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引用本文:徐建新,王潜,高阳,等.水盐胁迫对玉米茎木质部水力特性的影响 [J].灌溉排水学报,0,():-.
Xun Jian-xin,Wang Qian,Gao Yang,et al.水盐胁迫对玉米茎木质部水力特性的影响 [J].灌溉排水学报,0,():-.
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水盐胁迫对玉米茎木质部水力特性的影响
徐建新1, 王潜2, 高阳3, 孙景生3, 侯泽林2
1.华北水利水电大学 郑州;2.华北水利水电大学 郑州;3.中国农业科学院农田灌溉研究所 新乡
摘要:
【目的】探讨水盐胁迫下玉米茎木质部水力特征、光合作用和生长指标的响应,有助于深入理解水盐胁迫诱导茎木质部形成栓塞现象的机理。【方法】通过室内玉米桶栽试验,设置水分胁迫(LD)、盐分胁迫(WS)和水盐联合胁迫(SY)三个胁迫处理,以无水盐胁迫处理作为对照(CK),研究水、盐胁迫及水盐联合胁迫对玉米叶、根水势及玉米茎木质部水力特性的影响。【结果】与对照处理相比,在水、盐胁迫或水盐联合胁迫下,玉米根、叶水势均有明显降低,叶-土水势差从大到小的顺序依次为CK>LD>WS>SY;茎干的初始水力导度Ki和茎流速率明显降低,其变化趋势与叶—土系统水势差变化趋势一致,相应地茎木质部水力导度损失百分比PLC显著增高;同时,玉米叶片的净光合速率Pn、蒸腾速率Tr、气孔导度Gs呈CK>LD、WS>SY的趋势,生长指标株高和叶片长度均呈CK>LD>WS>SY的下降趋势。【结论】水、盐胁迫和水盐联合胁迫均会降低玉米水势,使植株体内渗透势平衡遭到破坏,导致玉米光合性能受到抑制,使茎木质部内产生空穴化和栓塞现象,且不同胁迫方式会导致不同程度的栓塞程度。
关键词:  水盐胁迫;水力导度;栓塞;茎流;水势;光合作用
DOI:
分类号:S513
基金项目:国家自然科学基金项目(面上项目,重点项目,重大项目)
Effects of water and salt stress on hydraulic characteristics of maize stem xylem
Xun Jian-xin,Wang Qian,Gao Yang,et al
1.North China University Of Water Resources And Electric Power,Zheng Zhou;2.Institute of Farmland Irrigation,Xin xiang
Abstract:
【Objective】Understanding the response of hydraulic characteristics, photosynthesis and growth indicators of maize stem xylem under water and salt stress is essential to unravelling the mechanism of xylem embolism induced by water and salt stress.【Method】A phytotron experiment was conducted to investigate effects of water and salt stress on maize leaf water potential, root water potential and stem hydraulic conductivity. The experiment was comprised with four treatemnts, i.e., water stress (LD), salt stress (WS), water-salt combined stress(SY), and CK (free of water and salt stress).【Result】Compared with CK, LD, WS, and SY decreased the water potential of maize root and leaf decreased obviously, the order for the water potential difference between leaf and soil shown as CK>LD>WS>SY. The initial hydraulic conductivity-Ki and sap flow rate reduced by water and salt stress significantly, and the variation trend was same with the variation trend of water potential difference between leaf and soil. Accordingly, the percentage of hydraulic conductivity loss of stem xylem-PLC increased significantly. Meanwhile, the net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) of maize leaves showed the trend of CK>LD and WS>SY, the growth indexes of plant height and leaf length showed a decreasing trend of CK>LD>WS>SY.【Conclusion】Water stress, salt stress and combined water and salt stress could reduce the water potential of maize, destroy the balance of osmotic potential in the plant, inhibit the photosynthetic performance of maize, cause cavitation and embolization in the xylem of the stem, and the different stress result in different degrees of embolization.
Key words:  Water and salt stress; hydraulic conductivity; embolism; sap flow; water potential; photosynthesis