Liu Gang, Zhao Qianjun, Lu Jian, Sun Feizhou, Han Xu, Zhao Junjin, Feng Haiyong, Wang Kejun, Liu Chousheng
National Center for Preservation and Utilization of Animal Genetic Resources, National Animal Husbandry Service, Beijing 100193, China.
Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Asian-Australas J Anim Sci. 2019 Feb 9;32(10):1501-1510. doi: 10.5713/ajas.18.0737. Print 2019 Oct.
An experiment was conducted to evaluate genetic diversity of 26 Chinese indigenous goats by 30 microsatellite markers, and then to define conservation priorities to set up the protection programs according to the weight given to within- and between-breed genetic diversity.
Twenty-six representative populations of Chinese indigenous goats, 1351 total, were sampled from different geographic regions of China. Within-breed genetic diversity and marker polymorphism were estimated calculating the mean number of alleles (MNA), observed heterozygosities (HO), expected heterozygosities (He), fixation index (FIS), effective number of alleles (NE) and allelic richness (Rt). Conservation priorities were analyzed by statistical methods.
A relatively high level of genetic diversity was found in twenty-four populations, the exceptions were in the Daiyun and Fuqing goat populations. Within-breed kinship coefficients matrix identified seven highly inbred breeds which should be concerned. Of these, six breeds will get a negative contribution to heterozygosity when the method was based on proportional contribution to heterozygosity. Based on Weitzman or Piyasatian and Kinghorn methods, the breeds distant from others i.e. Inner Mongolia Cashmere goat, Chengdu Brown goat and Leizhou goat will obtain a high ranking. Evidence from Caballero and Toro and Fabuel et al. method prioritized Jining Gray goat, Liaoning Cashmere goat and Inner Mongolia Cashmere goat, that in agreement with results from Kinship-based methods.
Conservation priorities had planned according to multiple methods. Our results suggest Inner Mongolia Cashmere goat (most methods), Jining Gray goat and Liaoning Cashmere goat (high contribution to heterozygosity and total diversity) should be prioritized based on most methods. Furthermore, Daiyun goat and Shannan White goat also should be prioritized based on consideration of effective population size. However, if one breed could survive in changing conditions all the time, the straightforward approach is to increase its utilization and attraction for production via mining breed germplasm characteristic.
通过30个微卫星标记评估26个中国本土山羊品种的遗传多样性,然后根据品种内和品种间遗传多样性的权重确定保护优先级,以制定保护计划。
从中国不同地理区域采集了26个具有代表性的中国本土山羊群体,共1351只。通过计算等位基因平均数(MNA)、观察杂合度(HO)、期望杂合度(He)、固定指数(FIS)、有效等位基因数(NE)和等位基因丰富度(Rt)来估计品种内遗传多样性和标记多态性。采用统计方法分析保护优先级。
在24个群体中发现了相对较高水平的遗传多样性,例外的是戴云山羊和福清山羊群体。品种内亲缘系数矩阵确定了7个高度近交的品种,应予以关注。其中,当基于对杂合度的比例贡献方法时,6个品种对杂合度将产生负贡献。基于韦茨曼方法或皮亚萨蒂安和金霍恩方法,与其他品种距离较远的品种,即内蒙古绒山羊、成都麻羊和雷州山羊将获得较高排名。卡瓦列罗和托罗方法以及法布尔等人的方法的证据表明,济宁青山羊、辽宁绒山羊和内蒙古绒山羊具有优先地位,这与基于亲缘关系的方法的结果一致。
已根据多种方法规划了保护优先级。我们的结果表明,基于大多数方法,内蒙古绒山羊(大多数方法)、济宁青山羊和辽宁绒山羊(对杂合度和总多样性贡献高)应被列为优先保护对象。此外,基于有效种群规模的考虑,戴云山羊和陕南白山羊也应被列为优先保护对象。然而,如果一个品种能够在不断变化的条件下一直生存下去,直接的方法是通过挖掘品种种质特性来提高其在生产中的利用率和吸引力。