来曲唑对棘胸蛙生长、性比及性激素水平的影响  

Effects of Letrozole on Growth,Sex Ratio and Sex Hormone Level of Quasipaa spinosa

作　　者：张浓 李娟 向建国[1] 潘望城 ZHANG Nong;LI Juan;XIANG Jianguo;PAN Wangcheng(College of Animal Science and Technology,Hunan Agricultural University,Changsha 410128,China;Changde Dabeinong Feed Co.,Ltd.,Changde 415400,China)

机构地区：[1]湖南农业大学动物科学技术学院,湖南长沙410128 [2]常德大北农饲料有限公司,湖南常德415400

出　　处：《云南农业大学学报（自然科学版）》2022年第6期979-984,共6页Journal of Yunnan Agricultural University:Natural Science

基　　金：湖南省现代农业产业技术体系项目(5026401,0319085)。

摘　　要：【目的】研究来曲唑对棘胸蛙(Quasipaa spinosa)生长、性比及性激素水平的影响,为棘胸蛙全雄育种提供参考。【方法】投喂不同来曲唑含量(20、100、400和1000 mg/kg)的饲料(分别记为L20、L_(100)、L_(400)和L_(1000)组)诱导棘胸蛙蝌蚪雄性化,并设置对照组(CK组),投喂周期为90 d。在20~70日龄期间,每隔10 d测定各组蝌蚪的性激素[雌二醇(E2)和睾酮(T)]水平;之后正常饲养至变态完成,测定各组幼蛙的生长指标和性比。【结果】(19±1)℃养殖水温下,棘胸蛙雄性率较低,CK组雄性率仅为33.33%。投喂不同来曲唑含量的饲料均能显著提高棘胸蛙的雄性率(P<0.05),L_(20)、L_(100)、L_(400)和L_(1000)组的雄性率分别为58.49%、55.26%、48.84%和56.82%。不同来曲唑含量的饲料对变态幼蛙的体长、头长、头宽、前臂及手长、后肢全长和肝体比等生长指标均无显著影响(P>0.05)。从原始性腺到性腺分化结束期间(20~70日龄),与CK组相比,各来曲唑含量处理组的E_(2)和T水平总体上均显著上升(P<0.05);精巢分化期间(40~50日龄),各来曲唑含量处理组的T水平均显著高于CK组(P<0.05),是诱导雄性化的关键。【结论】本试验条件下,来曲唑可显著提高棘胸蛙后代雄性率,但对棘胸蛙生长无影响。[Purpose]To study the effects of letrozole on the growth,sex ratio and sex hormone levels of Quasipaa spinosa,providing reference for the whole male breeding of Q.spinosa.[Methods]Feeding letrozole(20,100,400 and 1000 mg/kg)with different contents(recorded as L_(20),L_(100),L_(400)and L_(1000)group,respectively),and the control group(CK group)was set up,the feeding cycle was 90 days.During the period of 20-70 days after hatching,the levels of sex hormones[estradiol(E_(2))and testosterone(T)]of tadpoles in each group were measured every 10 days.After normal feeding until metamorphosis completed,the growth indicators and sex ratio of each group were measured.[Results]The male rate of Q.spinosa was low at(19±1)°C,the male rate of CK group was only 33.33%.Feeding different contents of letrozole could significantly improve the male rate of Q.spinosa(P<0.05),the male rates of L_(20),L_(100),L_(400)and L_(1000)groups were 58.49%,55.26%,48.84%and 56.82%,respectively.Different contents of letrozole had no significant effect on snout-vent length,head length,head width,forearm and hand length,hind limb length and hepatosomatic index of young frogs(P>0.05).From primitive gonad to the end of gonad differentiation(during 20-70 days after hatching),compared with the CK group,the E2 level and T level of each letrozole treatment group was significantly increased(P<0.05).During testis differentiation(during 40-50 days after hatching),the T level of each letrozole treatment group was significantly higher than that of CK group(P<0.05),which was the key to induce maleation.[Conclusion]In this experiment,letrozole has no effect on the growth of Q.spinosa,but it can improve the male rate of offspring of Q.spinosa sig-nificantly.

关 键 词：棘胸蛙 来曲唑 生长 性比 性激素水平 

分 类 号：S917.4[农业科学—水产科学]