C-RUI: Tolerance to Damage: Examining Genetic Architecture and Selection of Candidate Traits Using Hybrid Willows

众所周知，一些植物物种比其他物种更能耐受草食动物的破坏，但关于自然选择如何改变耐受性的表达的信息很少。在这个项目中，研究人员使用一个杂交柳树系统来检验对损害的耐受性作为对食草动物的适应性反应所起的作用。研究人员将评估赋予对伤害耐受性的性状，测量F2杂交后代中这些性状的选择梯度，确定通常受选择青睐的性状组合，使用六个遗传类别的柳树来研究耐受性及其性状的遗传结构，并确定植物年龄如何改变耐受性及其机制。为了评估对伤害耐受性的这些方面，从控制杂交繁殖的植物插条将在普通花园中种植，给予50%的枝条伤害或0%的枝条伤害的处理，并评估适合性反应和赋予适合性的性状。通过测量耐性候选性状的选择梯度，研究人员将阐明自然选择在耐害性进化中所起的作用。此外，他们还将评估过去的选择如何影响每个亲本物种的耐受性特征的表达。通过确定如何表达对伤害的耐受性，他们可以评估上位性对耐受性进化的影响，以及两个植物物种之间是否存在加性遗传差异。这些发现将为杂交增强植物对草食动物损害的适应反应的潜力提供洞察。

0108172FritzIt is well know that some plant species tolerate damage by herbivores more than others, but information about how natural selection acts to change the expression of tolerance is scarce. In this project, the investigators use a hybrid willow system to examine the role of tolerance to damage as an adaptive response to browsing herbivores. The researchers will evaluate traits that confer tolerance to damage, measure the selection gradient for those traits in F2 hybrids, determine the sets of trait combinations that are generally favored by selection, use six genetic classes of willows to investigate the genetic architecture of tolerance and its traits, and determine how plant age alters tolerance and its mechanisms. To evaluate these aspects of tolerance to damage, plant cuttings propagated from controlled crosses will be grown in common gardens, given a treatment of either 50% shoot damage or 0% shoot damage, and evaluated for fitness responses and for traits that confer fitness.By measuring the selection gradient for candidate traits of tolerance, the researchers will elucidate the role that natural selection can play in the evolution of tolerance to damage. In addition, they will assess how past selection has shaped the expression of tolerance traits in each parental species. By determining how tolerance to damage is expressed, they can evaluate the influence of epistasis on the evolution of tolerance, as well as the presence or absence of additive genetic variance between the two plant species. These findings will provide insight into the potential for hybridization to enhance the adaptive responses of plants to herbivore damage.