【摘要】 采用形态学方法、同工酶电泳技术和DNA分析方法对罗氏沼虾(Macrobrachium rosenbergii DeMan)缅甸野生群体(BNP种群)和浙江省养殖群体(ZCP种群)的遗传多样性进行比较分析。结果表明,两种群在外形、体色、生长等方面存在一定的差异;对罗氏沼虾11种酶的25个基因位点进行分析,得出BNP种群和ZCP种群的同工酶分析所得出的多态位点比例及平均杂合度分别为12％和:16％,0.0431和0.0501。根据同工酶的基因频率计算得两种群的遗传相似系数为0.9963,遗传距离为0.0037;22个经筛选的10bp随机引物共检测到139个RAPD位点,BNP种群的多态位点比例和遗传多态度(Ho)分别为33.81％和0.0940,高于ZCP种群的30.22％和0.0780,两个群体的平均遗传多态度(Hpop)为0.0860,90％以上的遗传变异是在群体内检测到的。根据RAPD扩增的基因频率得出两群体间的遗传距离为0.1206。无论是同工酶电泳结果还是RAPD分析结果,都表明罗氏沼虾缅甸野生群体的遗传多样性高于浙江养殖群体,说明人工养殖会导致罗氏沼虾遗传多样性的下降。结果还表明,罗氏沼虾群体遗传多样性水平欠丰富,因此需要对罗氏沼虾群体实行科学的管理。更多还原

【Abstract】 Genetic diversity analysis on the two populations of giant freshwater prawn ( Macrobrachium rosenbergii De Man) was investigated by morphologic method,enzyme electrophoresis and RAPD method. The samples of the wild population were introduced from Burma naturai waters in May,2002. The live materials of the cultured population were collected from Haining, Zhejiang. Morphological characteristics of the samples were measured using traditional methods.Eleven isozymes (LDH,SOD,G6PDH, ADH, ME,SDH, MDH,GDH,AKP,AGP and EST) were analyzed by vertical polyacrylamide gel electrophoresis(PAGE). The buffer system: Tris-Gly(pH 8.3) , voltage: 120 V 30 - 40 min in concentrated gel(3% ,pH 6.7) ,200 V 4 h in separated gel(7. 5 %, pH 8.9). The results showed that there were some differences between the two populations on their morphology,body color and growth. The eleven enzymes were coded by 25 genetic loci, of which four were found polymorphic in the wild population, while three in the cultured population. The proportion of polymorphic loci and mean hetrozygosity of the wild and cultured population were 16% and 12% ,0.050 1 and 0.043 l,respectively. The genetic similarity and genetic distance of the two populations were 0.996 3 and 0.003 7 calculated by allelic frequencies.Random amplified polymorphic DNA (RAPD) technigue was also employed to detect the genetic varia-tion of 20 inds from each population. The RAPD reactions were performed by 94 ℃ predenaturation for 4 min, 40 cycles of 94 ℃ denaturation for 1 min, 36 ℃ annealing for 1min and 72 ℃ polymerization for 2 min.Complete extension was done by 72 ℃ for 8 min. Each primer used for the detection could produce 2-10 molecular markers. Amplification with 22 selected primers produced 139 distinctive and reproducible bands varying in length from 100 to 3 500 bp. There were 47 and 42 bands polymorphic,and the proportions of polymorphic loci in the wild population and the cultured were 33.81% and 30.22%, respectively. The Shannon index Ho of the wild population and the cultured one were 0.094 0 and 0.078 0 respectively. The mean genetic diversity of the two populations is 0.086 0, and more than 90% of which were detected among the populations. The genetic distance between the two populations was 0.120 6 calculated by the frequencies of RAPD loci.The results from enzymes analysis and those from RAPD analysis showed that the genetic diversity of Burma wild population of M. rosenbergii was higher than that of Zhejiang cultured population. But, com-pared with other shrimps,the genetic diversity in the two populations of M. rosenbergii was low. The ap-propriate measurements should be conducted in the shrimp aquaculture. The way to improve the germplasm resource of the cultured M. rosenbergii was also discussed.更多还原