UV-B与重金属Cd双重胁迫对麦长管蚜种群生长发育和繁殖的影响

【目的】为探究UV-B和重金属Cd双重胁迫对麦长管蚜 Sitobion avenae (Fabricius)生长发育和繁殖的影响，以及UV-B和重金属Cd两因素间的交互作用。【方法】在室内，不同辐射强度UV-B（0, 0.1, 0.2和0.7 mW/cm²）与不同浓度重金属Cd (0, 20, 40, 80 和160 mg/kg）处理后，采用特定年龄生命表方法，统计麦长管蚜种群参数、繁殖参数、存活率和繁殖力的变化。【结果】麦长管蚜种群的生命表各参数受UV-B与重金属Cd双重胁迫影响显著，且UV-B对麦长管蚜的生命表各参数影响要大于重金属Cd；UV-B和重金属Cd两因素间存在交互作用。同一重金属Cd浓度时，随着UV-B辐射强度的增加，麦长管蚜种群的内禀增长率r、周限增长率λ、净增殖率 R₀ 、繁殖力 F、产仔天数和成虫寿命均呈现先下降后上升的趋势，且均在UV-B辐射强度为0.2 mW/cm²时下降至最低点；而麦长管蚜种群的平均世代周期T则呈现先升高后下降的趋势，且在UV-B辐射强度为0.1 mW/cm²时上升至最高点。同一UV-B辐射强度下，随着重金属Cd浓度的增加，麦长管蚜种群生命表各参数均呈现波动变化；双重胁迫处理组麦长管蚜种群内禀增长率 r、周限增长率 λ、净增殖率R₀ 、繁殖力F、产仔天数和成虫寿命均显著低于单一重金属Cd处理组，而其平均世代周期 T 显著高于单一重金属Cd处理组，且双重胁迫处理组生命表各参数的峰值点较单一因素重金属Cd处理组均呈现不同程度的提前。【结论】UV-B与重金属Cd影响麦长管蚜种群的生长发育和繁殖，且由于这两因素间存在交互作用，二者双重胁迫对麦长管蚜种群的生长发育和繁殖影响更加严重。

Effects of the dual stress of UV-B and cadmium on the growth,development and fecundity of Sitobion avenae (Hemiptera: Aphididae)

【Aim】 To explore the effects of the dual stress of UV-B and cadmium on the growth, development and fecundity of Sitobion avenae (Fabricius), and to determine whether there is the interaction between UV-B and cadmium. 【Methods】 The age-specific life table was employed to explore the effects of the co-stress of different intensities of UV-B (0, 0.1, 0.2 and 0.7 mW/cm²) and concentrations of cadmium (0, 20, 40, 80 and 160 mg/kg) on the growth, development and fecundity of S. avenae in the laboratory. 【Results】 The life table parameters of S. avenae were adversely influenced by the dual stress of UV-B and cadmium, and they were affected more severely by UV-B than by cadmium stress. In addition, there are significant interactions between the stress of UV-B and cadmium. In particular,under the same concentration of cadmium treatments, the effects of UV-B on the intrinsic rate of increase (r), the finite rate of increase (λ), the net rate of increase (R₀), fecundity (F), oviposition duration and adult longevity of S. avenae showed a trend of first decreasing and then increasing, and fell to the minimum value under the intensity of 0.2 mW/cm² of UV-B. However, the mean length of a generation (T) revealed an adverse trend, namely showing a trend of first increasing and then decreasing, and reached the first peak at the intensity of 0.1 mW/cm² of UV-B. Under the same intensity of UV-B radiation, with the increase of the concentrations of cadmium, all life table parameters of S. avenae displayed fluctuation. Moreover, the parameters of r, λ, R₀, F, oviposition duration and adult longevity of S. avenae in the combined treatments were significantly lower than those in the treatments only exposed to different concentrations of cadmium. However, the parameter T revealed a reverse result. Every peak point or minimum value of all above life table parameters of S. avenae exposed to the dual stress of UV-B and cadmium was somewhat earlier than that only exposed to different concentrations of cadmium. 【Conclusion】 The growth, development and fecundity of S. avenae were significantly affected by the stress of UV-B and cadmium. Moreover, the influences will be intensified when the two factors act in combination, suggesting that these two factors have significant interactions.