意大利蜜蜂工蜂幼虫饲粮的适宜亚硒酸钠添加水平

【目的】探索意大利蜜蜂(Apis mellifera ligustica)工蜂幼虫日粮的适宜亚硒酸钠水平,为意大利蜜蜂工蜂幼虫发育阶段硒的营养需要提供依据。【方法】共取1 440只1日龄意大利蜜蜂工蜂幼虫并平均分为两批,每批720只,一批用于化蛹率、羽化率的测定,一批用于理化指标和分子指标的测定。两批幼虫均按单因素完全随机设计分成6组,对照组饲喂基础日粮,试验组分别饲喂亚硒酸钠添加量为0.2、0.4、0.6、0.8、1.0 mg·kg~(-1)的日粮,每组5个重复,每个重复24只幼虫。取3、5、7日龄幼虫测定体重、总抗氧化能力(total antioxidant capacity,T-AOC)、总超氧化物歧化酶(total superoxide dismutase,T-SOD)活性、丙二醛(malondialdehyde,MDA)含量、酚氧化酶(phenoloxidase,PO)活性,取5日龄幼虫测定硒磷酸合成酶(selenide water dikinase,Sel D)、丝氨酰-t RNA合成酶(seryl-t RNA synthetase,Ser Rs)、SECIS-结合蛋白1(SECIS-binding protein 1,Sbp1)、SECIS-结合蛋白2(SECIS-binding protein 2,Sbp2)基因表达量;7日龄时统计化蛹率。【结果】与对照组相比,日粮添加亚硒酸钠水平为0.2—0.6 mg·kg~(-1)时显著提高了幼虫的T-AOC(P0.05),日粮添加亚硒酸钠水平为0.2—0.8 mg·kg~(-1)时显著提高了幼虫的T-SOD活性(P0.05),各试验组均显著降低了幼虫的MDA含量(P0.05)。日粮添加亚硒酸钠水平为0.4 mg·kg~(-1)时幼虫的PO活性显著高于对照(P0.05)。日粮添加亚硒酸钠水平为0.6 mg·kg~(-1)时5日龄幼虫的Sel D、Ser Rs、Sbp1、Sbp2基因表达水平显著高于对照(P0.05)。日粮添加亚硒酸钠水平为0.4 mg·kg~(-1)时幼虫化蛹前体重显著高于对照(P0.05)。与对照组相比,日粮添加亚硒酸钠水平为0.2 mg·kg~(-1)时,幼虫化蛹率显著提高(P0.05)。【结论】人工饲养条件下基础日粮硒水平为0.21 mg·kg~(-1)时,根据幼虫化蛹前体重、化蛹率做拟合曲线得出意大利蜜蜂工蜂幼虫日粮适宜亚硒酸钠添加水平为0.24—0.33 mg·kg~(-1),即意大利蜜蜂工蜂幼虫的适宜硒水平为0.32—0.36 mg·kg~(-1)。

Appropriate Level of Sodium Selenite for Apis mellifera ligustica Worker Bee Larvae Feed

【objective】The objective of this study is to find an appropriate level of sodium selenite which added in the food of Apis mellifera ligustica worker larvae, and to provide a theoretical basis for the nutritional needs of Se.【Method】A total of 1 440 one-day old larvae were randomly allotted into 2 batches, each batch involve 720 larvae, one of the batch was used to measure the pupation rate and eclosion rate, the other was used to measure enzyme activity and molecular index. Two batches were all randomly divided into 6 groups, the control group was fed basic diet and the treatment groups were fed different diets with sodium selenite at the levels of 0.2, 0.4, 0.6, 0.8, and 1.0 mg·kg^-1, respectively. Each group had 5 repetitions and involved 24 larvae in each. The 3-, 5- and 7-day-old larvae were used to measure larvae weight, T-AOC (total antioxidant capacity), T-SOD (total superoxide dismutase), MDA (malondialdehyde), and PO (phenoloxidase). The gene expression of SelD, SerRs, Sbp1 and Sbp2 were measured by using 5-day-old larvae. The pupation rate was calculated at 7-day-old.【Result】Compared with the control group, when the added levels of sodium selenite were 0.2-0.6 mg·kg^-1, the T-AOC was significantly increased (P＜0.05), when the added levels of sodium selenite were 0.2-0.8 mg·kg^-1, the activity of T-SOD was significantly increased (P＜0.05) and the MDA content of all the treatment groups was significantly decreased (P＜0.05). When the added level of sodium selenite was 0.4 mg·kg^-1, the activity of PO was significantly increased (P＜0.05). When the added level of sodium selenite was 0.6 mg·kg^-1, the gene expression levels of SelD, SerRs, Sbp1and Sbp2 was significantly higher than the control in 5-day-old larvae (P＜0.05). When the added level of sodium selenite was 0.4 mg·kg^-1, the weight before pupation was significantly higher than the control (P＜0.05). Compared with the control group, when the added level of sodium selenite was 0.2 mg·kg^-1, the pupation rate were significantly increased (P＜0.05). 【Conclusion】Under artificial condition, when the selenium level of basic diet was 0.21 mg·kg^-1, the appropriate level of sodium selenite which added in the food of A. m. ligusticaby the fitting curve which involve the weight before pupation and the pupation rate, and it means that the appropriate level of selenium which added in the food of A. m. ligustica worker larvae is 0.32-0.36 mg·kg^-1. worker larvae was 0.24-0.33 mg·kg^-1