凡纳滨对虾群体杂交与自交 F1低溶氧与高氨氮耐受性比较

利用6个遗传背景不同的凡纳滨对虾(Litopenaeus vannamei)群体,通过群体间自交与杂交建立了8个交配组合。对不同交配组合F1,在幼虾和成虾阶段,进行低溶氧与高氨氮48 h胁迫试验,比较不同交配组合群体在不同生长阶段的高氨氮与低溶氧耐受性。结果显示,低溶氧胁迫,YH♀×ZX♂、SS♀×SS♂、HD♀×YH♂交配组合幼虾存活率分别为76.23%、74.61%、74.38%,显著高于其他交配组合存活率(P0.05),成虾的存活率分别为83.08%、65.57%、71.12%,可作为耐低溶氧优良品系选育的候选材料;高氨氮胁迫,YH♀×KN♂、HD♀×YH♂、YH♀×ZK♂交配组合幼虾存活率分别为97.71%、86.43%、80.01%,显著高于其他交配组合(P0.05),成虾存活率分别为85.53%、74.18%、69.23%,可作为耐高氨氮优良品系选育的候选材料;HD♀×YH♂交配组合低溶氧与氨氮耐受性均较好,但不同交配组合低溶氧与氨氮耐受性间相关性检验不显著(P0.05)。研究发现,亲本中雌虾来源为YH,子代低溶氧耐受性优良,推断抗低溶氧性状为母系主导遗传;对虾低溶氧的耐受性随着生长发育的进行而降低,高氨氮耐受性随着生长发育的进行而增强;各交配组合高氨氮和低溶氧耐受性,在幼虾阶段和成虾阶段均呈极显著相关(P0.01),表明凡纳滨对虾低溶氧与高氨氮耐受性适宜在幼虾阶段进行遗传评估。

A comparative study of hypoxia and high-ammonia resistance between Litopenaeus vannamei inbred and hybrid offspring at different stages

We conducted a comparative study of hypoxia and high-ammonia resistance in Litopenaeus vannamei after 48 hours of stress in different mating combinations of the F1 generation at the juvenile and adult stages. We set up eight mating combinations of inbred and hybrid L. vannamei with six different genetic backgrounds. The results show that the survival rates of the YH× ZX, SS × SS, and HD × YH juvenile shrimp mating combinations were 76.23%, 74.61%, and 74.38%, which were significantly higher than those of the other mating combinations (P<0.05). Survival rates of adult shrimp under hypoxic stress were 83.08%, 65.57%, and 71.12%. Thus, these adults could be used as candidates for hypoxia-resistant breeding. Survival rates of the YH × KN, HD × YH, and YH × ZK juvenile shrimp mating combinations were 97.71%, 86.43%, and 80.01%, which were significantly higher than those of the other mating combinations (P<0.05). Survival rates of the adult shrimp under high-ammonia stress were 85.53%, 74.18%, and 69.23%. Thus, these adults could be used as candidates for high-ammonia resistant breeding. Hypoxia and high ammonia resistance of the HD× YH mating combination was high, but the correlation between hypoxia and high-ammonia resistance in the different mating combinations was not significant. We found that if a female parent originated from the YH group, its offspring were also hypoxia resistant, suggesting that the hypoxia resistance trait is a maternal dominant genetic trait. Hypoxic resistance decreased during the growth and development of the shrimp. The correlation between mating combinations of juvenile and adult shrimp for hypoxic stress and high-ammonia stress was highly significant (P<0.01). These results suggest that the hypoxia and high-ammonia resistance traits of L. vannamei should be evaluated at the juvenile stage. This study lays the foundation for developing and culturing hypoxia- and high ammonia-resistant L. vannamei strains.