植物生态学报 ›› 2008, Vol. 32 ›› Issue (5): 1194-1200.DOI: 10.3773/j.issn.1005-264x.2008.05.024

• 研究论文 • 上一篇    下一篇

返青期根修剪对冬小麦后期耐旱性及水分利用效率的影响

马守臣1,2, 李凤民2,3,*(), 徐炳成2, 黄占斌4   

  1. 1 河南理工大学测绘与国土信息工程学院,河南焦作 454000
    2 中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实 验室,陕西杨凌 712100
    3 兰州大学干旱与草地生态教育部重点实验室,兰州 730000
    4 中国矿业大学环境与化学工程学院,北京 100083
  • 收稿日期:2007-10-08 接受日期:2008-05-17 出版日期:2008-10-08 发布日期:2008-09-30
  • 通讯作者: 李凤民
  • 作者简介:*(fmli@lzu.edu.cn)
  • 基金资助:
    国家自然科学基金(30625025);中国科学院“百人计划”项目(C24016200);河南理工大学博士基金(B2008-30);中国科学院“西部之光”人才培养计划(2006YB01)

EFFECTS OF ROOT PRUNING AT THE REGREENING STAGE ON DROUGHT TOLERANCE AND WATER USE EFFICIENCY OF WINTER WHEAT IN LATE GROWING STAGE

MA Shou-Chen1,2, LI Feng-Min2,3,*(), XU Bing-Cheng2, HUANG Zhan-Bin4   

  1. 1School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo, Henan 454000, China
    2State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100, China
    3Key Laboratory of Arid and Grassland Ecology, Ministry of Education, Lanzhou University, Lanzhou 730000, China
    4School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083, China
  • Received:2007-10-08 Accepted:2008-05-17 Online:2008-10-08 Published:2008-09-30
  • Contact: LI Feng-Min

摘要:

通过盆栽试验研究了返青期根修剪对冬小麦(Triticum aestivum)后期耐旱性及水分利用效率的影响。在返青期设置了两个根修剪处理: 1)小剪根, 在植株一侧切去部分侧生根; 2)大剪根, 在主茎四周切去部分侧生根。不剪根者设为对照(CK)。研究结果显示, 两个根修剪处理均显著减少了小麦的根系, 但对根冠比没有显著影响。在花期, 两个根修剪处理的小麦旗叶的叶绿素荧光参数最大光化学效率(The maximum photochemical efficiency of PSⅡ,Fv/Fm)、 PSⅡ潜在活性 (PSⅡ potential activity,Fv/Fo)、实际光化学量子产量(Effective PSⅡ quantum yield,ΦPSⅡ)、表观光合电子传递速率(Apparent rate of photosynthetic electron transport, ETR)、光化学淬灭系数( Coefficient of photochemical quenching, qP)和非光化学淬灭系数(Coefficient of non-photochemical quenching,NPQ)值, 在停止供水7 d后, 均显著高于对照, 这表明根修剪小麦的耐旱性强于对照, 因此在干旱胁迫下有较高的光化学活性。小剪根处理在高水条件下对小麦产量无显著影响, 而在中度干旱条件下显著提高了小麦的产量, 因此, 小剪根处理显著提高了小麦的抗旱系数; 小剪根处理在高水分处理(土壤水分含量为田间持水量的85%)和中度干旱胁迫处理(土壤水分含量为田间持水量的55%)条件下, 均显著提高了小麦的水分利用效率。但大剪根处理由于严重影响了群体数量和产量, 水分利用效率和抗旱系数均没有提高。可见, 适当地减少根系有助于小麦的耐旱性和水分利用效率的提高。

关键词: 冬小麦, 根修剪, 耐旱性, 水分利用效率

Abstract:

Aims Water use efficiency (WUE) and drought tolerance of crops are important in arid and semiarid areas. Our objective was to investigate the effects of root pruning at the regreening stage on drought tolerance and WUE of winter wheat (Triticum aestivum) in late growing stage.

Methods We manipulated root size by root pruning regreening plants grown in pots. In a light root pruning treatment, we partially cut off the secondary lateral roots along one side of the plant. In a heavy root pruning treatment, we partially cut off the secondary lateral roots along four sides of the plant. Control plants (CK) were left intact.

Important findings Both the root pruning treatments reduced the root system significantly, but their root/shoot ratio remained similar. The values of chlorophyll fluorescence parameters, i.e., the maximum photochemical efficiency of PSⅡ (Fv/Fm), PSⅡ potential activity (Fv/Fo), effective PSⅡ quantum yield (ΦPSⅡ), apparent rate of photosynthetic electron transport (ETR), coefficient of photochemical quenching (qP) and coefficient of non-photochemical quenching (NPQ), were significantly higher in both treatments than the control 8 days after withholding water at anthesis. This means that root pruning improved drought tolerance of wheat, resulting in improved photosynthetic capability. Light root pruning had no significant effects on grain yield under wet condition, but improved yield under moderate drought stress. Therefore, light root pruning wheat produced a higher index of drought resistance compared with the control. Light root pruning improved WUEof wheat under two water conditions. Heavy root pruning did not improve WUE or the index of drought resistance due to a reduced shoot density and grain yield. The study showed that reducing root size moderately through breeding or agricultural measures would be beneficial to improving drought tolerance and WUEin winter wheat.

Key words: winter wheat, root pruning, drought tolerance, water use efficiency