Cao Jun-Yu, Xing Kun, Liu Hui-Ping, Zhao Fei
College of Agriculture, Shanxi Agricultural University, Taigu 030801, China; Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Institute of Plant Protection, Shanxi Academy of Agricultural Sciences, Taiyuan 030031, China.
Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Institute of Plant Protection, Shanxi Academy of Agricultural Sciences, Taiyuan 030031, China.
J Therm Biol. 2018 Dec;78:58-64. doi: 10.1016/j.jtherbio.2018.09.004. Epub 2018 Sep 11.
Most ectotherms are able to increase their tolerance to heat stress via the acclimation response. However, there is ongoing debate about whether the acclimation response is associated with fitness costs, and what factors can affect the consequences of acclimation are still unclear. To elucidate this, we sought to determine whether fitness costs varied with acclimation conditions in two cereal aphids, Sitobion avenae and Rhopalosiphum padi. Thus, the basal and inducible thermal tolerances (maximum critical temperature [CT]) and fitness traits (proportion of adult emergence, adult longevity, fecundity, and population parameters) of adult aphids were measured under three conditions of developmental acclimation: 1) 22 °C constant temperature (no acclimation), 2) 22 °C + 34 °C for 2 h per day (low daytime temperature), and 3) 22 °C + 38 °C for 2 h per day (high daytime temperature). We found that the thermal tolerances of both species were significantly higher following developmental acclimations, where higher basal and inducible thermal tolerances were observed in R. padi than in S. avenae. Low daytime temperature acclimation conditions (34 °C) resulted in negligible reproductive costs and improved the intrinsic rates of population increase in both species. In contrast, substantial fitness costs were detected in both species in response to high daytime temperature acclimation (38 °C), especially for S. avenae. Our results indicate that the effects of acclimation conditions on fitness costs differ between the two aphid species. These findings will not only enhance our understanding of species dynamics in the context of climate change but could also potentially improve pest control efforts.
大多数变温动物能够通过驯化反应提高对热应激的耐受性。然而，关于驯化反应是否与适应性代价相关，以及哪些因素会影响驯化的后果，目前仍存在争议。为了阐明这一点，我们试图确定在两种谷物蚜虫，即麦长管蚜和禾谷缢管蚜中，适应性代价是否随驯化条件而变化。因此，在三种发育驯化条件下测量了成年蚜虫的基础和诱导热耐受性（最高临界温度[CT]）以及适应性特征（成虫羽化比例、成虫寿命、繁殖力和种群参数）：1）22°C恒温（无驯化），2）每天22°C + 34°C处理2小时（低日间温度），3）每天22°C + 38°C处理2小时（高日间温度）。我们发现，经过发育驯化后，两种蚜虫的热耐受性均显著提高，其中禾谷缢管蚜的基础和诱导热耐受性高于麦长管蚜。低日间温度驯化条件（34°C）导致的繁殖代价可忽略不计，并提高了两种蚜虫的种群内禀增长率。相比之下，在高日间温度驯化（38°C）条件下，两种蚜虫均检测到显著的适应性代价，尤其是麦长管蚜。我们的结果表明，驯化条件对适应性代价的影响在两种蚜虫之间存在差异。这些发现不仅将增进我们在气候变化背景下对物种动态的理解，还可能改善害虫防治工作。
