Gage Karla L, Gibson David J, Young Bryan G, Young Julie M, Matthews Joseph L, Weller Stephen C, Wilson Robert G
Department of Plant, Soil, and Agricultural Systems Southern Illinois University Carbondale Illinois 62901 ; Department of Plant Biology Center for Ecology Southern Illinois University Carbondale Illinois 06460.
Department of Plant Biology Center for Ecology Southern Illinois University Carbondale Illinois 06460.
Ecol Evol. 2015 Sep 4;5(18):4161-73. doi: 10.1002/ece3.1667. eCollection 2015 Sep.
Agricultural environments allow study of evolutionary change in plants. An example of evolution within agroecological systems is the selection for resistance to the herbicide glyphosate within the weed, Conyza canadensis. Changes in survivorship and reproduction associated with the development of glyphosate resistance (GR) may impact fitness and influence the frequency of occurrence of the GR trait. We hypothesized that site characteristics and history would affect the occurrence of GR C. canadensis in field margins. We surveyed GR occurrence in field margins and asked whether there were correlations between GR occurrence and location, crop rotation, GR crop trait rotation, crop type, use of tillage, and the diversity of herbicides used. In a field experiment, we hypothesized that there would be no difference in fitness between GR and glyphosate-susceptible (GS) plants. We asked whether there were differences in survivorship, phenology, reproduction, and herbivory between 2 GR and 2 GS populations of C. canadensis in agrestal and ruderal habitats. We found that geographic location was an important factor in the occurrence of GR C. canadensis in field margins. Although not consistently associated with either glyphosate resistance or glyphosate susceptibility, there were differences in phenology, survivorship, and herbivory among biotypes of C. canadensis. We found equal or greater fitness in GR biotypes, compared to GS biotypes, and GR plants were present in field margins. Field margins or ruderal habitats may provide refugia for GR C. canadensis, allowing reproduction and further selection to occur as seeds recolonize the agrestal habitat. Agricultural practices may select for ecological changes that feed back into the evolution of plants in ruderal habitats.
农业环境有助于研究植物的进化变化。农业生态系统内进化的一个例子是杂草加拿大飞蓬对除草剂草甘膦抗性的选择。与草甘膦抗性（GR）发展相关的生存和繁殖变化可能会影响适合度，并影响GR性状的出现频率。我们假设，场地特征和历史会影响田间边缘GR加拿大飞蓬的出现。我们调查了田间边缘GR的出现情况，并询问GR的出现与位置、作物轮作、GR作物性状轮作、作物类型、耕作方式以及所用除草剂的多样性之间是否存在相关性。在一项田间试验中，我们假设GR植物和草甘膦敏感（GS）植物之间的适合度没有差异。我们询问了在农田和荒地生境中，2个GR和2个GS加拿大飞蓬种群在生存、物候、繁殖和食草方面是否存在差异。我们发现地理位置是田间边缘GR加拿大飞蓬出现的一个重要因素。虽然加拿大飞蓬的生物型在物候、生存和食草方面存在差异，但这些差异与草甘膦抗性或草甘膦敏感性并不始终相关。我们发现，与GS生物型相比，GR生物型具有同等或更高的适合度，并且田间边缘存在GR植物。田间边缘或荒地生境可能为GR加拿大飞蓬提供避难所，随着种子重新定殖到农田生境，使其得以繁殖并进一步进行选择。农业实践可能会选择导致生态变化的因素，这些变化又会反馈到荒地生境中植物的进化过程中。
