Genetic Basis of Plant Interactions

现在很明显，自然种群的遗传变异比20年前开始电泳学研究之前预期的要多得多。理论工作已经阐明了哪些过程可能是维持如此庞大的基因变异的潜在原因，但在许多不寻常的情况下，还没有足够的实验工作来证明实际的机制。拟议的研究将调查维持遗传变异的一种特殊机制的重要性：结合环境反应中基于遗传的变异的局部变异选择过程。特别是，将记录单个植物因邻近植物的密度和组成而产生的遗传变异的大小和性质。这些研究将能够预测在不同生物环境下对选择的反应。这样的预测将与在选择实验中观察到的反应进行比较。由于生物环境中的自然变异在野生种群中普遍存在，这些研究的结果可能会对局部变异选择的普遍重要性产生影响。这项工作的重点物种包括一个本地物种和一个引进物种。因此，这一系统可作为阐明外来物种入侵野生群落后物种间相互作用演变的模型，并可为在这种引入后加强本土群落成功的方法提供洞察。

It is now evident that natural populations harbor far more genetic variation than was expected prior to initiation of electrophoretic studies 20 years ago. Theoretical work has clarified what processes may potentially be responsible for the maintenance of such vast stores of genetic variation, but there has been insufficient experimental work to demonstrate the actual mechanisms in more than a few unusual cases. The proposed studies will investigate the importance of a particular mechanism for maintaining genetic variation: the process of locally varying selection in conjunction with genetically based variation in environmental response. In particular, the magnitude and nature of genetic variation of individual plants in response to the density and composition of neighboring plants will be documented. These studies will permit prediction of the response to selection under differing biotic environments. Such predictions will be compared with observed responses in selection experiments. Because natural variation in the biotic environment is ubiquitous in wild populations, the findings of these studies may have bearing on the general importance of locally varying selection. The focal species for this work include one native and one introduced species. This system may therefore serve as a model for elucidating the evolution of interactions between species following invasions of exotics into wild communities and may provide insights into methods for enhancing the success of native communities following such introductions.