Abstract:
Although different ecological factors shape adaptative evolution in natural habitats, we know little about how their interactions impact local adaptation. Here we used eight generations of experimental evolution with outcrossing Brassica rapa plants as a model system, in eight treatment groups that varied in soil type, herbivory (with/without aphids), and pollination mode (hand- or bumblebee-pollination), to study how biotic interactions affect local adaptation to soil. First, we show that several plant traits evolved in response to biotic interactions in a soil-specific way. Second, using a reciprocal transplant experiment, we demonstrate that significant local adaptation to soil-type evolved in the \"number of open flowers\", a trait used as a fitness proxy, but only in plants that evolved with herbivory and bee pollination. Whole genome re-sequencing of experimental lines revealed that biotic interactions caused a 10-fold increase in the number of SNPs across the genome with significant allele frequency change, and that alleles with opposite allele frequency change in different soil types (antagonistic pleiotropy) were most common in plants with an evolutionary history of herbivory and bee pollination. Our results demonstrate that the interaction with mutualists and antagonists can facilitate local adaptation to soil type through antagonistic pleiotropy.
摘要:
尽管不同的生态因素塑造了自然栖息地的适应性进化,我们对它们的相互作用如何影响本地适应知之甚少。在这里,我们使用八代实验进化与异型芸苔属植物作为模型系统,在八个不同土壤类型的处理组中,食草动物(有/没有蚜虫),和授粉模式(人工或大黄蜂授粉),研究生物相互作用如何影响当地对土壤的适应。首先,我们表明,几种植物性状以土壤特异性方式响应生物相互作用而进化。第二,使用互惠移植实验,我们证明了对土壤类型的显著局部适应在“开放花的数量”中进化,用作健身代理的特征,但仅限于通过食草和蜜蜂授粉进化的植物。实验系的全基因组重新测序表明,生物相互作用导致整个基因组中SNP数量增加10倍,等位基因频率显著变化,在具有食草和蜜蜂授粉进化史的植物中,在不同土壤类型(拮抗多效性)中具有相反等位基因频率变化的等位基因最常见。我们的结果表明,与相互主义者和拮抗剂的相互作用可以通过拮抗多效性促进局部适应土壤类型。