样性为0.678%(0.099%~0.775%)。10个微卫星位点检测出种群平均等位基因数为5.7(5.2~7.2)，有效等位基因数为3.3(2.5~4.1)，观测杂合度为0.687(0.644~0.725)，期望杂合度为0.619(0.564~0.689)，近交系数为-0.113(-0.160~-0.037)。结果表明，东北马鹿种群遗传多样性处于中等水平，其中双河和铁力种群最高，高格斯台和黄泥河种群次之，方正和穆棱种群最低。种群历史数量的下降与分布区的隔离影响着各局域种群的遗传多样性格局。种群内高比例的稀有单倍型和等位基因显示，东北马鹿种群未来存在遗传多样性下降的风险。高格斯台和黄泥河种群单倍型与核苷酸多样性水平的差异，为种群历史数量下降后快速增长的结果。东北马鹿各局域种群的近交系数均为负值，非杂合度不足，提示种群尚无近交风险。建议对东北马鹿稀有单倍型和等位基因个体重点监测和保护，并促进与附近区域个体的交流，恰当时期考虑圈养种群野外放归，以提高野外个体间基因交流和快速种群恢复。

关键词: 东北马鹿, mtDNA, 微卫星, 遗传多样性, 粪便DNA