Effects of Stress and Phenotypic Variation on Inbreeding Depression in Brassica rapa
Effects of Stress and Phenotypic Variation on Inbreeding Depression in Brassica rapa
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胁迫和表型变异对白菜近交衰退的影响
DOI：
10.1111/j.1558-5646.2008.00325.x
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发表时间：
2008
影响因子：
3
通讯作者：
A. Bersch
中科院分区：
文献类型：
--
作者：
D. Waller;J. Dole;A. Bersch
摘要压力环境通常被认为会增加近交衰退的表达。或者，克劳的“选择机会”（表型变异系数的平方）限制了选择的发生，限制了近交衰退的程度。为了验证这些假设，我们种植自交和杂交油菜种子到一个因子实验，不同的植物密度和盐水胁迫。然后我们重复了这个实验，降低了盐的浓度。我们观察到相当大的近交衰退，特别是在第一个实验中的生存和第二个实验中的生长。这两种压力独立压抑植物的性能。不同环境下的近亲繁殖抑郁症和反应规范的家庭数量不同。异交后代有时更易变。压力对近交衰退的影响很小，而且不一致，当显着时，往往会减少它。表型变异的水平往往预测近交衰退是否会增加或减少跨环境，并在预测哪些性状显示最近交衰退特别有效。因此，我们发现很少支持压力假说和混合支持的表型变异性假说。不同水平的表型变异为近亲繁殖衰退的转变提供了一个粗略的解释，在引用更复杂的假设之前，应该进行测试。
Abstract Stressful environments are often said to increase the expression of inbreeding depression. Alternatively, Crow's “opportunity for selection” (the squared phenotypic coefficient of variation) sets a limit to how much selection can occur, constraining the magnitude of inbreeding depression. To test these hypotheses, we planted self- and cross-fertilized seeds of Brassica rapa into a factorial experiment that varied plant density and saline watering stresses. We then repeated the experiment, reducing the salt concentration. We observed considerable inbreeding depression, particularly for survival in the first experiment and growth in the second. Both stresses independently depressed plant performance. Families differed in their amounts of inbreeding depression and reaction norms across environments. Outcrossed progeny were sometimes more variable. Stresses had small and inconsistent effects on inbreeding depression and, when significant, tended to diminish it. Levels of phenotypic variability often predicted whether inbreeding depression would increase or decrease across environments and were particularly effective in predicting which traits display the most inbreeding depression. Thus, we find little support for the stress hypothesis and mixed support for the phenotypic variability hypothesis. Variable levels of phenotypic variation provide a parsimonious explanation for shifts in inbreeding depression that should be tested before invoking more complex hypotheses.
DOI：
10.1073/pnas.060284797
发表时间：
2000-03-28
影响因子：
11.1
作者：
Meagher, S;Penn, DJ;Potts, WK
通讯作者：
Potts, WK
影响因子：
3.3
作者：
D. Houle
通讯作者：
D. Houle
自交火炬松家族胚胎期近交衰退的全基因组特征。
影响因子：
3.3
作者：
Remington,DL;O'Malley,DM
通讯作者：
O'Malley,DM