不同罗氏沼虾种群形态差异的比较研究

Morphological variations analysis among eight populations of cultivated and wild and hybridized in Macrobrachium rosenbergii

采用3种多元分析方法，对8个罗氏沼虾（Macrobrachium rosenbergii）种群（浙江养殖种群，缅甸引进种群及6个不同组合杂交种群）的12个形态比例参数进行比较研究。聚类分析和主成分分析法对雌、雄虾的分析结果表明，6个杂交种群的形态较为接近，而与养殖种群和引进种群的趋异程度逐渐增加。构建的5个雌体主成分中，方差贡献率分别为主成分（1）26．191％、主成分（2）16．036％、主成分（3）13．309％、主成分（4）10．769％、主成分（5）10．166％，累积贡献率为76．471％。相应地，雄体的方差贡献率分别为主成分（1）25．206％、主成分（2）20．277％、主成分（3）16．985％、主成分（4）13．222％、主成分（5）8．945％，累积贡献率为84．634％。判别分析结果显示，8种群之间的形态参数之间有极显著的差异（P〈0．01）；8种群雌体判别函数的判别准确率P1为60．03％～100．00％，P2为33．30％～100％，综合判别率为92．1％；雄体判别准确率P1为20．00％～100．00％，P2为20．00％～100％，综合判别率为86．4％。其中判别函数对养殖种群，缅甸引进种群和“反交正回交”3个种群的判别准确率较高。综上所述，养殖种群和引进种群在形态上已经出现了明显的分化，并独立成为2个不同的种群；其他杂交种群由于同时综合了养殖种群和引进种群两者的相关性状，形态上没有呈现显著的差异（P〉0．05）。[中国水产科学，2006，13（4）：530-535]

Much debate has surrounded the genetic diversity of shrimp. Garvca and Acivar have analyzed the genetic variation of Litopenaeus vannamai of different populations and filtrated differential markers successfully; Song Linsheng has investigated the genetic structure of the natural population and hatchery stock of Penaeus Japonica, and found that the mean proportion of polymorphic amplified fragments of natural population was higher than that of hatchery stock . The research about genetic diversity has also been made in other animal species such as Sinonovacula const ricta Larnarck,Paralichthys olivaceus ,Eriocheir sinensis and Siniperca chuatsi Basilewsky. Macrobrachium rosenbergii , which is subjected to Macrobrachium , Palaemonidae, Crustacea, is a very important kind of freshwater edible shrimps in China and the economic value is prominent. In recent years, it has suffered degeneration in its resource, and its wild and cultivated stocks and their genetic diversity has been threatened to some extent due to overfishing and inbreeding. So it is the time to investigate the variation of Macrobrachium rosenbergii of different populations. Based on 12 morphological proportional characters of Macrobrachium rosenbergii, three multivariation analysis methods （cluster analysis, prinpical component analysis and discriminant analysis） were adopted to comparably investigate the morphological variation among eight populations （1 cultivated, 1 wild and 6 hybridized populations）. The results of cluster analysis and principal component analysis indicated that the morphological characters were similar among the six hybridized populations. But quite different from that of cultivated and Burma introduced population. In the principal component analysis of the female populations, five principal components were constructed, the contributory ratio of the first principal component was 26.191%, the second, the third, the fourth and the fifth was 16.036%, 13.309%, 10.796%, and 10. 166% respectively, the cumulative contributory ratio was 76.471%. Accordingly, for the male populations, five principal components were also constructed, their contributory ratios were 25.206%, 20.277%, 16.985%, 13.222% and 8.945% respectively, the cumulative contributory ratio was 84.634%. The result of discriminant analysis revealed that there were significant differences among most of the eight populations （P〈 0.01）. The identification accuracy of female was 60.03% - 100.00% （P1） and 33.30% - 100 % （P2）, the total discriminant accuracy was 92.1%. The identification accuracy of male was 20.00 % - 100.00% （P1） and 20.00% - 100.00% （P2）, the total discriminant accuracy was 86.4%. The results showed that there were distinct diversities between the cultivated population and Burma introduced population, which have formed two independent populations; but other six hybridized populations （with the exception of the population of B- ＋ ） did not appear distinct diversities, which was because these populations were the integrative offspring of the two populations mentioned above. [Journal of Fishery Sciences of China,2006,13（4） ：530 - 535]