牙鲆抗淋巴囊肿病家系选育及生长和抗病性能分析

Analysis of growth and lymphocystis disease resistance of selected breeding families of Japanese flounder(Paralichthys olivaceus)

为了选育抗淋巴囊肿的牙鲆(Paralichthys olivaceus)新品种,2015年建立了5个普通家系(C1~C5)、3个雌核发育家系(G1、G2、G3)和1个对照组,在淋巴囊肿病高发养殖场进行自然染毒实验,统计各家系的抗病保护率。同时对各家系120 d、180 d、240 d和300 d时的生长性状进行跟踪测量和比较。结果表明,各家系牙鲆在不同时期有各自不同的生长规律,呈现出家系间生长规律的不一致性。但在所有家系中,家系G2各个时期的生长表现始终排名靠前。390 d统计抗病保护率的结果显示,对照组的抗病保护率只有59.57%,而经选育所有实验组的抗病保护率都在60%以上,最高达97.20%(家系G2)。但总体上,390 d时牙鲆淋巴囊肿抗病和患病个体间体重和体长差异均不显著;体重、体长与抗病保护率为正相关,但相关性均不显著。家系G2抗病个体的平均体重显著高于患病个体(P<0.05)。以G2家系为基础,继续进行选育,有望获得牙鲆抗淋巴囊肿速生新品种。

Lymphocystis disease is a viral infection caused by lymphocystis disease virus, which has serious im- pacts on the aquaculture industry, resulting in heavy losses. In order to select new varieties of Japanese flounder （Paralichthys olivaceus） resistant to lymphocystis disease, eight experimental groups and one control group were established in 2015. The exposure experiment was conducted on one farm with high incidence of lymphocystis di,~ease, and the protection rate of each group was determined. At the same time, the growth traits of each group at 120 d, 180 d, 240 d, and 300 d were measured and compared. The results showed that there were different growth patterns for each group in different periods, showing inconsistent growth patterns among groups. However, in all the groups, the growth performance of group G2 was always ranked the highest for each period. The results also showed that the disease resistance protection rate of the control group was only 59.57%, while the disease resis- tance protection rate of all the tested groups was above 60%, reaching up to 97.20% for group G2. From the over- all analysis, there were no significant differences in the body weight and body length between the disease resistant or sensitive individuals at 390 d of age. The body weight and body length were positively correlated with disease resistance protection rate, while their effects were not significant （P〉0.05）. However, the mean body weight of disease-resistant individuals in group G2 was significantly higher than that of disease-sensitive individuals （P〈 0.05）. Based on the group G2, it is expected that a new variety of fast-growing lymphocystis disease-resistant Japanese flounder could be developed.