Collaborative Research: Plant Tolerance of Herbivory: A Test for Constraints on Adaptation

合作研究：草食动物的植物耐受性：适应限制的测试

• 批准号: 9815873
• 负责人: Arthur Weis
• 金额: $ 21.09万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9815873&HistoricalAwards=false
• 关键词: Collaborative; Research; Plant; Tolerance; Herbivory

9815873WeisHumans have long been concerned about the impact of insect pests on plant performance. To date ecologists and agronomists have concentrated on plant resistance to attack, that is, the plant's ability to deter potential enemies. However, insect attack is rarely fatal and so plants have the opportunity for a second way to deal with enemy attack, to recover and regrow. The ability to survive and prosper after attack is called tolerance. Compared to the research progress in understanding the genetics and ecology of resistance, very little is known about plant recovery. This knowledge void hampers understanding of the total plant defense system. Not only is it important to study the cost-benefit structure of tolerance in it own right, we also need to understand tolerance to understand the adaptive value of resistance. The interdependence of resistance and tolerance emerges from two considerations. First, resistance and tolerance can be redundant-if a plant can completely recover from attack, there is little profit in also resisting attack. The second consideration arises from optimal defense theory. It is widely hypothesized that resistance factors are costly since resources devoted to resistance cannot also be allocated to growth. Numerous experiments have tested this hypothesis, but with mixed results. Recent models suggest that resistance costs are hard to detect because they are obscured by tolerance costs. But because little is known about tolerance, little is known about tolerance costs. Thus, there is little basis for evaluating these important theoretical predictions. These experiments will look for tolerance costs using a wild mustard species, Brassica campestris, which is the wild progenitor of canola, the important oil seed crop. Artificial selection will be perform to determine if genetic trade-offs impose a fitness cost that constrains the ability of B. campestris to tolerate defoliation. This experiment involves selecting for performance in plant lines that experience sever damage every generation, lines that never experience damage, and lines that experience both. Selection will be by sib-selection. Following several generations of selection, tolerance differences among the lines will be measured by growing them across all damage environments. These experiments, thus, will test several major hypotheses about genetic constraints on tolerance, and will initiate a long-term effort to identify the physiological traits, and the underlying genetic loci, that contribute to plant recovery. In addition, by examining selection response across two environments, these experiments will offer insights on the more general problem of constraints on selection for phenotypic plasticity.H:\popbio\abstracts\fy1999\9815873 (Weis abstract)

9815873Weis人类长期以来一直关注害虫对植物性能的影响。 迄今为止，生态学家和农学家主要关注植物对攻击的抵抗力，即植物阻止潜在敌人的能力。 然而，昆虫的攻击很少是致命的，因此植物有机会采用第二种方式来应对敌人的攻击，即恢复和再生。 遭受攻击后生存并繁荣的能力称为忍耐。 与了解抗性遗传学和生态学的研究进展相比，人们对植物恢复知之甚少。 这种知识空白阻碍了对整个植物防御系统的理解。 不仅研究容忍本身的成本效益结构很重要，我们还需要了解容忍以了解抵抗的适应性价值。 抵抗和宽容的相互依存源于两个考虑。 首先，抵抗和容忍可能是多余的——如果植物可以完全从攻击中恢复，那么抵抗攻击也没有什么好处。 第二个考虑来自最优防御理论。 人们普遍认为，阻力因素的成本很高，因为用于阻力的资源不能同时分配给增长。 许多实验都检验了这一假设，但结果好坏参半。 最近的模型表明，抵抗成本很难检测，因为它们被容忍成本掩盖了。 但由于人们对宽容知之甚少，因此对宽容的成本也知之甚少。 因此，评估这些重要的理论预测几乎没有依据。 这些实验将使用野生芥菜品种甘蓝（Brassica Campestris）来寻找耐受成本，它是重要的油料作物双低油菜籽的野生祖先。将进行人工选择，以确定遗传权衡是否会带来适应性成本，从而限制 B.campestris 耐受落叶的能力。 该实验涉及选择每一代都经历严重损害的植物品系、从未经历过损害的品系以及经历两者的品系的性能。 选拔将通过同胞选拔进行。 经过几代选择后，将通过在所有损坏环境中生长它们来测量品系之间的耐受性差异。 因此，这些实验将测试关于耐受性遗传限制的几个主要假设，并将启动一项长期努力，以确定有助于植物恢复的生理特征和潜在遗传位点。 此外，通过检查两种环境中的选择反应，这些实验将为表型可塑性选择的约束这一更普遍的问题提供见解。H:\popbio\abstracts\fy1999\9815873（Weis 摘要）