气孔调节在作物适应不同水分环境中起着重要作用，为了阐明作物在不同沟灌措施下的气孔活动规律，在大田分区试验中研究了交替非充分供水与常规沟灌下玉米叶片气孔阻力差异及气孔对水汽传导的贡献。结果表明，在叶片尺度上，玉米叶片气孔阻力自叶基至叶尖处梯度递减；在群体上，叶片气孔阻力自冠层上层向下层呈垂直递增趋势；群体上层叶片气孔阻力相对较小。玉米叶片正面气孔对CO2和水汽的传导贡献大于反面；除玉米苗期外，气孔对CO2和水汽传导贡献的80%以上来自于冠层上、中部叶片。在玉米营养生长阶段，不同叶序的叶片气孔阻力随叶龄的增大而增大，交替非充分供水加大了不同叶龄叶片之间的气孔阻力差异。在玉米生殖生长阶段，较为成熟的玉米叶片气孔阻力受叶龄的影响不明显。与常规沟灌比较，交替非充分供水增大了叶片反面气孔收缩程度，对水分亏缺反应更为敏感，冠层由顶叶至底叶的叶片气孔阻力呈垂直梯度递增，引起气孔导度快速衰减，从而提高了群体上层气孔对水汽的传导贡献。因此，玉米气孔阻力大小受到沟灌方式和土壤水分状况的调控，还与叶龄、叶面积指数等环境因素及气孔自身特性有关，其研究对控制灌溉及土壤-植物-大气连续体（Soil-plant-atmosphere continuum，SPAC）水汽循环研究具有理论意义。%Stomatal regulation plays a pivotal role in the adaption of plants to different water conditions. In order to understand characteristics of stomatal resistance of crops with different irrigation methods, differences in leaf stomatal resistance and contribution of stomatal aperture to water vapor transfer were investigated with a field experiment conducted under alternative deficit water supply and under conventional furrow irrigation. Results indicated that for individual maize leaf, regardless of irrigation methods, the stomatal resistance decreased gradually from the base to the tip of the maize leaf. At the population level, the stomatal resistance of maize leaf increased gradually from canopy top to bottom. For the change of the leaf stomatal resistance in time, diurnal variation of leaf stomatal resistance was in a Wshape. Diurnal and daily changes in the leaf stomatal resistance in the upper canopy were relatively small. The upper surface of maize leaf contributed more to CO2 and water vapor transfer than the ones underside. Except at the seedling stage, the leaves in the upper and middle part of maize canopy contributed more than 80% of the total CO2 and water vapor. Stomatal resistances of maize leaves decreased with the increase in leaf age during the vegetative growth stage. Differences in stomatal resistance among maize leaves of different ages were increased by the alternative deficit water supply. During the reproductive growth phase, leaf age had no significant influence on the stomatal resistance in matured leaves. Compared with the conventional furrow irrigation with sufficient water supply, the alternative deficit water supply increased the ratio of the stomatal resistances between the upper side and underside of maize leaves. The vertical gradient of stomatal resistance from canopy top to bottom increased significantly (P<0.05), decreasing leaf stomatal conductivity rapidly, and improving the contribution of the stomatal aperture in the upper canopy to water vapor transfer. Therefore, the leaf stomatal resistance of maize was regulated by furrow irrigation methods and soil water condition, and it was affected by the leaf age, leaf area index and natural feature of stomatal aperture. The study is useful for controllable irrigation technology and water vapor cycle in soil plant atmosphere continuum (SPAC).
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