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【目的】明确‘中山杉407’(Taxodium‘Zhongshanshan407’)在完全淹水胁迫解除后的生长和光合特性,为三峡库区消落带等湿地生态系统恢复与构建中的植被选择提供依据。【方法】以‘中山杉407’2年生苗为试验材料,设置全淹(S)和对照(CK)2个处理,其中S处理的植株预先经过3个月的完全淹水胁迫。淹水胁迫解除后,使用LI-6400 XT气体交换系统和OS1p便携式调制荧光仪测定两处理植株的光合作用参数和叶绿素荧光参数,并于植株恢复生长10个月后,测定其生长指标。【结果】淹水阶段结束后,S组植株的净光合速率(P_n)、气孔导度(G_s)和蒸腾速率(T_r)显著高于对照(CK)组植株,而S组的水分利用效率(E_(WUE))低于CK组。同时,‘中山杉407’维持一定的叶绿素荧光水平,S组和CK组的可变荧光(F_v)、PSⅡ潜在活性(F_v/F_0)、PSⅡ最大光量子产额(F_v/F_m)、实际量子产量(Ф_(PSⅡ))和电子传递速率(V_(ETR))均没有显著差异。经过10个月的恢复,S组‘中山杉407’的总干质量、地上部分生物量与CK组无显著差异。【结论】完全淹水胁迫解除后,‘中山杉407’能够通过合理调整生长和光合策略,表现出良好的适应性,是适宜于三峡库区消落带等淹水环境生态修复工程实践的优良树种。
【Objective】 The objective of this study is to clarify the growth and photosynthetic characteristics of ’Taxodium’ Zhongshanshan407 ’after complete flooding stress relief, and provide the basis for the vegetation restoration in ecosystem restoration and construction of the hydro-fluctuation belt in the Three Gorges Reservoir Area. 【Method】 Two treatments of ’Zhongshanshan 407’ 2-year-old seedlings were used as experimental materials. Two treatments of full flooding (S) and control (CK) were set up, and the S-treated plants were completely flooded for 3 months. After the flooding stress was relieved, the photosynthesis parameters and chlorophyll fluorescence parameters of two treatment plants were measured by LI-6400 XT gas exchange system and OS1p portable modulation fluorescence instrument. The growth indexes were measured after 10 months of plant growth recovery. 【Result】 The results showed that the net photosynthetic rate (P_n), stomatal conductance (G_s) and transpiration rate (T_r) of S plants were significantly higher than those of CK after the flooding stage. However, the water use efficiency E_ (WUE)) is lower than CK group. At the same time, ’Zhongshanshan 407’ maintained a certain level of chlorophyll fluorescence. The fluorescence (F_v), the potential activity of PSⅡ (F_v / F_0), the maximum photochemical quantum yield of PSⅡ (F_v / F_m) and the actual quantum yield (Ф PSII) and electron transfer rate (V ETR)) were not significantly different. After 10 months of recovery, the total dry mass of the ’Zhongshanshan 407’ group in S group was not significantly different from that in CK group. 【Conclusion】 After being completely flooded, ’Zhongshanshan 407’ can show good adaptability by adjusting growth and photosynthesis strategies reasonably, and is suitable for the practice of eco-restoration engineering such as water level fluctuation zone in the Three Gorges reservoir area. species.