Differentiation of Life-History Traits among Palmer Amaranth Populations (Amaranthus palmeri) and Its Relation to Cropping Systems and Glyphosate Sensitivity
Differentiation of Life-History Traits among Palmer Amaranth Populations (Amaranthus palmeri) and Its Relation to Cropping Systems and Glyphosate Sensitivity
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DOI：
10.1017/wsc.2017.14
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发表时间：
2017-05-01
期刊：
影响因子：
2.5
通讯作者：
Wood, C. Wesley
中科院分区：
文献类型：
--
作者：
Bravo, Washington;Leon, Ramon G.;Wood, C. Wesley
人们已经广泛研究了紫红色棕榈对不同除草剂进化抗性的能力，但关于这种杂草物种可能如何进化出其他可能使其更具攻击性和更难控制的生活史特征的信息很少。我们研究了在佛罗里达和佐治亚州采集的10个紫红色植物种群的生长和形态变异，这些种群来自不同种植历史的田地，从连续的短作物(蔬菜和花生)到高大作物(玉米和棉花)，从密集使用除草剂的历史到有机生产。在鲜重和干重、开花天数、株高、叶片和冠层形状等多个性状上，紫红色居群存在差异。群体间这些性状的差异从36%到87%不等。虽然从包括GR作物在内的种植系统中收集的抗草甘膦(GR)群体的上述变量值高于对草甘膦敏感(GS)的群体，但性状的变异不能用草甘膦抗性或群体间的距离来解释。作物轮作和作物冠层结构等种植制度成分较好地解释了种群间的差异。与GS群体相比，GR群体较高的增长可能是其种植制度中存在的多重选择力量的结果，而不是草甘膦抗性性状的多效性效应。结果表明，紫红色紫红色可以进化出生活史特征，增加其在种植系统中的生长和繁殖潜力，这就是为什么它在美国迅速传播的原因。此外，我们的发现强调了考虑轮作结构和使用更具竞争力的作物的进化后果的必要性，这可能会促进在具有高遗传变异性的杂草物种中选择更具攻击性的生物型。
Palmer amaranth's ability to evolve resistance to different herbicides has been studied extensively, but there is little information about how this weed species might be evolving other life-history traits that could potentially make it more aggressive and difficult to control. We characterized growth and morphological variation among 10 Palmer amaranth populations collected in Florida and Georgia from fields with different cropping histories, ranging from continuous short-statured crops (vegetables and peanut) to tall crops (corn and cotton) and from intensive herbicide use history to organic production. Palmer amaranth populations differed in multiple traits such as fresh and dry weight, days to flowering, plant height, and leaf and canopy shape. Differences between populations for these traits ranged from 36% up to 87%. Although glyphosate-resistant (GR) populations collected from cropping systems including GR crops exhibited higher values of the aforementioned variables than glyphosate-susceptible (GS) populations, variation in traits was not explained by glyphosate resistance or distance between populations. Cropping system components such as crop rotation and crop canopy structure better explained the differences among populations. The higher growth of GR populations compared with GS populations was likely the result of multiple selection forces present in the cropping systems in which they grow rather than a pleiotropic effect of the glyphosate resistance trait. Results suggest that Palmer amaranth can evolve life-history traits increasing its growth and reproduction potential in cropping systems, which explains its rapid spread throughout the United States. Furthermore, our findings highlight the need to consider the evolutionary consequences of crop rotation structure and the use of more competitive crops, which might promote the selection of more aggressive biotypes in weed species with high genetic variability.