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作 者 ：金江群, 郭泉水, 朱莉, 许格希, 刘建锋, 裴顺祥

期 刊 ：植物科学学报 2012年 30卷 6期 页码：599-610

关键词：光合特性；复水；崖柏；干旱胁迫；水分利用效率；

Keywords:Photosynthetic characteristics, Recovery, Thuja sutchuenensis, Drought stress, Water use efficiency,

摘 要 ：以4年生崖柏(Thuja sutchuenensis Franch.)盆栽实生苗为材料,试验干旱和复水对崖柏光合特性及水分利用效率的影响。结果显示,在自然干旱处理过程中,叶片相对含水量(LRWC)在土壤相对含水量(SRWC)降至30%之后开始出现下降;净光合速率(P_n)、蒸腾速率(T_r)、胞间CO₂浓度(C_i)、光饱和点(LSP)和最大光合速率(P_max)随着土壤可利用水分的减少而逐渐降低;而表观量子效率(Q)、表观量子需要量(1/Q)及光补偿点(LCP)未发生明显变化;水分利用效率(WUE)则随着SRWC的下降而逐渐提高。在停止浇水50 d后(SRWC下降约95%),叶片萎蔫,净光合速率接近零,复水后3 d,净光合速率(P_n)恢复至对照的88.59%,WUE降至对照的88.63%。通过干旱-复水一系列生理指标的变化分析认为,崖柏为干旱避免型植物。

Abstract:Photosynthetic characteristics and water use efficiency (WUE) were monitored in four year old seedlings of Thuja sutchuenensis Franch.during drought stress and recovery.Results showed that leaf relative water content (LRWC) decreased after soil relative water content (SRWC) fell below 30% under water stress.Net photosynthetic rate(P_n),transpiration rate (T_r), intercellular CO₂ concentration (C_i),light saturation point (LSP)and the maximum photosynthetic rate (P_max) decreased along with available water reduction, while apparent quantum yield (Q),apparent quantum requirement (1/Q),and light compensation point (LCP) remained.The WUE gradually increased as SRWC fell.P_n reached zero due to leaf wilting after 50 days drought stress (SRWC decreased about 95%).After three days of rewatering, P_n recovered to 88.59% of the control levels and WUE reduced to 88.63% that of the control levels.Through the analysis of physical signs above,we concluded that Thuja sutchuenensis Franch.is a drought-avoiding plant.

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