陇东黄土高原石鸡的遗传多样性与保护

Genetic diversity and protection of chukar partridge (Alectoris chukar) on the Loess Plateau of eastern Gansu

石鸡 (Alectorischukar)是我国北方重要的猎鸟 ,由于栖息地片断化和人类狩猎 ,陇东黄土高原上的石鸡数量正日益减少。本文用PCR直接测序的方法 ,测定了陇东黄土高原 8个石鸡种群mtDNA控制区I区和部分II区的4 91个碱基 ,探讨其遗传多样性。 78个样本共发现 2 4个变异位点 (占所测序列的 4 .89% )和 2 5种单倍型 (占所测样本的 32 .0 5 % )。 8个种群中 ,铜川种群的序列变异率、单倍型多样性和核苷酸多样性都最高 ,分别是 0 .4 7、0 .82和 0 .0 0 2 9;而红回种群的最低 ,仅分别为 0 .10、0 .2 8和 0 .0 0 0 8,这与红回种群受奠基者效应、遗传隔离和自然选择的作用有关。 8个种群共享 1种单倍型C1,说明它们来自共同祖先 ,是 1个单系群 ,属于 1个进化显著单元 ,但它们聚成两个集群。两集群间单倍型相似性指数仅 0 .15 ,遗传距离达 0 .4 3% ,单因素方差分析显示遗传变异差异显著 (F =5 .0 2 >F0 .0 5(14 ,1) =4 .0 6 ) ,分别有 13种和 10种单倍型为两个集群所特有。基于遗传差异性 ,陇东黄土高原的石鸡应分为两个管理单元进行保护 ,尤其对遗传变异和遗传多样性最高的铜川种群应进行重点保护。

Chukar partridge ( Alectoris chukar ) is a very important bird for hunting in northern China. Currently chukar partridges are threatened by habitat loss and fragmentation, hunting, and human persecution on the Loess Plateau of eastern Gansu. We used polymerase chain reaction and dideoxy direct sequencing methods to analyze the genetic diversity of chukar partridge. A total of 491 nucleotides of the mitochondrial DNA control region gene were sequenced in 78 chukar partridges of eight populations collected from the Loess Plateau. The 24 variable sites (4.89% of the entire sequences) defined 25 haplotypes (32.05% of all the samples). The sequence variation, haplotype diversity and nucleotide diversity of the Tongchuan population were the largest among the eight populations, up to 0.47, 0.82 and 0.0029 , respectively, while those of Honghui population were the lowest, 0.10, 0.28 and 0.0008, respectively. This might result from founder effect, genetic isolation or natural selection. The eight populations shared one haplotype C1, which indicated that they came from a common ancestor and belonged to one monophyletic group and one evolutionarily significant unit. However, they clustered into two groups. The haplotype similarity index between the two groups was only 0.15, and genetic distance was 0.43%. The genetic variability was significantly different between the two groups according to one way analysis of variance ( F =5.02>F 0.05 (14,1)=4.06). It is suggested that the chukar partridge throughout the Loess Plateau of eastern Gansu should be protected as two management units since the demographic connection between them is low. The Tongchuan population, with the highest genetic variation and genetic diversity, should be well protected.