吉富品系尼罗罗非鱼的选育效果分析

Study on the Selection Effects of GIFT Strain of Nile Tilapia,Oreochromis niloticus

采用闭锁群体继代选育的方法对吉富品系尼罗罗非鱼(GIFT strain of Nile Tilapia)进行提纯选育,并利用选育获得的尼罗罗非鱼亲本作母本和奥利亚罗非鱼作父本进行杂交生产子一代,再对子一代开展网箱养殖对比试验,以养殖试验的结果来评价选育尼罗罗非鱼(Oreochromis niloticus)的效果。结果表明:(1)选留系后备♀亲本选留数量及留种率都有了很大的提高;(2)"吉奥"杂交组合的产苗量和雄性率都有了不同程度的提高;(3)经过选育的"吉奥"罗非鱼的生长性能优于对照组;生长速度增加明显;头部比例有变小的趋势;(4)试验组"吉奥"罗非鱼的主要经济指标均比对照组有所提高,而饵料系数比对照组有所下降。以上结果表明,"吉奥"罗非鱼的选育效果良好,可为"尼奥"罗非鱼的苗种生产提供亲本保障。

In this study,the closed nuleus breeding method was carried out on the selective breeding in Nile tilapia with main selective traits as growth rate,stripe identity in caudal fin and body shape,et al.,and the selection efficiencies of the early generations（second generation） were evaluated.The results were as following：（1） The percentage of females suitable for selective breeding in P2 generation of ＂Ji-Ao＂ tilapia was much higher than that in the foundation（P0） and first（P1） generation;（2） The hatchlings and the male rate in the crosses of ＂Ji-Ao＂ tilapia improved greatly;（3） Thegrowth performances in selection generation（SG） population after different culturing duration were higher than that in control generation（CG）;The growth speed in SG was much faster than that in CG group;The percentage of fish with ratio of head length over standard length was higher in the SG population of ＂Ji-Ao＂ tilapia than its CG population;（4） The main economic indicators in each test group of ＂Ji-Ao＂ tilapia were higher than that in their corresponding control group,and the feed transfer efficiency was lower than that in control group.These indicated that the selective effects of ＂Ji-Ao＂ tilapia were good and could offer enough parental fish for reproduction of juvenile fish in ＂Ni-Ao＂ tilapia.