在未来变暖的情况下,干旱可能成为谷物生产面临的最大挑战之一。其对虫害爆发的影响仍然存在争议。为了解决这个问题,英国谷物蚜虫的生活史反应,Sitobionavenae(Fabricius),从三个不同干旱水平的地区,在三种水处理下进行了比较。
在发育时间上发现了显著差异,来自潮湿的S.avenae克隆的繁殖力和成年体重,在所有三种水处理下的半干旱和干旱地区。半干旱和干旱地区的克隆比潮湿地区的克隆具有更高的测试生活史性状遗传力。我们确定了半干旱和干旱地区克隆在1龄若虫的发育时间和成年体重上的重要水分亏缺选择。中度和重度水分胁迫对S.avenae's适应性的影响是中性和负面的(例如,繁殖力和体重降低),分别。与干旱地区克隆相比,潮湿和半干旱地区的克隆对各自来源环境的水分亏缺水平的适应程度更高。在不同的水分胁迫条件下,成年体重被确定为S.avenae适应潜力的良好指标。在他们只经历了五代人的中等缺水压力之后,潮湿和半干旱地区克隆的成年体重和繁殖力趋于下降,但干旱地区克隆的增加。
从我们的研究中可以明显看出,S.avenae克隆来自潮湿,半干旱和干旱地区在不同的水分亏缺胁迫下分化,这种差异可能有遗传基础。干旱对马尾草适应度的影响呈水位依赖模式。与严重的水分亏缺胁迫相比,阿文的克隆更有可能适应中度水分亏缺胁迫。在仅仅五代人的持续缺水胁迫之后,对于潮湿和半干旱地区的克隆,马尾草的适应潜力趋于下降,但增加干旱地区的克隆。在未来的气候变化情景中,蚜虫的生活史特征和适应潜力的快速变化可能对它们的进化动态和爆发风险产生重大影响。
Drought may become one of the greatest challenges for cereal production under future warming scenarios, and its impact on insect pest outbreaks is still controversial. To address this issue, life-history responses of the English grain aphid, Sitobion avenae (Fabricius), from three areas of different drought levels were compared under three water treatments.
Significant differences were identified in developmental time, fecundity and adult weight among S. avenae clones from moist, semiarid and arid areas under all the three water treatments. Semiarid and arid area clones tended to have higher heritability for test life-history traits than moist area clones. We identified significant selection of water-deficit on the developmental time of 1st instar nymphs and adult weight for both semiarid and arid area clones. The impact of intermediate and severe water-stress on S. avenae\'s fitness was neutral and negative (e.g., decreased fecundity and weight), respectively. Compared with arid-area clones, moist- and semiarid-area clones showed higher extents of adaptation to the water-deficit level of their respective source environment. Adult weight was identified as a good indicator for S. avenae\'s adaptation potential under different water-stress conditions. After their exposure to intermediate water-deficit stress for only five generations, adult weight and fecundity tended to decrease for moist- and semiarid-area clones, but increase for arid-area clones.
It is evident from our study that S. avenae clones from moist, semiarid and arid areas have diverged under different water-deficit stress, and such divergence could have a genetic basis. The impact of drought on S. avenae\'s fitness showed a water-level dependent pattern. Clones of S. avenae were more likely to become adapted to intermediate water-deficit stress than severe water-deficit stress. After continuous water-deficit stress of only five generations, the adaptation potential of S. avenae tended to decrease for moist and semiarid area clones, but increase for arid area clones. The rapid shift of aphids\' life-history traits and adaptation potential under drought could have significant implications for their evolutionary dynamics and outbreak risks in future climate change scenarios.