慢性盐度胁迫对吉丽罗非鱼(尼罗罗非鱼♀×萨罗罗非鱼♂)及其两亲本耐盐性的影响

Effects to salt tolerance of GILI tilapia(O. niloticus×S. melanotheron)and its two parents in the chronic salinity stress experiment

为深入研究养殖新品种吉丽罗非鱼[尼罗罗非鱼(♀)×萨罗罗非鱼(♂)]的耐盐性能,对吉丽罗非鱼及其两个亲本尼罗罗非鱼和萨罗罗非鱼进行了慢性盐度胁迫实验,分析了3种罗非鱼耐盐性能的差异,建立了盐度胁迫过程中死亡率与致死盐度及时间的回归模型,结果显示:(1)3种罗非鱼的耐盐能力差异显著,吉丽罗非鱼的耐盐性能接近于萨罗罗非鱼,远高于尼罗罗非鱼,耐盐胁迫时3种罗非鱼的平均致死盐度分别为57.9、66.7和18.5。(2)盐度胁迫实验中尼罗罗非鱼个体间死亡时间差异最大,萨罗罗非鱼个体之间差异最小,吉丽罗非鱼介于其间;吉丽罗非鱼和萨罗罗非鱼死亡时间都有极显著的正态负偏移,离群值和极值较多,尼罗罗非鱼有较显著正态正偏移,只有离群值,没有极值。(3)3种罗非鱼盐度胁迫实验中死亡率与死亡时间及盐度之间的回归关系更适合一元回归,吉丽罗非鱼盐度胁迫实验中死亡率(Y)与死亡时间(t)的回归模型为增长模型Y=e(-7.694+0.031t)(R2=0.979),死亡率(Y)与盐度(s)的回归模型为二次模型Y=0.542-0.037s+0.001s2(R2=0.950)。

Abstract： In order to further study salt tolerance performance of a hybrid by Oreochromis niloticus （ ♀ ） x Sarotherodon melanotheron （♂）which had been examined and approved by China National Aquaculture Variety Approval Committee as a new variety for aquaculture and named GILI tilapia in 2009, researches have been carried out to study the salt tolerance in the chronic salinity stress experiment to GILI tilapia and its two parents, the differences of salt tolerance performance of three kinds of tilapia are analysed, and the regression model between mortality of salt tolerance in the chronic salinity stress and death of time, death of salinity are established. The results of the study show that： （ 1 ） There are significant differences in capacity of salt tolerance among three kinds of tilapia, the performance of salt tolerance of GILI tilapia is close to S. melanotheron,it is much higher than O. niloticus, the average death salinity of three kinds of tilapia when they are domesticated in salt are 57.9,66.7 and 18.5 respectively. （2）There are the greatest differences of death time domesticated among individuals in O. niloticus, it is the least in S. melanotheron, it is medium in GILI tilapia. There are the most significant normal negative deviation in GILI tilapia and S. melanotheron, there are the more values of outlier and extremum, O. niloticus has a significant normal positive deviation,it has outlier values, no extremum values. （3）The regression relationships between the mortality of chronic salinity stress to salt and the death time,death salinity of three kinds of tilapia are fit for single-element regression model ,the single-element regression model between the salt tolerance mortality （Y）and the domestication time of death （t） and salinity of death （ s ） of GILI tilapia are growth model Y = e（ -7.694 ＋ 0. 031t） （ R2 = 0. 979 ） and quadratic model Y =0. 542 -0.037s ＋0. 001s2 （Rz =0. 950） respectively.