The growth response of annual sowthistle (Sonchus oleraceus L.) to anticipated future climate conditions is currently unknown, and thus two parallel studies were conducted dealing with glyphosate-resistant (GR) and glyphosate-susceptible (GS) biotypes of S. oleraceus. The glyphosate efficacy study was conducted using different doses of glyphosate (0 [control], 180, 360, 720 [recommended dose], and 1,440 g ae ha−1) at two different moisture levels (well-watered and water-stressed conditions). In the second study, the growth and seed production of these biotypes were studied under different atmospheric carbon dioxide (CO2) concentrations (450 and 750 ppm) and under well-watered (100% field capacity) and water-stressed (50% field capacity) conditions. Results showed that the GR biotype survived (>68%) at 1,440 g ha−1, but for the GS biotype, no plant survived, and both biotypes were slightly (<10%) affected by moisture regimes. In the elevated CO2 condition, the GS biotype plants were >38% taller and produced >44%, >18%, and >21% more leaves, buds, and seeds, respectively, compared with the ambient CO2 concentration under both moisture regimes. The biomass also increased by 27% in comparison with the ambient CO2 concentration. For the GR biotype, plants at the elevated CO2 level, while they also grew 38% taller in comparison with the ambient CO2 concentration, the numbers of leaves, buds, and seeds and biomass were not affected by this increase in CO2. Results showed that there were minimal changes in response to glyphosate for GR and GS biotypes of S. oleraceus with or without moisture stress. Our study suggests that future climate change with elevated CO2 levels can affect the response of S. oleraceus to glyphosate, and such knowledge will be helpful for weed management in the future.

中文翻译：

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抗草甘膦和易受草甘膦影响的一年生水飞蓟（Sonchus oleraceus）生物型对二氧化碳增加和土壤水分变化的响应

一年生水飞蓟的生长反应 (苦参L.) 对预期的未来气候条件的影响目前尚不清楚，因此针对草甘膦抗性 (GR) 和草甘膦敏感性 (GS) 生物型进行了两项平行研究。苦苣菜. 草甘膦功效研究是使用不同剂量的草甘膦（0 [对照]、180、360、720 [推荐剂量]和 1,440 g ae ha-1) 在两种不同的湿度水平（充分浇水和缺水条件）下。在第二项研究中，研究了这些生物型在不同大气二氧化碳（CO2) 浓度（450 和 750 ppm）以及在水分充足（100% 田间容量）和缺水（50% 田间容量）条件下。结果表明 GR 生物型在 1,440 g ha 时存活（>68%）-1，但对于 GS 生物型，没有植物存活，并且两种生物型都受到水分状况的轻微影响（<10%）。在升高的 CO2条件下，与环境 CO2 相比，GS 生物型植物高 > 38%，并分别产生 > 44%、> 18% 和 > 21% 的叶子、芽和种子2两种水分状态下的浓度。与环境二氧化碳相比，生物量也增加了 27%2浓度。对于 GR 生物型，CO 升高的植物2水平，同时与环境中的二氧化碳相比，它们也增长了 38%2浓度、叶、芽、种子和生物量的数量不受二氧化碳增加的影响2. 结果表明，对于 GR 和 GS 生物型，草甘膦的反应变化很小。苦苣菜有或没有水分压力。我们的研究表明，随着二氧化碳浓度升高，未来的气候变化2水平会影响反应苦苣菜草甘膦，这些知识将有助于未来的杂草管理。