干旱胁迫下水杨酸对银沙槐子叶表皮气孔开度的影响

以沙生植物银沙槐似mmodendronargenteum）幼苗为实验材料，采用PEG处理和PEG＋SA综合处理两种方式，其中SA包括不同浓度、不同时间和不NpH值3种处理，显微观察干旱胁迫处理、干旱胁迫下外源水杨酸处理对子叶表皮气孔开度的影响，以探讨干旱与气孔运动的关系。结果表明：干旱胁迫处理后，气孔运动的趋势是随着PEG浓度的增加，孔径逐渐减小。在干旱胁迫下，sA不同浓度处理后，气孔孔径在相同PEG浓度下随着sA浓度的增加而减小；随sA处理时间的不同，气孔开度随着时间的延长而变小，且在不同PEG浓度（0、10％和20％）条件下，气孔开度的变化与sA处理时间均呈显著（R=-0．998＊＊、R=-0．955＊和R=-0．983＊）负相关；sA溶液pH值越低，对气孔开度的抑制作用越明显。可见，干旱胁迫后能减小银沙槐气孔孔径的大小，在干旱胁迫处理下施加SA处理，sA对银沙槐气孔开度的抑制作用加剧，说明sA在提高银沙槐的抗旱性方面起到了一定作用。

Effect of Salicylic Acid on Stomata Aperture of Epidermis in Ammodendron argenteum Cotyled under Drought Stress

Taking Ammodendron argenteum seedlings as experimental materials, methods of PEG and PEG＋SA combined treatment were adopted. SA includes three different density, time, and pH treatment. Drought stress and drought stress to exogenous salicylic acid＇s influences on cotyledon epidermis＇ stomata aperture were ob- served by microscope in order to explore the relationship between drought and stomata movement. The results showed that after drought stress stomata movement increased and aperture decreased as the PEG density went up. In the environment of drought stress and same PEG density, stomata aperture decreased as SA density in- creased after different SA density treatment; stomata aperture decreased as SA treatment time went on and on the condition of different PEG density （0, 10% and 20%）, the change of stomata aperture and SA treatment time all showed significant negative correlation （R=-0.998＊＊, R=-0.955＊ and R=-0.983＊）. The lower pH of SA solu- tion was, the more significant inhibitional effect it had on stomata aperture. To conclude, drought stress made stomata aperture decrease. Under drought stress, treatment with SA intensified the inhibitional effect on stomata aperture. It revealed that SA had a certain effect on improving drought resistance ofA. argenteum.