云南地方猪种随机群体与选育群的遗传差异(英文)
Genetic differentiations between randomly and selectively bred pig populations in Yunnan, China
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摘要: 为估计随机群体与选育群间的遗传差异, 测定了云南地方猪种102个个体438 bp的线粒体DNA D-loop片段, 涉及4个随机群体、1个保种群和1个核心群。检测的16个多态位点界定了20个单倍型, 撒坝猪核心群和版纳微型猪保种群的单倍型数量仅为3个和1个, 而4个随机群体的单倍型数量都在6个以上, 4个随机群体的单倍型多态度极显著高于这两个选育群(h=0.732对0.425和0.000, exact test, P≤0.0036)。结果发现, 选育会导致遗传多样性过低, 尽管在随机群体中有较高的遗传多样性, 基于此, 及早干预和合理的育种计划将会有效地阻止核心群和选育群的遗传多样性下降。否则, 选育甚至会在短短几年内使遗传多样性程度急剧下降, 表明育种、保种与遗传多样性保存之间存在着尖锐冲突。该文还讨论了几个群体的遗传关系。Abstract: To assess the genetic diversity between randomly and selectivelybred populations, we sequenced 438 bp of the mitochondrial DNA control region from 102 pigs. These samples represented four native pig breeds, one nucleus and one conservation herd from Yunnan, China. Twenty haplotypes with sixteen polymorphic sites were identified. The number of haplotypes in the nucleus herd of Saba pig and the conservation herd of Banna miniature pig were restricted to three and one, respectively, while the randomly bred pig populations exhibited over six haplotypes. Notably, haplotype diversity in randomly bred populations was significantly greater than the selectively bred populations (h=0.732 vs. 0.425 and 0, exact test, P≤0.0036). These findings demonstrate that selective breeding generated low genetic diversity compared to randomly bred pig breeds. A timely intervention and well programmed breeding approach would stop further genetic diversity reduction in the nucleus and conservation herds of native pig breeds. Otherwise, selective breeding would dramatically reduce genetic diversity in only several years, indicating that sharp contradictions exist between breeding, conservation and genetic diversity. Genetic relationships are discussed based on net genetic distances among pig populations.