中间球海胆抗病家系的筛选及其生长性能分析

Selection of disease-resistant family and evaluation of growth performance in sea urchin Strongylocentrotus intermedius

为筛选中间球海胆Strongylocentrotus intermedius抗病家系并分析其生长性能,在建立34个中间球海胆全同胞家系的基础上,采用自然感染的方法对海胆进行病变综合征、掉棘病和黑嘴病的感染并测量这3种疾病下海胆的存活率,通过对不同疾病下的存活率进行加权求和构建了复合抗病指数(CDRI),根据存活率和抗病指数排名筛选出抗病家系,分析抗病家系在幼胆期(7~9月龄)和在不同水温环境下(常温和低温)养成期(14~17月龄)的体质量特定生长率(SGR)与易感家系、所有家系间的差异,并筛选出抗病速生家系。结果表明:病变综合征、掉棘病和黑嘴病自然感染下,各家系的存活率分别为30.9%~95.5%、10.0%~100.0%和5.6%~84.2%,不同家系下海胆的存活率有显著性差异(P<0.05);筛选出F7211-1等家系具有较强的抗病变综合征能力,F7214-1等家系具有较强的抗掉棘病能力,F7214-1等家系具有较强的抗黑嘴病能力;各家系的复合抗病指数为0.29~0.78,家系F7209-1等具有较高的复合抗病能力;相对于选择特定抗病家系,选择复合抗病家系会对幼胆期和不同水温养殖下的养成期生长速度带来更稳定的正向选择差;无论成胆期养殖于常温池还是低温池,F7211-1、F7203-2、F7209-1和F7214-1等家系均兼具抗病和速生的能力,可从中选择种胆用于后代抗病速生群体的培育。研究表明,家系选择可应用于中间球海胆的抗病育种,通过构建复合抗病指数可实现对抗病和生长速度的复合选择。

The growth performance including body weight specific growth rate(SGRs)and survival rate were measured in 10-14 months old sea urchin Strongylocentrotus intermedius in 34 full-sib families naturally challenged by syndrome disease,spine detaching disease and black mouth disease at water temperature of normal and low,respectively,to select disease-resistant and fast-growth families in sea urchin during juvenile(7-9 month old)rearing and subadult(14-17 month old)period via comprehensive disease resistance index(CDRI)calculated by weighted summation.The results showed that survival rates were ranged from 30.9%to 95.5%in the sea urchin challenged by syndrome disease,from 10.0%to 100.0%in the sea urchin challenged by spine detaching disease and from 5.6%to 84.2%in the animals infected with black mouth disease,with very significant difference in various families(P<0.01).There were higher resistances against syndrome disease in selectively bred family F7211-1,against spine detaching disease in family F7214-1 and against black mouth disease in family F7214-1,with higher CDRIs ranging from 0.29 to 0.78 in the selectively bred families,with the maximum in family F7209-1.The selection of comprehensive disease-resistant families showed more stable positive selection differential on both SGRs in juvenile stage and in adult stage culture in different seawater temperature compared with selection of specific disease-resistant families.Adults in families F7211-1,F7203-2,F7209-1 and F7214-1 showed combined abilities of disease-resistant and fast-growing at both normal and low temperature,and breedstocks were selected from these families to produce disease-resistant and fast-growth stock generations.The findings indicated that family selection can be used to improve disease resistance of sea urchin,and to achieve combined selection on disease resistance and growth rate based on CDRI.