【作者】 孔杰；

【导师】 刘瑞玉； 相建海；

【作者基本信息】 中国科学院研究生院（海洋研究所） ， 海洋遗传学， 2002， 博士

【摘要】 中国对虾主要分布于我国的黄渤海海域，是我国重要海洋渔业资源及增养殖对象。捕捞年产量超过4万吨。80年代因捕捞过量，使资源遭受严重破坏。进入90年代，中国对虾的自然资源量持续下降，秋捕产量从千吨水平下降至百吨水平。每年大规模的人工放流也未能有效地提高中国对虾的自然资源量。1988～1992年我国对虾产量连续达20万吨，其中约80％是中国对虾。1993年，全国范围内220万亩的对虾养殖池爆发了病毒性流行病，产量大减。近几年来，尽管对养殖模式、养殖技术等进行了改革，但我国北方中国对虾的养殖仍然处于低迷状态。为更好地管理和开发中国对虾的遗传资源，建立完善的中国对虾优良（抗病）品种的选育计划，对中国对虾自然群体和养殖群体进行了遗传多样性评估，并对一个养殖群体进行了抗病性状的遗传育种试验。 采集中国对虾群体4个，分别为黄渤海中国对虾群体（YP），取自渤海胶州湾产卵场（36°37′N，121°E）；朝鲜西海岸群体（KP），取自朝鲜半岛西海岸中国对虾产卵场（35°34′N，126°E）；养殖群体Ⅰ（CS₁），为日照市水产研究所连续培育的第四代养殖群体；养殖群体Ⅱ(CS₂₀₁)，渤海海捕亲虾的第一代后代感染WSSV（White spot syndrome virus）爆发性流行病后的存活个体。采用RAPD（Random amplified polymorphism of DNA）技术分析YB、KP、CS₁，同工酶技术分析YP、KP、CS₁、CS₂₀₁，以确定各群体的遗传学参数。 从CS₂₀₁筛选个体大、活力强的对虾进行育种试验。CS₂₀₂和CS₂₀₃分别为感染WSSV爆发性流行病后存活的第二代和第三代群体。设计口饲毒饵法对CS₂₀₃进行人工感染，以确定连续选育的中国对虾的抗病能力。利用AFLP（Amplified fragment length polymorphisms）技术分析连续3代群体CS（201）、CS₂₀₂、CS₂₀₃的遗传多样性和遗传标记。 RAPD和同工酶的调查结果表明，中国对虾种群的遗传多样性水平低，群体内和群体间的2种分子标记都表现较高的稳定性。群体间比较分析，KP的遗传多样性最高，YB次之，CS₁最低。在用同工酶分析的4个群体中，CS₂₀₁的多态位点比例和杂合度等指标高于其它3个群体。从群体的分化指标来看，中国对 虾种群的各群体间有一定的遗传分化。 选育群淤Ca。。比未经选育的群体人工感染后死亡速度慢，相同的时问内前 者比后者的存活率高60％：病毒检测无论是选育群体和未经选育群体，60％以上 的个体感染病毒，表明选育群体对WSSV病毒具有一定的抗性。AFI。P测试的连 续选育群体的遗传多样性在 CS201和 CS202第二代之间变化不大，但CS203的遗传 多样性有明显的下降趋势；AFLP也可产生丰富的遗传标记。一 通过对实验结果的进一步分析认为：中国对虾人工育苗的过程使后代群体的 遗传多样性下降，人工培育苗种的大规模放流影响了自然群体的遗传多样性；， 分布于我国沿海的中国对虾可能由多个自然群体构成，还存在未被发现的种质资 源：中国对虾抗W SSV病毒感染是由遗传决定的，选育可提高中国对虾对W SSV 的抗性。更多还原

【Abstract】 Feneropaeneus chinensis which is mainly distributed in the Yellow Sea and Bohai Sea in China plays a very important role in both marine catching fisheries and marineculure. However,in 1990’s the production of shrimp catch and mariculture dropped dramatically. The shrimp dropped from thousand tons to hundred tons though large scales enhancement has been carried out annually by releasing of hatchery raised fries. In 1993 an epidemic outburst of viral disease in 2.2 million mu of pond-cultured shrimp brought about a great decline in production in spite of much ameliorative measure taken to improve culture mode and culture technology. The genetic diversity of natural populations and culture stocks were investigated and genetic selection for disease resistant ability were carried out in a cultured stock in order to provide information for natural resources management and exploitation.Four populations of F. chinensis,including 2 natural populations(YP and KP)and 2 cultured stocks(CS1 and CS201)were investigated. YP is collected from the spawning ground in Jiaozhou bay in the Yellow Sea(36 37’N,121 OOE),KP is collected from the spawning ground along the Korean peninsular(35 34’N,126 00 E). CS1 is the fourth generation of Bohai Sea wild population surviving the WSSV(White spot syndrome virus)epidemics in the grow-out ponds. YP,KP and CS1 were analyzed by RAPD(Random amplified polymorphism of DNA),while YP,KP,CS1 and CS201 were analyzed by isozyme.The robust and biggest individuals were selected from CS201 in selection breeding. CS202and CS203 were the second and third generation surviving the epidemic. Disease resistant ability was assessed by oral infection. The genetic variation of the three successive generations were analyzed by AFLP(Amplified fragment length polymorphism).Both the RAPD and isozyme results showed that the genetic diversity of F.chinensis was relatively low and the genetic marker showed relatively high conformity within or among populations. RAPD results showed that the genetic diversity of KP was the highest and YP was intermediate while the CS1 was the-lowest. Among the 4 populations analyzed by isozyme,the percentage of the polymorphic loci and the heterogeneity of 8201 was the highest of the 4 populations;Judged by differentiation index,genetic differentiation was found between populations. -The selected C.S203 died.more slowly than unseleeted control and the survival rate of the former was increased by 60% in the same period in the oral infection.test. The viral pathogen was discovered in more than 60% individuals in both the selected and unseleeted stocks,which implied the selection increases the disease resistant ability for WSSV. There was no obvious change in genetic diversity between the CS201 and CS202,but the genetic diversity of 8203 is lower than the former 2 stocks.It can be concluded from the experiment results that hatchery seed has lower genetic variation and large-scale hatchery seed releasing affects the genetic diversity of the natural population. The shrimp distributed along China coast in Bohai Sea and Yellow Sea may consist of more than one populations. The viral disease resistant ability of F. chinensis is proved to be genetically inherited and can be improved by genetic selection.更多还原