LC30与LC50棘孢木霉发酵液对亚洲玉米螟种群的致死效应分析

Lethal effects of LC30 and LC50 fermentation broths of Trichoderma asperellum on population of the Asian corn borer Ostrinia furnacalis

中文关键词:棘孢木霉  发酵液  亚洲玉米螟  两性生命表  种群合适度

keywords:Trichoderma asperellum  fermentation broth  Ostrinia furnacalis  two-sex life table  population fitness

中文摘要:为评估棘孢木霉Trichoderma asperellum GDFS1009发酵液对亚洲玉米螟Ostrinia furnacalis的毒力和致死效应，利用概率值分析法分析其对亚洲玉米螟1龄幼虫的LC₃₀与LC₅₀，并通过年龄-阶段两性生命表解析LC₃₀与LC₅₀发酵液胁迫下亚洲玉米螟发育历期、繁殖参数和种群参数的变化。结果表明：棘孢木霉发酵液对亚洲玉米螟1龄幼虫的LC₃₀和LC₅₀分别为3.58×10⁴个/mL和7.78×10⁴个/mL。LC₃₀和LC₅₀棘孢木霉发酵液均会延长亚洲玉米螟幼虫发育历期、蛹期和成虫前期，均能缩短成虫产卵前期、总产卵前期和成虫寿命；同时，LC₃₀和LC₅₀棘孢木霉发酵液处理下亚洲玉米螟蛹重均显著降低，且单雌产卵量较对照分别显著降低了31.31%和71.14%。LC₅₀棘孢木霉发酵液处理极显著降低了亚洲玉米螟的净增殖率、内禀增长率、周限增长率，较对照分别下降了80.00%、9.10%和5.30%，而平均世代周期从32.90 d显著延长至35.76 d;LC₃₀棘孢木霉发酵液处理下以上种群参数与对照组相比均无显著变化。表明LC₃₀与LC₅₀棘孢木霉发酵液通过延长亚洲玉米螟发育周期与抑制繁殖力的协同作用阻碍其种群增长，具有开发为木霉制剂的潜力。

Abstract:To evaluate the virulence and lethal effects of the fermentation broth of Trichoderma asperellum GDFS1009 against the Asian corn borer Ostrinia furnacalis, the LC₃₀and LC₅₀values against firstinstar larvae were determined using probit analysis. Subsequently. An age-stage, two-sex life table was then employed to analyze changes in developmental duration, reproductive parameters, and population parameters of O. furnacalis under LC₃₀and LC₅₀fermentation broth treatments. The results demonstrated that the LC₃₀and LC₅₀values of T. asperellum fermentation broth against first-instar larvae of O. furnacalis were 3.58×10⁴and 7.78×10⁴spores/mL, respectively. Both LC₃₀and LC₅₀treatments prolonged larval development duration, pupal duration and the pre-adult period, while shortening the adult preoviposition period, total preoviposition period, and adult longevity. In addition, pupal weight was significantly decreased under both treatments, and fecundity per female was significantly reduced by 31.31% and 71.14%, respectively. Furthermore, the LC₅₀treatment significantly decreased the net reproductive rate(R₀), intrinsic rate of increase(r), and finite rate of increase(λ) of O. furnacalis by 80.00%, 9.10%, and 5.30%, respectively, and significantly prolonged the mean generation time(T) from 32.90 d to 35.76 d. In contrast, these population parameters did not differ significantly between the LC₃₀treatment and the control. These findings indicate that LC₃₀and LC₅₀fermentation broths of T. asperellum hinder the population growth of O. furnacalis through the combined effects of prolonging developmental duration and suppressing fecundity, demonstrating potential for development as Trichoderma-based biocontrol agents.