土壤水分胁迫对大叶黄杨和月季光合生理特性的影响

Soil Water Stress on Photosynthetic Physiological Characteristics in Rosa Chinensis Jacq and Euonymus Japonicus L

采用盆栽试验,研究了不同水分条件下月季和大叶黄杨的光合生理特性。结果表明:(1)随着水分胁迫的加重(W1→W2→W3),月季和大叶黄杨的主要光合参数净光合速率(Pn)、蒸腾速率(Tr)日均值均呈逐渐降低趋势;大叶黄杨的WUE逐渐降低,月季先升高后降低;月季的气孔导度(Gs)逐渐降低,大叶黄杨在中度控水处理(W2)时的Gs高于轻度控水处理(W1);月季的胞间CO2浓度(Ci)先降后升,而大叶黄杨有逐渐增加的趋势。(2)水分胁迫下,两植物叶绿素荧光参数Fo升高,最大荧光(Fm),可变荧光(Fv),Fv/Fm,Fv/Fo降低,但大叶黄杨的参数变幅均大于月季。(3)两植物主要光合参数的日变化曲线有明显不同,CK和W1时,月季的Pn和Tr为"双峰"型,大叶黄杨为"单峰"型。(4)水分胁迫下,各荧光参数和光合作用参数变化均表明,大叶黄杨对土壤水分胁迫更为敏感。

Rosa chinensis Jacq and Euonymus japonicus L were grown in pots with different levels of water stress to evaluate the effects of soil water stress on photosynthetic physiological characteristics. Results are showed as follows：（1） According to the daily average of photosynthetic parameters,the Pn and Tr of the two plants gradually decreased with the increase in water stress. The WUE of Euonymus japonicus gradually decreased,but Rosa chinensis Jacq,increased first and then decreased. The Gs of Rosa chinensis Jacq gradually decreased,while Euonymus japonicus L had higher value in moderate water stress （W2） than in mild water stress （W1）. The Ci of Rosa chinensis Jacq first decreased and then increased,while Euonymus japonicus L gradually increased. （2） The chlorophyll fluorescent parameter,Fo,increased,while Fm,Fv,Fv/Fm,and Fv/Fo decreased due to water stress,but Euonymus japonicus L had greater change than Rosa chinensis Jacq. （3） The diurnal variation curves of photosynthetic parameters of the two plants were significantly different. The diurnal variation curves of the Pn and Tr of Rosa chinensis Jacq were the double-peak type and Euonymus japonicus L,the single-peak type in normal water supply （CK） and mild water stress （W1）. （4） The changes of fluorescent parameters and photosynthetic parameters of the two plants under water stress revealed that Euonymus japonicus L was more sensitive to soil water stress than Rosa chinensis Jacq.