Evolution of plant resistance and tolerance to frost damage
Evolution of plant resistance and tolerance to frost damage
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DOI：
10.1111/j.1461-0248.2004.00680.x
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发表时间：
2004-12-01
期刊：
影响因子：
8.8
通讯作者：
Stinchcombe, JR
中科院分区：
文献类型：
--
作者：
Agrawal, AA;Conner, JK;Stinchcombe, JR
植物对任何类型的胁迫的防御可能涉及抗性（减少损害的性状）或耐受性（减少损害的负面适应性影响的性状）。这两种策略被认为是多余的进化选择。季末霜冻使我们能够估计自然选择和遗传限制对野生植物物种抗冻性和耐霜冻性进化的影响。我们采用了遗传选择分析（这是无偏的性状和健身之间的环境相关性）的75个父系半同胞家庭的一年生野生萝卜[萝卜（萝卜科）]。在安大略南部的一个实验种群中，我们发现强选择有利于植物抗霜冻，但选择对耐霜冻。对耐受性的选择可能是由耐受性的成本引起的，因为我们提供了证据，在没有霜冻损害的情况下，耐受性和适应性之间存在负遗传相关。虽然我们没有发现任何证据的理论预测之间的权衡抗冻性和电阻在我们的家庭，我们确实检测到负相关选择作用于这两个性状，表明自然选择有利于高抗结合低容忍度和低电阻加上高容忍度，但不是高或低水平的两个性状在一起。总体上，所测性状之间的遗传相关性很小，但耐霜冻性与初始种子质量呈负相关，耐霜冻性与抗昆虫植食性呈正相关。周期性的强选择事件，如由季节末的霜冻引起的，可能在进化中不成比例地重要，并且可能因为人类对环境的改变而变得更加普遍。
Plant defence against any type of stress may involve resistance (traits that reduce damage) or tolerance (traits that reduce the negative fitness impacts of damage). These two strategies have been proposed as redundant evolutionary alternatives. A late-season frost enabled us to estimate natural selection and genetic constraints on the evolution of frost resistance and tolerance in a wild plant species. We employed a genetic selection analysis (which is unbiased by environmental correlations between traits and fitness) on 75 paternal half-sibling families of annual wild radish [Raphanus raphanistrum (Brassicaceae)]. In an experimental population in southern Ontario, we found strong selection favouring plant resistance to frost, but selection against tolerance to frost. The selection against tolerance may have been caused by a cost of tolerance, as we provide evidence for a negative genetic correlation between tolerance and fitness in the absence of frost damage. Although we found no evidence for the theoretically predicted trade-off between frost tolerance and resistance among our families, we did detect negative correlational selection acting on the two traits, indicating that natural selection favoured high resistance combined with low tolerance and low resistance coupled with high tolerance, but not high or low levels of both traits together. There were few genetic correlations between the measured traits overall, but frost tolerance was negatively correlated with initial seed mass, and frost resistance was positively correlated with resistance to insect herbivory. Periodic episodes of strong selection such as that caused by the late-season frost may be disproportionately important in evolution, and are likely becoming more common because of human alterations of the environment.