有机磷农药乐果对家蚕子代生殖功能的影响  

Effects of organophosphate pesticide Dimethoate on reproductive function of silkworm progeny

作　　者：孙曼萁 魏欣[1] 石敏 朱勇[1] SUN Man-qi;WEI Xin;SHI Ming;ZHU Yong(College of Sericulture,Textile and Biomass Sciences,Southwest University,Chongqing 400715,China;Chongqing Wanzhou No.1.Senior High School,Chongqing 400715,China)

机构地区：[1]西南大学蚕桑纺织与生物质科学学院,重庆400715 [2]重庆市万州第一中学,重庆万州404000

出　　处：《蚕学通讯》2021年第1期19-29,共11页Newsletter of Sericultural Science

基　　金：2019年西南大学大学生训练项目(x201910635194)

摘　　要：为探讨有机磷农药乐果导致家蚕慢性中毒后对子代生殖功能的影响,以<LD 50的乐果溶液处理桑叶饲喂家蚕幼虫,调查供试家蚕正常交配繁殖子代的生殖发育情况和抗氧化酶活性及酶蛋白编码基因的转录变化。通过苏木精伊红染色法观察到添食乐果后家蚕雌、雄幼虫生殖腺的形态结构发生了变化,表现为细胞破碎,细胞内空泡增大,生殖细胞数目相对减少,且随乐果浓度的增加,生殖腺损伤越严重,自交组的幼虫生殖腺受损则更为严重。随着添食乐果的浓度增加,供试家蚕子代生殖腺中的过氧化氢酶(CAT)活性都出现先降低后升高的趋势,而超氧化物歧化酶(SOD)的活性在杂交组子代逐渐上升,在自交组子代逐渐下降,cat和sod基因mRNA转录水平则均呈现显著下降的趋势;卵巢发育相关基因Ovo、Vg和Sxl-S的mRNA转录水平均呈现下降趋势,精巢发育相关基因Achi、Aly、Vlg也出现下调表达,且自交组的下调水平更为明显。研究结果表明,低浓度乐果导致5龄幼虫慢性中毒后,其正常繁殖产生子代的生殖发育也会受到严重影响,即乐果对亲代的毒性会延续到子代,且自交组子代受影响更大。In order to investigate the effect of dimethoate on the progeny function of silkworm after chronic poisoning,mulberry leaves treated with dimethoate solution<LD 50 were fed to silkworm larvae.And then,the reproductive development of silkworm progeny during normal breeding,the activity of antioxidant enzymes and the transcription changes of enzyme encoding genes were investigated.Hematoxylin eosin staining method was employed to observe the silk gland tissue after feeding dimethoate to silkworm larvae.And the results indicated the changes of male and female gonad in morphological structure,cell disruption,increase of cell vacuoles,and the decreased numbers of reproductive cells.In addition,with the increase of the concentration of dimethoate,gonad damage became more serious,and the gonad damage of self-crossing group larvae became more serious.As the concentration of dimethoate increased,the catalase(CAT)activity in the gonads of the tested silkworms showed a trend of first decreasing and then increasing.While the activity of superoxide dismutase(SOD)gradually increased in the offspring of the hybrid group,and decreased gradually in the offspring of the self-bred group.The mRNA transcription levels of cat and sod genes both showed a significant downward trend;the ovary development related genes Ovo,Vg and Sxl-S and the testis development related genes Achi,Aly and Vlg were also down-regulated,and the down-regulated level was more obvious in the self-crossings group.The results indicated that the low concentration of dimethoate caused the chronic poisoning of the fifth instar larvae and the normal reproduction and reproductive development of the progeny would be seriously affected.Above all,the toxicity of dimethoate to the parents would continue to the progeny,and the effect of dimethoate on the progeny of the self-crossing group was more significant.

关 键 词：乐果 半数致死量 家蚕 杂交 自交 生殖毒性 

分 类 号：S881.2[农业科学—特种经济动物饲养]