罗非鱼耐盐品种的选育及评价

采用混合选育方法对吉富罗非鱼和关岛红罗非鱼进行耐盐品种选育,并对其P2代繁育个体进行耐盐性能和生长性能比较研究。结果表明:P2代吉富罗非鱼和关岛红罗非鱼LS50分别比P0代提高了7.46%和8.23%,差异显著达显著水平;盐度对罗非鱼生长速度有显著影响,随着盐度的升高,吉富罗非鱼和关岛红罗非鱼的生长速度均降低;对两种罗非鱼的生长速度与盐度进行回归分析发现,2个罗非鱼品种日均增重量、瞬时增重率与盐度的线性关系都呈显著相关或极显著相关;当盐度低于9.63‰时,吉富罗非鱼的生长速度较关岛红罗非鱼快,但当盐度高于9.63‰时,关岛红罗非鱼的生长速度较吉富罗非鱼快;随着盐度的升高,吉富罗非鱼和关岛红罗非鱼的成活率均下降,而吉富罗非鱼的下降速度较快,方差分析结果表明,不同品种及其世代间成活率的差异不显著,而不同盐度间罗非鱼成活率的差异显著。

Selective breeding and evaluation of salinity tolerance tilapia

GIFT strain of nile tilapia and Guam strain of red tilapia were selected by mass selection for salinity tolerance tilapia variety.The salinity tolerance and growth performance in P2 generation were analyzed at the same time.The results showed that: compared with the P0 generation,LS50 of P2 generation of GIFT strain of nile tilapia and Guam strain of red tilapia increased 7.46% and 8.23%,respectively,and the difference was significant.Salinity had a significant effect on growth rate of tilapia,and with salinity increasing,the growth rate of GIFT strain of nile tilapia and Guam strain of red tilapia decreased.Regression analysis was conducted between growth rate of tilapia and salinity which showed that the linear relationships between average daily weight gain or instantaneous growth rate and salinity in two tilapia species were significant or highly significant correlation.When the salinity was less than 9.63‰,the GIFT strain of nile tilapia showed a better growth performance than Guam strain of red tilapia,while when the salinity was higher than 9.63 ‰,Guam strain of red tilapia showed a higher growth performance than GIFT strain of nile tilapia.With the salinity increasing,GIFT strain of nile tilapia and Guam strain of red tilapia survival rate were all decreased,and GIFT strain of nile tilapia decreased faster than Guam strain of red tilapia.The results of analysis of variance showed that the survival rate among tilapia species and generation were not significantly different,while the survival rate of tilapia among different salinities were significantly different.