凡纳滨对虾选育群体与近交群体、引进群体生长和存活性能比较

为研究凡纳滨对虾选育群体与近交群体、引进群体的生长和存活性能差异,本实验利用家系标准化构建方法构建了选育群体、引进群体和近交群体家系,开展共同养殖环境下的生长和存活性能测试实验,分析了三个群体的体质量、存活率和近交衰退情况.结果表明,选育群体收获体质量与引进群体、全同胞近交一代群体体质量均存在显著差异(P＜0.05),第60天收获时,选育群体比引进群体的体质量提高7.11％,比近交群体的体质量提高20.01％;选育群体和引进群体内不同家系生长速度存在较大差异,选育群体中增重最快的家系为6012家系,绝对增重率为0.29 g/d,比所有家系绝对增重率均值高31.82％,比增重最慢的家系高61.11％,引进群体中绝对增重率和特定生长率均最高的家系为6008家系,分别为0.33 g/d和3.17％/d,比所有家系均值分别高65％和33.19％,比增重最慢的家系分别高230％和128.06％;存活率方面,选育群体与引进群体差异不显著(P＞0.05),但与近交群体存在显著性差异(P＜0.05),存活率提高12.74％.近交衰退结果显示,与选育群体及引进群体相比较,近交群体收获体质量生长性状的实际衰退百分比分别为16.68％和10.76％,近交系数每增加10％所引起的近交衰退系数分别为-6.60％和-4.30％,且选育群体与近交群体在收获体质量上差异显著(P＜0.05);存活率性状也出现了一定程度的近交衰退,实际衰退百分比分别为11.30％和10.54％.本研究结果可为凡纳滨对虾的后期选择育种工作提供数据参考.

Comparison of growth and survival performance among selected population, imported population and inbreeding population in Litopenaeus vannamei

The present study explored the differences in growth,survival and inbreeding depression among selected population,inbreeding population and imported population.Inbreeding population was constructed by full-sib mating of selected population in Litopenaeus vannamei.A standard procedure was used in family construction.Individuals of three populations were tested in the same environment.The growth experimental results showed that,body weight of selected population was significantly higher than those of inbreeding population and imported population(P<0.05).At day 60,body weight of selected population increased by 7.11% and 20.01%,compared with those of imported population and inbreeding populations.Different growth performance was observed among different families and in different population.The body weight of 6012 was biggest in selected population,AGR and SGR is 0.29 g/d and 31.82% higher than the mean of the families,and 61.11% higher than that of the lowest.And the body weight of family 6008 was biggest in imported population,AGR and SGR is 0.33 g/d and 3.17%/d,which was 65% and 33.19% higher than the mean of the families,and 230% and 128.06% higher than that of the lowest.The survival results indicated that the difference of survival between selected population and imported population was not significant(P>0.05),but that was significant(P<0.05)between selected population and inbreeding population,12.74% higher than inbreeding population.Full-sib matings revealed that the amount of inbreeding depression of body weight were 16.68% and 10.76%,and inbreeding depression of survival were 11.30% and 10.54%,compared with selected population and imported population.The estimated average inbreeding depression coefficient of body weight was -6.60% and -4.30% per 10% increase of inbreeding coefficient.These results suggest that selection works well in the breeding program of Litopenaeus vannamei,and inbreeding especially full-sib matings should be avoided in the future breeding programs.