Evolutionary changes in plant tolerance against herbivory through a resurrection experiment
Evolutionary changes in plant tolerance against herbivory through a resurrection experiment
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DOI：
10.1111/jeb.12307
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发表时间：
2014-03-01
影响因子：
2.1
通讯作者：
Nunez-Farfan, J.
中科院分区：
文献类型：
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作者：
Bustos-Segura, C.;Fornoni, J.;Nunez-Farfan, J.
理论和实证研究都强调了宿主对敌人的抗性和耐受性在进化意义上的差异。然而，很难在自然种群中显示宿主防御的进化变化；因此，评估防御同时进化的理论预测仍然是一个挑战。利用20年采集的两个天然植物种群的种子，研究了天然植物种群对草食抗性和耐受性相关性状的进化变化。在一个普通的园林实验中，我们比较了一年生植物曼陀罗祖先（1987年）和后代（2007年）亚群的防御性状，这些性状显示出耐受性的遗传变异，并且专科食草动物曼陀罗在当地适应了这种变异。我们还研究了不同植物基因型对草食动物抗性的影响，以测试植物的遗传变异。基于对当代食草动物种群的响应，结果表明，植物抗性性状（食草动物消耗量、叶面毛状和tropane生物碱）的响应不显著，但耐受性的响应显著。在实验室实验中，食草动物的生存依赖于植物的基因型，这表明植物的抗性存在遗传变异。虽然我们不能确定这种变化的选择因子，也不能排除遗传漂变，但结果与预期一致，即当抗性不能控制食草性时，耐受性应该在相互作用的进化中发挥更重要的作用。
Both theoretical and empirical works have highlighted the difference in the evolutionary implications of host resistance and tolerance against their enemies. However, it has been difficult to show evolutionary changes in host defences in natural populations; thus, evaluating theoretical predictions of simultaneous evolution of defences remains a challenge. We studied the evolutionary changes in traits related to resistance and tolerance against herbivory in a natural plant population using seeds from two collections made in a period of 20 years. In a common garden experiment, we compared defensive traits of ancestral (1987) and descendant (2007) subpopulations of the annual plantDatura stramoniumthat shows genetic variation for tolerance and to which the specialist herbivoreLema daturaphilais locally adapted. We also examined the effects of different plant genotypes on the herbivore for testing the plant genetic variation in resistance. Based on the response to the contemporary herbivore populations, results revealed a nonsignificant response in plant resistance traits (herbivore consumption, foliar trichomes and tropane alkaloids), but a significant one in tolerance. The survival of herbivores in laboratory experiments depended on the plant genotype, which suggests genetic variation in plant resistance. Although we cannot identify the selective agent for the change nor exclude genetic drift, the results are consistent with the expectation that when resistance fails to control herbivory, tolerance should play a more important role in the evolution of the interaction.