摘要
哲罗鱼(Hucho taimen)是我国珍稀的土著冷水性鱼类,目前已处于濒危状态。为了解哲罗鱼的种群遗传多样性和遗传结构,该研究利用20对微卫星标记对9个野生哲罗鱼群体进行了分析。结果表明:9个哲罗鱼群体的观测杂合度在0.0994～0.8882,期望杂合度在0.2005～0.8759,PIC指数在0.3432～0.5261,其中呼玛河群体的遗传多样性较低。群体间的Fst在0.0246～0.2333(P<0.0001),Nm在0.8216～9.9292,群体间遗传分化较明显,基因交流少;群体的同胞系比例在27.78%～90.91%,说明近交压力较大,可能经历过遗传瓶颈或存在这样的风险。AMOVA分析表明,群体间各基因座遗传分化系数的均值为0.1081;聚类分析结果显示北极江段群体独立为一支,呼玛河群体与乌苏里江各群体聚为一支,黑龙江中上游各群体聚为一支。这些结果表明,哲罗鱼资源量的减少已经影响了群体间的基因交流。应杜绝对哲罗鱼资源破坏性捕捞,同时加强群体间基因交流,以期达到全面保护哲罗鱼种质资源的目的。
Taimen （Hucho taimen） is a native fish species in China and it is in the state of endangerment. To explain clearly the genetic diversity and genetic structure, 9 wild populations of taimen were investigated using 20 microsatellite markers. The results showed that their observed heterozygosity ranged from 0.0994 to 0.8882, the expected heterozygosity varied from 0.2005 to 0.8759, and the range of PIC index was from 0.3432 to 0.5261 while population from Huma River had low genetic diversity. Fst of matching group ranged from 0.0246 to 0.2333 （P〈0.0001）and Nm varied among 0.8216 to 9.9292, which indicated that the genetic differentiation was remarkable among populations.The half/full-sib family tests detected a proportion of half/full-sib family groups varying among 27.78% to 90.91%, showing a high inbred pressure and a risk of bottlenecks experienced by most groups. The AMOVA results showed that the global Fst was 0.1081; the clustering result showed that individuals from Beiji tributary of Heilongjiang River clustered as one clade, all individuals from Huma River and Wusuli River clustered as one clade and all individuals from the upper reaches of the Heilongjiang River clustered as another clade. All these results indicated that the decrease of taimen resource has affected the gene exchange among their populations. In order to achieve full protection of taimen germplasm resources, we should put an end to the destructive fishing for taimen and promotegene exchange among their populations.
基金
公益性行业科研专项(201003055)
中央级公益性科研院所基本科研业务费专项(2008HSYZX-SJ-08)
关键词
哲罗鱼
微卫星
遗传多样性
遗传结构
Hucho taimen
Microsatellite
Genetic diversity
Genetic structure
