| 摘要: |
| 2019~2020年在三峡库区巫山(WS)、万州(WZ)、丰都(FD)、涪陵(FL)4个采样点采集到新建短颌鲚(Coilia brachygnathus)种群153尾个体,基于鳞片和10个微卫星DNA标记进行年龄结构、生长特征与遗传多样性分析。结果显示,短颌鲚种群体长分布范围为102.1~301.6mm,平均体长(196.6±40.0)mm;体重分布范围为1.90~79.70g,平均体重(17.70±13.06)g。短颌鲚种群年龄组为1~5龄,其中2龄和3龄为优势年龄组,占总个体数的82.35%。体长-体重呈幂函数指数关系,属于正异速生长类型。微卫星DNA标记分析结果显示,10个微卫星位点共检测到82个等位基因,各群体平均等位基因数(Na)为5.600 0~7.300 0,平均有效等位基因数(Ne)为3.541 4~3.831 5,平均观测杂合度(Ho)为0.617 7~0.700 0,平均期望杂合度(He)为0.682 3~0.702 9之间,平均多态信息含量(PIC)为0.628 5~0.648 4。4个群体的遗传多样性水平均较高,呈现出由三峡库区下游至上游逐渐减小的特点。遗传结构分析结果显示,群体间遗传分化水平很低,遗传变异主要来源于个体内部。结果表明,三峡库区短颌鲚种群处于快速扩张阶段,4个群体均具有较丰富的遗传多样性,遗传结构未发生显著群体分化,群体间基因交流频繁。由此提示,三峡库区短颌鲚很可能来源于三峡大坝下种群扩张迁入三峡库区水域而繁殖建群。 |
| 关键词: 短颌鲚 三峡水库 年龄 生长 微卫星DNA 遗传多样性 新建种群 |
| DOI：10.11693/hyhz20210900217 |
| 分类号:Q953; Q958; S965 |
| 基金项目:重庆市农业农村委员会增殖放流效果评价项目,JQCG2020-20号;重庆市农业农村委员会生态渔产业技术体系岗位专家项目,4322000101号。 |
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| AGE STRUCTURE, GROWTH CHARACTERISTICS AND GENETIC DIVERSITY OF NEWLY-ESTABLISHED POPULATION OF SHORTJAW ANCHOVY (COILIA BRACHYGNATHUS) IN THE THREE GORGES RESERVOIR AREA |
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CHEN Zhe-Yu1, TAO Yi-Xi1, YE Qin2, WANG Guo1, WANG Wen-Bo1, FAN Shi-Qi1, HE Chun1, LI Yun1,3
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1.College of Fisheries, Institute of Three Gorges Ecological Fisheries of Chongqing, Southwest University, Chongqing 400715, China;2.School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China;3.Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, Southwest University, Chongqing 400715, China
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| Abstract: |
| From 2019 to 2020, 153 individuals of newly-established shortjaw anchovy (Coilia brachygnathus) population were collected from four sampling sites in Wushan (WS), Wanzhou (WZ), Fengdu (FD), and Fuling (FL) in the Three Gorges Reservoir. The age structure, growth characteristics, and genetic diversity were analyzed based on the scales and 10 microsatellite DNA markers. Results show that the body length of the C. brachygnathus populations ranged 102.1~301.6 mm on average of (196.6±40.0) mm; the body weight 1.90~79.70 g on average of (17.70±13.06) g; and the age group was 1~5-year-old, mostly (82.35%) 2~3-year-old. The relationship between body length and body weight can be described by a power function exponential relation showing positive allometric growth of the fish. The microsatellite DNA marker analysis revealed 82 alleles at 10 microsatellite loci. In each group, the average number of alleles (Na) ranged from 5.600 0 to 7.300 0, the average effective number of alleles (Ne) ranged from 3.541 4 to 3.831 5, the average observed heterozygosity (Ho) ranged from 0.617 7 to 0.700 0, the average expected heterozygosity (He) ranged from 0.682 3 to 0.702 9, and the average polymorphic information content (PIC) ranged from 0.628 5 to 0.648 4. The four groups showed a high level of genetic diversity, and the diversity gradually decreased from downstream to upstream. Genetic structure analysis showed that the level of genetic differentiation among groups was very low, and the genetic variation was mainly from within-individuals. The C. brachygnathus population in the Three Gorges reservoir was in the stage of rapid expansion and genetically diversified in the four groups with no significant population differentiation in genetic structure, and gene exchange was frequent among populations. It is suggested that C. brachygnathus in the Three Gorges reservoir may originate from the population expansion downstream of the Three Gorges Dam and migrate into the Three Gorges reservoir for breeding and developing. |
| Key words: shortjaw anchovy(Coilia brachygnathus) Three Gorges Reservoir age growth microsatellite DNA genetic diversity newly-established population |
