山东近海褐牙鲆自然与养殖群体生化遗传结构及其遗传变异的比较分析

COMPARATIVE ANALYSIS OF BIOCHEMICAL GENETIC STRUCTURE AND VAR IANCE BETWEEN NATURAL AND CULTURED STOCKS ON THE LEFT-EYED FLOUNDER, PARALICHTHYS OLIVACEUS (T.& S.) OFF SHANDONG COASTAL WATERS

山东近海褐牙鲆自然群体活样本共 79尾 ,分别于 1 996年 5月、1 997年 1月和 1 998年 4月采自青岛近海 ;养殖群体活样本 5 2尾于 1 997年 1 2月采自山东荣成寻山养鱼场。采用水平淀粉胶和垂直聚丙烯酰胺凝胶电泳方法及 3种缓冲系统 (TC、EBT和TG)分别对自然和养殖群体的 1 5种同工酶进行生化遗传分析。结果表明 ,山东近海牙鲆自然群体的多态基因座位比例 ( 31 .0 % )和群体平均杂合度 ( 0 .0 80 2 )都明显高于养殖群体 ( 2 4 .1 % ,0 .0 788) ;在自然群体的 9个多态基因座位、养殖群体的 7个多态基因座位中 ,除了Cat(P <0 .0 5 )和Idhp - 1(P <0 .0 5 ,养殖群体中 )有显著差异、Ldh -C(P <0 .0 1 )完全偏离Hardy -Weinberg定律外 。

Expressions of 15 isozymes (LDH, MDH, MEP, IDHP, G3PDH, AK, CK, ACP, PGM, SDH, ADH, CAT, SOD, GDH and GPI) on the left-eyed flou nder, Paralichthys olivaceus, including natural and cultured stocks off Shandong coastal waters of China, were tested by horizontal starch gel and verti cal polyacrylamidae gel electrophoresis in 3 buffer systems (TC, pH=6.9; EBT, pH =8.9; TG, pH=8.3). The natural sample size is 79 live left-eyed flounders, colle cted from the coastal waters of Qingdao from May in 1996 to April in 1998. The c ultured samples (52 live left-eyed flounders) were collected from a fish farm in Rongcheng of Shandong Province in December, 1997, the parental generation of wh ich was also captured in the coastal waters of Shandong. Four tissues and organs i.e. eye, muscle, heart and liver were fetched from each of the samples after r egular morphological measurement and tested at once or stored in liquid nitrogen (-196℃) for test. The biochemical genetic structures of both stocks have been studied and compared. Altogether 29 loci in each stock were recorded, among which 9 gene loci (Ldh-A, Ldh-C,Idhp-1,Acp-1,Pgm, Sdh, Adh, Cat and Gdh) belong to the polymorphic loci in the natural stock and its mean proportion of polymorphic loci (P) was 31.0%. In the cultured stock, 7 gene loci (Ldh-A, Ldh-C,Idhp-1,Sdh, Adh, Cat and Gdh) belo ng to the polymorphic loci and its P value was 24.1%. The allelic frequencie s of both stock were also gained, with the average heterozygosities (H ) of stock being 0.0802 in natural stock and 0.0788 in cultured stock. T he values of P and H in the cultured stock were all lower t han those in the natural stock; hence the way to keep the quality of the cu ltured filial generation and then to increase fish production are very important for fish farming. The chi-square test shows that polymorphic loci but Cat (P <0.05), Idhp-1 (P< 0.05), only in the cultured population) and Ldh-C (P <0.01) in both the natural and cultured stock were in Hardy-Weinberg eq uilibrium. In the mean time, the values of observed heterozygosity (H o), H ardy-Weinberg expected heterozygosity (H e) and genetic deviate index (d ) also expressed the difference in genetic variance of these two stocks.