Climate effects on life cycle variation and population genetic architecture of the black bean aphid, Aphis fabae

Aphid species commonly have different reproductive modes ranging from cyclical to obligate parthenogenesis. The distribution of life cycle variation in aphids is generally determined by ecological forces, mainly climate, because only sexually produced diapausing eggs can survive harsh winters. Aphids are thus interesting models to investigate intrinsic and environmental factors shaping the competition among sexual and asexual lineages. We conducted a Europe-wide sampling of black bean aphids, Aphis fabae, and combined population genetic analyses based on microsatellite data with an experimental determination of life cycle strategies. Aphids were collected from broad beans (Vicia faba) as well as some Chenopodiaceae, but we detected no genetic differentiation between aphids from different host plants. Consistent with model predictions, life cycle variation was related to climate, with aphids from areas with cold winters investing more in sexual reproduction than aphids from areas with mi...

蚜虫物种通常具有多样的生殖模式，范围涵盖从周期性孤雌生殖 (cyclical parthenogenesis) 至专性孤雌生殖 (obligate parthenogenesis)。蚜虫生活史变异的地理分布格局通常由生态因子主导，其中气候因素最为关键——这是因为唯有经有性生殖产生的滞育卵 (diapausing eggs)，方可在严酷的冬季存活。因此，蚜虫是探究调控有性与无性谱系间竞争的内在与环境因子的理想研究模型。本研究针对欧洲全域开展蚕豆蚜 (Aphis fabae) 进行采样，并将基于微卫星数据 (microsatellite data) 的群体遗传学分析与生活史策略的实验测定相结合。研究采集的蚜虫宿主涵盖蚕豆 (Vicia faba) 以及部分藜科 (Chenopodiaceae) 植物，但未检测到不同宿主来源的蚜虫间存在遗传分化。与模型预测结果一致，蚜虫的生活史变异与气候密切相关：冬季寒冷区域的蚜虫，相较于冬季温和区域的蚜虫，会投入更多资源开展有性生殖。