克氏原螯虾三群体双列杂交组合生长性能和耐干露能力比较分析

Comparative analysis of growth performance and desiccation resistance of three-population diallel hybrid combination of Procambarus clarkii

以遗传多样性高、生长快的江苏滆湖、江苏建湖和安徽芜湖3个克氏原螯虾优异种质群体进行双列杂交试验,得到6个杂交组[滆湖♀×建湖♂(GJ)、建湖♀×滆湖♂(JG)、滆湖♀×芜湖♂(GW)、芜湖♀×滆湖♂(WG)、建湖♀×芜湖♂(JW)、芜湖♀×建湖♂(WJ)]和3个自交组[滆湖♀×滆湖♂(GG)、建湖♀×建湖♂(JJ)、芜湖♀×芜湖♂(WW)],对9个组合生长性能和生态适应性比较分析,结果表明:(1)养殖周期内,WW和JJ组合雌雄个体体质量特定增长率、增重率均显著大于其余组合;除GJ和JG外其余组合雄性个体体质量特定增长率、增重率显著大于雌性,3—5月各杂交组生长性状均未见杂种优势;(2)随养殖时间的增加,9个群体克氏原螯虾头胸甲长/体长、腹部长/体长变化明显,头胸甲长/体长逐渐增加,腹部长/体长逐渐减小且5月雌雄个体间出现分化,雌性腹部长占比显著大于雄性。头胸甲宽/体长、腹部宽/体长、尾节长/体长仅4月有明显增加;(3)干露24 h各组虾开始出现死亡,48 h各组存活率出现显著分化,48 h时WW组合存活率显著大于其余组合,GJ和JG两个正反交组在耐干露能力方面呈现出杂种优势。本研究发现克氏原螯虾种质混杂一定程度限制了生长性状杂种优势,但抗逆性表现出杂种优势,适当杂交再选育是重要的育种策略,克氏原螯虾生长和腹部长占比呈明显雌雄二态性,单性育种也是重要方向。

This study conducted diallel hybridization experiments on three excellent populations of Procambarus clarkii,namely Gehu,Jiangsu;Jianhu,Jiangsu;and Wuhu,Anhui,with high genetic diversity and fast growth.Six hybrid groups were obtained[Gehu♀×Jianhu♂(GJ),Jianhu♀×Gehu♂(JG),Gehu♀×Wuhu♂(GW),Wuhu♀×Gehu♂(WG),Jianhu♀×Wuhu♂(JW),Wuhu♀×Jianhu♂(WJ)],and three self crossing groups[Gehu♀×Gehu♂(GG),Jianhu♀×Jianhu♂(JJ),Wuhu♀×Wuhu♂(WW)].A comparative analysis was conducted on the growth performance and ecological adaptability of 9 combinations.The results showed that:(1)During the breeding cycle,the weight gain and weight gain rate of both male and female individuals in the WW and JJ combinations were significantly higher than those in the other combinations(P<0.05);Except for GJ and JG,the weight gain and growth rate of male individuals in all combinations were significantly higher than those in females.From March to May,no heterosis was observed in the growth traits of each hybrid group;(2)With the increase of breeding time,there were significant changes in the length/body length of the head and chest armor,as well as the length/body length of the abdomen in the 9 populations of crayfish.The length/body length of the head and chest armor gradually increased,while the length/body length of the abdomen gradually decreased.In May,there was differentiation between male and female individuals,and the proportion of female abdomen length was significantly higher than that of male.The ratio of head to chest armor width/body length,abdominal width/body length,and tail segment length/body length only showed a significant increase in April;(3)After 24 hours of dry dew,each group of shrimp began to die,and at 48 hours,the survival rate of each group showed significant differentiation.At 48 hours,the survival rate of the WW combination was significantly higher than that of the other combinations.The GJ and JG cross groups showed heterosis in terms of dry dew tolerance.This study found that the mixed germplasm of crayfish limited the heterosis of growth traits to a certain extent,but showed heterosis in stress resistance.Proper hybridization and re-selection are important breeding strategies.The growth and abdominal length ratio of crayfish showed obvious male and female dimorphism,and single sex breeding is also an important direction for future research.