Responses of leaf gas exchange rate to acute soil drying in Jatropha curcas L
Responses of leaf gas exchange rate to acute soil drying in Jatropha curcas L
复制标题
麻疯树叶片气体交换率对土壤急性干燥的响应
DOI：
10.1080/1343943x.2020.1730699
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发表时间：
2020
影响因子：
2.5
通讯作者：
Kawamitsu Yoshinobu
中科院分区：
文献类型：
--
作者：
Nakabaru Mai;Hoang Dinh T.;Watanabe Kenta;Takaragawa Hiroo;Yabuta Shin;Ueno Masami;Kawamitsu Yoshinobu
为了在半干旱地区种植麻疯树这种生物能源作物，发展节水灌溉系统至关重要。在本研究中，为了确定有效灌溉系统的有用参数，在日本冲绳的温室条件下，在盆栽和根箱中种植麻风树。在移栽后6 ~ 9个月，我们测量了持续土壤水分亏缺期间的气体交换速率，并试图通过基于气孔的内在水分利用效率（A/gs）和基于非气孔限制的羧化效率（A/Ci）的变化来确定土壤基质势（pF）的阈值。停止灌溉后，aandgs开始下降，在pF 4.0时各参数均为零。而氮素对土壤水分亏缺的敏感性高于氮素。复水后气孔开度和碳吸收量恢复到水分胁迫处理前的水平。在pF 3.5及更高值（表示更严重的水分胁迫）时，A/ gss倾向于增加，而A/ gss则急剧下降。这些结果表明，土壤中pF约为3.5是麻疯树光合速率非气孔限制的阈值，可作为节水灌溉系统的再浇水点。缩写：aco2同化速率；Ci：细胞间co2浓度；E：蒸腾速率；Gs：气孔导度；pF：土壤基质电位；PFD：光子通量密度；时域反射法；VPD：叶片与空气的蒸气压差；VWC：体积含水量。
Development of a water-efficient irrigation system is essential in order to cultivateJatropha curcas, a bioenergy crop, in semiarid regions. In the present study, to determine the useful parameter for the efficient irrigation system, jatropha plants were grown in pots and root boxes under greenhouse conditions in Okinawa, Japan. At 6 to 9 months after transplanting, we measured the gas exchange rate during ongoing soil water deficits and attempted to identify the threshold of soil matric potential (pF) with changes of both intrinsic water use efficiency (A/gs) as a stomatal-based index and carboxylation efficiency (A/Ci) as an index of non-stomatal limitation. When irrigation was stopped,Aandgsbegan to decline, with each parameter reaching zero at pF 4.0. However,gswas more sensitive to soil water deficits thanA. After re-watering, stomatal openings and carbon uptake recovered to the value observed before water stress treatment. At pF 3.5 and higher values (representing more severe water stress),A/gsintended to increase andA/Cisharply decreased. These results suggested that approximately pF 3.5 in the soil was the threshold of non-stomatal limitations to photosynthetic rate and should be useful to the re-watering point for the water-efficient irrigation system in jatropha.Abbreviations: ACO2assimilation rate;Ci: intercellular CO2concentration;E: transpiration rate;gs: stomatal conductance; pF: soil matrix potential; PFD: photon flux density; TDR: time domain reflectometry; VPD: leaf-to-air vapor pressure difference; VWC: volumetric water content.