摘要
采用线粒体控制区基因序列测定技术,分析了我国沿海重要经济鱼类鳓鱼4个地理群体的遗传结构及其变异。结果表明,我国的鳓鱼资源经过度捕捞后仍保持着丰富的遗传多样性,在检测的45个鳓鱼个体中共得到44个单倍型,单倍型多样性指数(H)高达0.964—1.000,平均核苷酸多样性指数(Pi)高达0.0100—0.0152,鳓鱼种群的多样性还表现在线粒体控制区的序列长短上,研究表明,鳓鱼线粒体控制区存在一个40bp长度的重复序列,依据重复次数的多寡而造成鳓鱼个体间的显著差异;对鳓鱼群体的遗传结构进行检测发现,我国鳓鱼群体内部存在明显的遗传分化,青岛群体与广州、厦门、舟山3个群体之间分化系数Fst达0.5284(P<0.01),群体间基因流则仅有0.4463,而3个群体内部则基因流明显;AMOVA检测和聚类分析也证实了上述观点,遗传距离分析表明青岛群体和其它3个群体净遗传距离达到0.034,仍属于种内群体之间的分化水平,依据分子钟理论推断两群体间的分化时间为更新世晚期,可能由更新世晚期海平面的反复升降导致了这两个类群的隔离与分化,并依靠鳓鱼本身的生物学特性维持至今。
Population genetics is important for successful and sustainable long-term fishery resources management. The genetic structure and genetic variation of four populations of Ilisha elongata in China coastal water are investigated by applying mitochondrial control region gene sequencing technology. Results show that despite long-time over-fishing, genetic variation of the fish yet remains plentiful in natural resources. 44 hapotypes were detected out of 45 individuals from the four populations. The hapotype diversity （H） and mean nucleotide diversity （Pi） are 0.964--1.000 and 0.0100--0.0152, respectively. The high genetic variation can be also reflected by the sequence length variation in mitochondrial control region. Results revealed a 40bp length repetitive sequence in the mitochondrial control region. Individuals differed from each other in frequency and length of the repetitive sequences, which contributed much to the genetic diversity. Molecular variance analysis reveals a strong genetic structure among populations. High Fst value （0.5284, P〈0.01） and Nm （0.4463） indicate high genetic differentiation between Qingdao population and populations of Guangzhou, Xiamen, and Zhoushan, while no genetic differentiation was detected among the latter three populations. AMOVA test and NJ tree construction have also proved the genetic structure between Qingdao and other 3 populations. The net genetic distance between the two lineage was 0.034, suggesting a moderate and none sub-species differentiation. The two lineages may diverge in late Pleistocene indicated by molecular clock analysis. The divergence might be resulted from sea level fluctuation in late Pleistocene, which was maintained and further reinforced by the biological nature of I. elongata itself.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2009年第3期330-337,共8页
Oceanologia Et Limnologia Sinica
基金
国家科技支撑计划项目
2007BAD43B00
浙江省重大科技计划国际合作项目
2006C14017
