DISSERTATION RESEARCH: Does Crop-to-Wild Hybridization Shift Life History Toward Increased Invasiveness?

杂草和入侵植物通常会经历与它们的前辈不同的环境，它们可能需要进化的变化才能在新的栖息地生存。 当入侵者是两个物种的杂交后代时，这种变化可能最为明显，因为它们代表了父母特征的混合体。 利用杂草萝卜（萝卜）和作物（萝卜）之间的作物-杂草杂交，研究生将研究杂交种群的“进化性”。 具体而言，本论文的研究方向为：1.测量实验种群中杂草萝卜繁殖时间和繁殖时平均大小的变化，有和没有杂交。 2.通过比较常见的花园实验中不同的选择谱系，确定植物繁殖时间和繁殖时大小的遗传变异如何影响其杂草性。发育性状的变化可能对杂草性的进化产生重大影响。 以一种新颖的方式，杂交种可能能够受益于父母双方的性状，也许比父母中的任何一方都要杂草丛生。 因此，杂交可能是入侵的刺激。这项研究将提高我们对杂草进化的理解，为关注入侵物种、农业杂草及其对生物多样性影响的土地管理者提供重要见解。

Weedy and invasive plants often experience different environments than their predecessors, and evolutionary changes may be needed for them to survive in new habitats. Such shifts may be most pronounced when invaders are the hybrid offspring of two species, because they represent a mixture of their parents' traits. Using crop-weed hybrids between weedy radish (Raphanus raphanistrum) and the crop (Raphanus sativus), the graduate student will examine the "evolvability" of hybridizing populations. Specifically, the proposed dissertation research will:1. Measure shifts in the time to reproduction and the average size at reproduction of weedy radishes in experimental populations, with and without hybridization. 2. Determine how genetic variation in the plants' time to reproduction and size at reproduction affects their weediness by comparing different selected lineages in common garden experiments Changes in developmental traits may have major implications for the evolution of weediness. In a novel way, hybrids may be able to benefit from traits from both of their parental species, perhaps becoming weedier than either parent. Thus, hybridization could be stimulus for invasiveness. This research will to improve our understanding of weed evolution, providing important insights for land managers who are concerned with invasive species, agricultural weeds, and their impacts on biodiversity.