Photosynthetic performance and growth traits in Pennisetum centrasiaticum exposed to drought and rewatering under different soil nutrient regimes
Photosynthetic performance and growth traits in Pennisetum centrasiaticum exposed to drought and rewatering under different soil nutrient regimes
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DOI：
10.1007/s11738-013-1419-2
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发表时间：
2014-02
影响因子：
2.6
通讯作者：
Yayong Luo;Xueyong Zhao;H. Qu;X. Zuo;Shaokun Wang;Wenda Huang;Yongqing Luo;Min Chen
中科院分区：
文献类型：
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作者：
Yayong Luo;Xueyong Zhao;H. Qu;X. Zuo;Shaokun Wang;Wenda Huang;Yongqing Luo;Min Chen
植物对干旱和复水的反应已经有了很好的记录，然而，关于沙生植物在不同土壤养分条件下对干旱和复水的反应却知之甚少。在这项研究中，狼尾草centrasiaticum在两种土壤养分制度进行了逐步干旱和随后的复水。通过测定土壤水分状况、气体交换特性、叶绿素a荧光特性以及生物量等指标，研究了不同施肥处理对土壤水分状况、气体交换特性以及生物量的生理生态响应。净光合速率（Pn），气孔导度（GS），水分利用效率，光合系统II的最大量子效率（PSII，FV/FM），电子传递通量每横截面（ET 0/CS 0），并在横截面的基础上的性能指数（PICS）在干旱期间的两种营养制度受到抑制。与此同时，叶片胞间CO2浓度（Ci）、最小荧光强度（F0）和单位面积耗散能通量（DI 0/CS 0）增加。PSII光化学的可逆下调和过量激发能（DI 0/CS 0）的热耗散增强有助于增强干旱胁迫下植物的光保护。因此，这些结果表明，在极端干旱事件中，中甸杨是有能力承受和生存的，在两种营养制度下，胁迫下的中甸杨的恢复模式是相似的。但施肥增加了干旱期的生物量，增加了气体交换和叶绿素a荧光特性的变化。此外，施肥加速了干旱进程，加重了极端干旱事件下的胁迫。因此，施肥策略中使用的P. centrasiaticum恢复应仔细选择施肥可能并不总是有益的。
Responses of plants exposed to drought and rewatering have been well documented; however, little is known concerning strategies of psammophyte to drought and rewatering under different soil nutrient regimes. For this study, Pennisetum centrasiaticum under two soil nutrient regimes was subjected to progressive drought and subsequent rewatering. Soil water status, gas exchange characteristics, chlorophyll a fluorescence characteristics as well as biomass traits were measured to investigate ecophysiological responses. Net photosynthesis rate (Pn), stomatal conductance (gs), water use efficiency, maximum quantum efficiency of photosynthesis system II (PSII, FV/FM), electron transport flux per cross section (ET0/CS0), and performance index on cross section basis (PICS) were suppressed during drought periods for both nutrient regimes. Meanwhile, leaf intercellular CO2 concentration (Ci), minimal fluorescence intensity (F0), and dissipated energy flux per cross section (DI0/CS0) increased. Reversible downregulation of PSII photochemistry and enhanced thermal dissipation of excess excitation energy (DI0/CS0) contributed to enhanced photo-protection in drought-stressed plants. Thus, the results indicate that P. centrasiaticum is capable of withstanding and surviving extreme drought events, and the recovery pattern of stressed P. centrasiaticum under both nutrient regimes was similar. However, fertilization increased the biomass and the variation in gas exchange and chlorophyll a fluorescence characteristics during drought periods. Additionally, fertilization accelerated the process of drought and aggravated stress under extreme drought events. Thus, the fertilization strategy used in P. centrasiaticum restoration should be carefully selected—fertilization may not always be beneficial.