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| DOI：10.13522/j.cnki.ggps.2019300 |
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| Change in hydraulic characteristics of maize in response to water and salinity stresses |
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XU Jianxin, WANG Qian, GAO Yang, SUN Jingsheng, HOU Zelin
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1. North China University of Water Resources and Electric Power, Zhengzhou 450000, China; 2. Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang 453000, China
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| Abstract: |
| 【Objective】Drought and salinity are most common abiotic stresses impending crop growth, and understanding how crops hydraulically respond to these stresses is imperative for improving agronomic management. In this paper, we present the results of an experimental study on the impact of water and salinity stresses on water characteristics of maize.【Method】The experiment was conducted in a phytotron and consisted of four treatments: water stress (LD), salt stress (WS), coupled water and salt stress (SY); the control was without stress (CK). In each treatment, we measured leaf water potential, root water potential and stem hydraulic conductivity of the maize. 【Result】Compared with CK, LD, WS and SY reduced water potential in both root and leaf noticeably. In all treatments, the difference between water potential in the leaf and the soil was in the order of CK>LD>WS>SY. Water and salinity stresses both reduced initial hydraulic conductivity and sap flow rate in a similar way as their impact on the difference between water potential in the leaf and the soil; they led to an increase in the percentage of hydraulic conductivity loss of the stem xylem (PLC). Water stress reduced net photosynthetic rate, transpiration rate and stomatal conductance, and coupling water and salt stresses reduced these traits further. Plant height and leaf length in all treatments was in the order CK>LD>WS>SY.【Conclusion】Water and salt stresses in separation or in coupling both reduced water potential and imbalanced osmotic potential in the plant, thereby inhibiting photosynthesis and embolizing the stem xylem network, although the embolization varied with types and degree of the stresses. |
| Key words: water and salt stress; hydraulic conductivity; embolism; sap flow; water potential; photosynthesis |
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