| 摘要: |
| 为研究不同形态氮素(NH4+-N和NO3--N)和水分胁迫互作时水稻渗透调节的差异，利用营养液培养，通过PEG(6000)对局部根系进行水分胁迫，分析比较水稻各部位主要渗透调节物质含量的变化。结果表明：局部根系水分胁迫时，供NH4+-N时受胁迫一侧根系生长无明显变化，根系可溶性糖和游离氨基酸含量分别增加64.5%和167%，根系木质部和韧皮部汁液中的可溶性糖含量分别增加243%和42.2%；而供NO3--N时受胁迫一侧根系韧皮部汁液中可溶性糖含量显著降低，根系生长受到明显抑制，尽管可溶性糖和游离氨基酸含量分别增加46.4%和73.9%，韧皮部汁液中可溶性糖含量显著降低。未受胁迫一侧根系生物量累积则明显增大，这与其韧皮部汁液中的可溶性糖含量明显升高相一致。NH4+-N营养使水稻通过渗透调节有效抵抗水分胁迫，是典型的“耐旱”类型；而供应NO3--N营养时渗透调节并未发挥明显作用，而采用典型的“避旱”类型，无法避旱时水稻生长则受到抑制。 |
| 关键词: 水稻 水分胁迫 分根 不同形态氮素 可溶性糖 游离氨基酸 |
| DOI：10.11841/j.issn.1007-4333.2014.05.06 |
| 投稿时间：2014-01-03 |
| 基金项目:浙江省环保科技计划项目（2012B016）；嘉兴市科技计划项目（2011AY1047，2012AY1055） |
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| Effect of N nutrition and water stress on riceosm oregulation at seedling stage |
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CHEN Gui1, GUO Shi-wei2, ZHAO Guo-hua3, ZHANG Hong-mei1, SHEN Ya-qiang1, CHENG Wang-da1
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| (1.Development of Agricultural Ecological Environment, Jiaxing Academy of Agricultural Science, Jiaxing 314016, China;2.College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China;3.College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, China) |
| Abstract: |
| To study different mechanism of osmoregulation of rice under water stress and supplied with NH4+-N and NO3--N, a hydroponic experiment of partial root under water stress simulated by PEG (6000) was conducted to analyze and compare concentration changes of main osmo-regulation substances.The result showed growth of rice partial root under water stress was not significantly affected when supplied NH4+-N.The concentrations of soluble sugar and free amino acid in partial root under water stress were increased by 64.5% and 167%.In addition, the soluble sugar concentrations in xylem sap and phloem sap were 243% and 42.2% higher than partial root under normal water level.However, partial root under water stress was obviously suppressed when supplied NO3--N nutrition.Although, the concentrations of soluble sugar and free amino acid were 46.4% and 73.9% higher than partial root without water stress.The soluble sugar concentration in phloem sap was found to decrease significantly.However, biomass of partial root without water stress was obviously larger than any partial root under normal water level supplied with NO3--N, which was in line with its markedly higher soluble sugar in phloem sap.In conclusion, rice could successfully resist water stress through osmoregulation with NH4+-N nutrition supply.This could be called "drought endure"type.However, when supplied NO3--N nutrition, rice chose to avoid water stress after failed osmoregulation, which was called "drought escape"type.Rice growth would be obviously restrained when no way was possible to escape water stress. |
| Key words: rice water stress split root various nitrogen forms soluble sugar free amino acid |
