Ni胁迫对斜纹夜蛾幼虫包囊反应的影响

Effects of nickel exposure on encapsulation rate of hemocytes of Spodoptera litura Fabricius larvae

将不同浓度Ni2+添入人工饲料中,研究连续3代取食含不同剂量Ni2+饲料的斜纹夜蛾5、6龄幼虫血细胞对凝胶珠包囊反应的影响。将新蜕皮的5龄幼虫记为0 h,每隔24 h注射凝胶珠处理幼虫,直至6龄末,注射24 h后解剖虫体,观察血细胞的包囊情况。结果表明,5 mg/kg及以下处理浓度Ni2+的1代胁迫可提高0-120 h幼虫血细胞对凝胶珠的包囊反应,但2-3代的胁迫只增加发育初期0-72 h幼虫血细胞的包囊反应;10-20 mg/kg处理浓度Ni2+的1代胁迫仅增加0-24 h幼虫血细胞的包囊率,但降低了2-3代幼虫血细胞各发育时间的包囊率。此外,40 mg/kg Ni2+胁迫可连续降低3个世代各个发育阶段幼虫的包囊反应。饲料中Ni2+剂量、胁迫世代数以及两者的交互作用均对幼虫血细胞的包囊率产生了显著影响。

Encapsulation rate of hemocytes of the 5th and 6th instar larvae of Spodoptera litura Fabricius were investigated at 24 h interviews after the larvae were fed on the artificial diets with different doses of nickel for 3 generations. The time of newly moulted 5th instar larvae was labeled as 0 h and the end time of the 6th instar larvae was recorded as 120 h. Results showed It was indicated that one generation＇s nickel exposure with lower levels of nickel （ ≤5 mg/kg） improved the encapsulation response of larvae at the time of 0- 120 h, while two and three generations＇ nickel exposure only increased the encapsulation response of larvae at the time of 0 -72 h. Encapsulation rate of larvae exposed to higher level of nickel （10-20 mg/kg） was only improved after one generation＇s nickel exposure in larvae at 0-24 h. However, long term exposure with higher levels of nickel inhibited immune response of larvae at the all developmental stage. Moreover, 40 mg/kg nickel exposure reduced Encapsulation rate of both 5^th and 6^th instar larvae from all treatments. Results also indicated that nickel doses in diet, exposing generation and nickel doses in diet x exposing generation all have significant effect on the encapsulation of the treated time of the 5^th and 6^th instar larvae.