牙鲆家系4 个选育性状的测定与分析

为了研究牙鲆(Paralichthys olivaceus)不同选育性状之间的相关性,2009年建立了38个牙鲆实验家系和1个养殖场对照组。选取其中33个家系和对照组进行鳗弧菌感染实验并对存活个体进行荧光标记后混合养殖在2个水泥池中,其中一个混养池在平均400日龄时暴发了淋巴囊肿病(Lymphocystis Disease,LD),LD发病率为62.4%,包括16个家系和对照组。从这些家系中筛选出4个发病率低于40.0%的抗病家系(F0939,F09104,F0915,F0908)。另外,在4~5月龄时,从每个家系中平均选取100尾鱼进行荧光标记后混合养殖,580日龄时测定这些家系的养殖存活率和体重,平均养殖存活率为32.0%,将7个养殖存活率高于55.0%的家系定义为高养殖存活率家系(F0908,F0975,F0990,F09125,F0927,F09119,F0905)。对牙鲆LD的抗病个体和易感个体的体重和全长进行卡方检验,发现抗病个体的体重和全长均显著高于易感个体(P0.01),同时分析牙鲆各个家系的LD发病率与发病时的体重和全长的相关性,结果显示牙鲆各个家系LD发病率与发病时体重和全长均呈强负相关(r–0.6)。对牙鲆家系鳗弧菌感染存活率、LD发病率、580日龄的养殖存活率和体重这4个性状两两之间进行相关性分析,发现LD发病率与580日龄的体重呈强负相关(r=–0.790);鳗弧菌感染存活率与养殖存活率之间为弱正相关(r=0.371);其他性状两两之间不存在显著相关性(–0.092≤r≤0.185)。本研究共筛选到了4个牙鲆LD抗病家系和7个高养殖存活率家系,并揭示了4个牙鲆选育性状之间的相关性,为培育速生多抗的牙鲆新品种提供了遗传材料和理论依据。

Determination and analysis of 4 breeding traits in Japanese flounder(Paralichthys olivaceus) families

) is an important commerciallycultured fish in China, Japan, andKorea. The rapid development of the Japaneseflounder aquaculture has led to problems with various diseases that havereducedgrowth rates and caused huge economic loss. One way to address these problemsis to cultivate strains withcharacteristics such as high growth performance,breeding survival rates, and disease resistance. For this purpose, 38familiesand a control group were established in 2009. Four to five months afterhatching, 33 of the 38 families and thecontrol group were selected for exposureto . The surviving individuals were marked with fluorescent-dyeand cultivated in two cement pools. Four hundred days after hatching,lymphocystis disease (LD) broke out inone of the pools containing 16 familiesand the control group. The average rate of incidence was 62.4%; those families(Families8, 15, 39, and 104) with disease incidence below 40% were defined asdisease-resistant. At the same time, 100fish selected from each family weremarked with fluorescent-dye and cultivated in different cement pools. Roughly580 dafter hatching, breed survival rate (580-BSR) and body weight (580-BW)were determined. For the 38 families, the average580-BSR was 32.0%. There wereseven families (Families 5, 8, 27, 75, 90, 119, and 125) with a 580-BSR above55%,and they were defined as high breed survival rate families. Notably, in 6 ofthe 7 families, at least one parent wasderived from F0750 (Family 50established in 2007), suggesting that individuals from F0750 may effectivelyimprove580-BSR. Chi-square tests indicated that body weight (400-BW) and totallength (400-TL) of the resistant group weresignificantly higher than those ofthe susceptible group (