Collaborative Research: The Evolution of Tolerance to Herbivory among Populations of Scarlet Gilia, Ipomopsis aggregata

植物对草食的反应可分为两部分：植物防御和植物耐受。耐受性是指植物在食草动物伤害后再生和繁殖的能力；也就是补偿的能力。然而，人们对耐受性是如何进化的知之甚少，迄今为止大多数研究都集中在植物防御上。在过去的15年里，人们对一种二年生/多年生草本植物红茉莉的耐受性进行了专门研究，在这种植物中，人们观察到植物通过过度补偿因食草而失去的组织来获得更大的繁殖成功率。然而，红蝇的代偿反应并不普遍；在种群内部和种群之间表现出巨大的变异。为了评估群体补偿差异是否存在遗传基础，以及与补偿相关的植物性状的选择是否在群体和地点之间存在差异，将进行相互移植实验和选择分析。这些研究将在四个不同历史食草水平的种群中进行；其中两个过度补偿，另外两个则没有。研究遗传因素与环境因素的相对重要性以及不同环境下的选择，有助于我们理解植物对食草性的进化反应，并对食草性后繁殖成功率提高的因素有更全面的认识。如果过度补偿的机制是基于遗传的，那么这种对草食的反应应该引起农业学家的极大兴趣，他们通过分子遗传技术的最新进展，可能会将这些特征纳入作物植物中。

0108354ConnerPlant responses to herbivory can be divided into two components, plant defenses and tolerance. Tolerance refers to the ability of plants to regrow and reproduce following herbivore damage; i.e., the ability to compensate. Yet little is known about how tolerance evolves, with most studies to date focusing on plant defense. Over the past fifteen years studies have been conducted on a specialized case of tolerance in a biennial/perennial herb, scarlet gilia, where plants have been observed to achieve greater reproductive success by overcompensating for tissues lost to herbivory. However, scarlet gilia's compensatory response is not universal; exhibiting tremendous variation both within and between populations. To assess whether there is a genetic basis to population differences in compensation, as well as whether selection on plant traits related to compensation differ between populations and locations, reciprocal transplant experiments and selection analyses will be conducted. These studies will be conducted within each of four populations that have been subjected to very different historical levels of herbivory; two of these overcompensate and the other two do not.Studies on the relative importance of genetic versus environmental factors and selection in different environments should contribute to our understanding of the evolutionary response of plants to herbivory, and add general understanding to the factors that do and do not lead to enhanced reproductive success following herbivory. If the mechanisms of overcompensation are genetically based, such responses to herbivory should be of great interest to agriculturists who, through recent advents in molecular genetic technique, might incorporate these traits into crop plants.