Agricultural Biotechnology Lab, Department of Plant Science, University of Connecticut, Storrs, Connecticut, United States of America.
PLoS One. 2012;7(12):e50643. doi: 10.1371/journal.pone.0050643. Epub 2012 Dec 4.
Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB) and redtop (RT), where the glyphosate resistance (GR) trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities.
杂草生态型和作物物种（包括草坪草）中的除草剂抗性越来越普遍，但目前知识上的差距限制了预测性生态风险评估和风险管理计划。本项目研究了每年施用草甘膦对两种野生弯叶画眉草（匍匐弯叶画眉草和红顶画眉草）的营养生长和生殖潜力的影响，其中弯叶画眉草植株在施用草甘膦时被覆盖以模拟草甘膦抗性（GR）性状。在通常有野生弯叶画眉草栖息的五个野外样地中进行了研究，包括农业干草田、自然草地和荒地。结果表明，与未施药样地中的弯叶画眉草相比，每年施用草甘膦处理可提高弯叶画眉草的存活率、营养生长和生殖潜力。在第二年的生长中，与对照相比，红顶画眉草在施药样地中的花数增加了 86 倍，而匍匐弯叶画眉草增加了 20 倍。在三年研究结束时，与对照相比，在干草田和草地样地的施药样地中，植物群落组成发生了变化。施药样地的土壤中硝酸盐浓度高于对照。这是首次在弯叶画眉草植株中模拟 GR 性状的研究，目的是量化弯叶画眉草对草甘膦选择压力的反应，并了解对周围植物群落的影响。
