›› 2008, Vol. 16 ›› Issue (1): 11-16.DOI: 10.11733/j.issn.1007-0435.2008.01.003

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Hydraulic Lift in Plant Root System and Soil Water Potential Study on Mechanism of Hydraulic Lift in Root System of Alfalfa and Maize Ⅲ

LI Wei1, HU Zi-zhi2, WAN Chang-gui3, LI Sheng1, SUN Xu-wu4   

  1. 1. College of Life Science and Technology, Gansu Agriculture University, Lanzhou, Gansu, 730070, China;
    2. Pratacultural College, Gansu Agriculture University, Lanzhou, Gansu, 730070, China;
    3. Department of Range, Wildlife and Fisheries, Texas Tech University, Lubbock, TX, 79409, USA;
    4. College of Life Science, Lanzhou University, Lanzhou, 730000, China
  • Received:2007-01-25 Revised:2007-07-17 Online:2008-02-15 Published:2008-02-15

苜蓿、玉米根系提水作用与土壤水势—-植物根系提水作用机理研究3

李唯1, 胡自治2, 万长贵3, 李胜1, 孙旭武4   

  1. 1. 甘肃农业大学生命科学技术学院, 兰州, 730070;
    2. 甘肃农业大学草业学院, 兰州, 730070;
    3. 美国德克萨斯技术大学, 德克萨斯州, TX79409, 美国;
    4. 兰州大学生命科学学院, 兰州, 730000
  • 作者简介:李唯(1955- ),男,甘肃省成县人,教授,主要从事作物生态生理研究,E-mail:liwei@gsau.edu.cn
  • 基金资助:
    甘肃省人事厅“333创新人才工程”专项资助(035-036080)

Abstract: The hydraulic lift by root system at night was investigated on 1-year old alfalfa,a high-yield maize variety Zhongdan No.2,and a drought-resistant maize variety Yuyu No.22.The water potential difference between the shallow and deep soil was measured with neutron probe 503 DR.The results indicate that the water potential of the top soil was between-0.640 to-1.520 MPa for 1-year old alfalfa,-0.359 to-1.327 MPa for Zhongdan No.2,and-0.502 to-1.429 MPa for Yuyu No.22,respectively;Yuyu No.22 was lower than Zhongdan No.2 and higher than alfalfa.The average water potential difference between the shallow and deep soil was 0.620 MPa for 1-year old alfalfa,0.431 MPa for Zhongdan No.2,and 0.531 MPa for Yuyu No.22;Yuyu No.22 was higher than alfalfa and lower than Zhongdan No.2.The hydraulic lift capacity was enhanced by lower water potential in the shallow soil and larger water potential difference between the shallow and deep soil layers.At such soil conditions,plant has stronger water keep capacity in its root cells and relative weaker hydraulic lift.

Key words: Hydraulic lift in root system, Water potential, Water potential difference, Drought-resistance

摘要: 为揭示植物根系提水作用发生的机制,利用503DR型中子水分仪对1龄苜蓿、中单2号和豫玉22号玉米夜间发生根系提水作用时浅、深层土壤水势进行成对测定分析。结果显示:1龄苜蓿夜间总根系提水作用发生时的浅层土壤水势在-0.640-1.520 MPa,中单2号在-0.359-1.327 MPa,而豫玉22号玉米则在-0.502-1.429 MPa,其高低顺序为:中单2号>豫玉22号>1龄苜蓿;出现根系提水作用时的浅、深层土壤水势差,1龄苜蓿平均为0.620 MPa,中单2号和豫玉22号玉米分别平均为0.431和0.531 MPa,其高低顺序为1龄苜蓿>豫玉22号>中单2号;较低的浅层土壤水势和较大的浅、深层土壤水势差促进植物根系的提水作用。但在较低的浅层土壤水势和较大的浅、深层土壤水势差情况下才出现根系提水作用的植物,其根细胞具有较强的保水能力和相对较小的根系提水作用。

关键词: 根系提水作用, 水势, 水势差, 抗旱性

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