Photosynthetic response and nitrogen use efficiency of sugarcane under drought stress conditions with different nitrogen application levels
Photosynthetic response and nitrogen use efficiency of sugarcane under drought stress conditions with different nitrogen application levels
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DOI：
10.1080/1343943x.2017.1371570
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发表时间：
2017-09
影响因子：
2.5
通讯作者：
T. Dinh;Kenta Watanabe;H. Takaragawa;Mai Nakabaru;Y. Kawamitsu
中科院分区：
文献类型：
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作者：
T. Dinh;Kenta Watanabe;H. Takaragawa;Mai Nakabaru;Y. Kawamitsu
摘要 干旱胁迫是甘蔗生产的制约因素之一，干旱胁迫常发生在生育前期。在本研究中，研究了甘蔗对干旱和施氮的响应的生理和农艺特性。在裂区设计中指定了两种水分状况（移栽后 60 至 120 天的充足浇水和干旱胁迫）和四种氮水平（0、4.4、8.8 和 13.2 g pot−1 分别相当于 0、90、180 和 270 kg ha−1）。结果表明，施肥处理和未施肥处理的甘蔗对光强度和细胞间CO2浓度的光合反应存在差异。正常情况下，180 和 270 N 处理的光合速率显着高于 90 N，但在干旱条件下不显着。两种条件下0 N处理的光合速率均最低。由于叶片中积累的氮浓度较高，较高的施氮量支持较高的光合速率、气孔导度和叶绿素含量。干旱显着降低了潜在光合速率、气孔导度、SPAD、叶面积和生物量产量。较高的施氮量和较大的根系可以支持较高的光合作用活动，从而积累更多的干物质。光合和生物量氮利用效率与耐旱指数之间的强正系数可能表明较高的氮利用效率可以帮助植物具有更高的耐受干旱胁迫的能力。
Abstract Drought stress which often occurs during early growth stage is one constraint in sugarcane production. In this study, the response of sugarcane to drought and nitrogen application for physiological and agronomical characteristics was investigated. Two water regimes (well-watered and drought stress from 60 to 120 day after transplanting) and four nitrogen levels (0, 4.4, 8.8 and 13.2 g pot−1 equivalent to 0, 90, 180 and 270 kg ha−1, respectively) were assigned in a Split-plot design with three replications. The results showed that photosynthetic responses to light intensity and intercellular CO2 concentrations of sugarcane were different between fertilized and non-fertilized treatments. Photosynthetic rates of 180 and 270 N treatments, normally, were significantly higher than that of 90 N, but not significant at drought conditions. Photosynthetic rates of 0 N treatment were the lowest under both conditions. Higher nitrogen application supported higher photosynthetic rate, stomatal conductance, and chlorophyll content because of higher nitrogen concentration accumulated into the leaf. Drought significantly reduced the potential photosynthetic rate, stomatal conductance, SPAD, leaf area, and biomass production. Higher nitrogen applications with larger root system could support higher photosynthetic activities to accumulate more dry mass. Strong positive coefficient between photosynthetic and biomass nitrogen use efficiency and drought tolerance index may suggest that higher nitrogen use efficiency could help plants have higher ability to tolerate drought stress.