Insecticidal activities and effects on three enzymic activities caused by 5-aminolevulinic acid （ALA） on Oxya chinensis were studied. Fourth-instar nymphs of O. chinensis were treated with different doses ofALA （A1,250 mM; A2, 450 mM; A3,750 mM; A4, 1 000 mM）. Mortality and the activities of acetylcholinesterase （ACHE）, glutathione S-transferase （GSTs）, and glutathione peroxidase （GPx） were determinated. The mortality of O. chinensis rose with an increasing dose of ALA. The mortality of high-dose treatments A3 and A4 reached 66.19 and 80.21%, respectively. The value of LD50 was 3.61 （3.29-3.93） mg·g^-1 body weight （95% confidence interval）. Biochemical studies showed that the activities of AChE and GPx in the A4 treatment declined by 51.53 and 42.82% in the female, and 42.65 and 43.85% in the male compared to the control, respectively, and the degree of decline reached a significant level at P 〈 0.05. Meanwhile, the GSTs activities of O. chinensis enhanced with increasing dose of ALA. The GSTs activities of female and male O. chinensis in the A4 treatment remarkably increased by 171.05 and 97.42% compared to the control （P〈 0.05）. ALA had an obviously toxic effect on O. chinensis. Moreover, ALA caused the photoinactivation of AChE and GPx, which induced nerve transmission blocking and the capability to defend oxidation damage declining. Meanwhile, a high dose of ALA could activate GSTs, which caused a feedback inhibition of the insect to the phototoxic substance.
YIN Kun MA En-bo XUE Chun-rong WU Hai-hua GUO Ya-ping ZHANG Jian-zhen
采用Bead beating法和QIAamp DNA stool mini kit法提取蝗虫肠道微生物总DNA,并对2种方法提取DNA的得率、完整性以及16SrRNA基因扩增产物的变性梯度凝胶电泳(denaturing gradient gel electrophoresis,DGGE)图谱等进行综合比较。结果表明,Bead beating法提取DNA的得率显著高于QIAamp DNA stool mini kit法(P=0.042),而QIAamp DNA stool mini kit法提取DNA片段更完整。PCR-DGGE检测微生物多样性结果显示,QIAamp DNA stool mini kit法提取DNA所代表的微生物群落多样性略高于Bead beating法,但Mann-Whitley统计学检验表明用2种方法检测蝗虫肠道微生物多样性无显著差异(P=0.17)。因此在蝗虫肠道微生物群落多样性的检测中QIAamp DNA stool mini kit法具一定的优势,而Bead beating法同样适用。
