Elevated CO₂ concentration affects plant responses to drought, but its effects on poststress recovery for perennial grass species with different growth habits are unclear. The objective was to determine how stoloniferous and bunch-type grass species may exhibit differential responses to elevated CO₂ concentration during drought stress and postdrought recovery upon rewatering due to different growth characteristics. Stoloniferous creeping bentgrass (Agrostis stolonifera L.) ‘Penncross’ and bunch-type tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] ‘Sitka’ were grown at ambient CO₂ (400 μl L⁻¹) or elevated CO₂ concentration (800 μl L⁻¹) repeated in four growth chambers for 28 d, subsequently subjected to either irrigation (control) or drought stress (irrigation completely withheld) for 28 d, and then rewatered for 18 d. During drought stress, both species exposed to elevated CO₂ maintained higher turf quality, leaf water content, and membrane stability than plants at ambient CO₂. Elevated CO₂ caused significant increases in the viability of stolon–node meristematic tissues in creeping bentgrass under drought stress and rapid regeneration of daughter plants during rewatering, as shown by increased shoot biomass and percent turfgrass cover. Elevated CO₂ had no significant effects on the viability of crowns with meristematic tissues in tall fescue during drought nor shoot biomass or percent turfgrass cover during rewatering. The stoloniferous grass species was more responsive to elevated CO₂ compared to bunch-type species for poststress recovery, as creeping bentgrass rapidly regrew and recovered from drought damages. Such information is of great importance for making appropriate turfgrass selections and breeding improvements in growth habits in areas with prolonged drought and the anticipated rising CO₂ levels.

中文翻译：

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不同生长特性的草坪草物种干旱后恢复对二氧化碳升高的响应

CO ₂浓度升高会影响植物对干旱的反应，但其对具有不同生长习性的多年生草种的胁迫后恢复的影响尚不清楚。目的是确定匍匐茎和束状草种在干旱胁迫和干旱后恢复期间由于不同的生长特征对升高的 CO ₂浓度可能表现出不同的响应。匍匐匍匐翦股颖 ( Agrostis stolonifera L.) 'Penncross' 和束型高羊茅 [ Schedonorus arundinaceus (Schreb.) Dumort] 'Sitka' 在环境 CO ₂ (400 μl L ^-1 ) 或升高的 CO ₂浓度 (800微升^-1) 在四个生长室中重复 28 天，随后进行灌溉（对照）或干旱胁迫（完全停止灌溉）28 天，然后再浇水 18 天。在干旱胁迫期间，与环境 CO _{2 下的}植物相比，暴露于升高的 CO _{2 的}两个物种都保持了更高的草坪质量、叶片含水量和膜稳定性。升高的 CO ₂导致匍匐翦股颖在干旱胁迫下的匍匐茎-节分生组织的活力显着增加，并且在再浇水期间子代植物的快速再生，如增加的枝条生物量和草坪覆盖率百分比所示。升高的 CO ₂对干旱期间高羊茅中具有分生组织的冠的生存能力没有显着影响，在再浇水期间对枝条生物量或草坪覆盖率也没有显着影响。由于匍匐翦股颖迅速再生并从干旱损害中恢复，匍匐茎草物种与束状物种相比对升高的 CO ₂更敏感，以用于后应激恢复。这些信息对于在长期干旱和预期 CO ₂水平上升的地区进行适当的草坪草选择和生长习性的育种改进非常重要。