不同水、氮条件对水稻苗生长及伤流液的影响  

Effects of water and nitrogen forms on growth and xylem sap of rice seedlings

作　　者：柏彦超[1] 钱晓晴[1] 沈淮东[1] 薛巧云[1] 王娟娟 陈峰[1] 汪孙军[1] 

机构地区：[1]扬州大学环境科学与工程学院,江苏扬州225009 [2]莱顿大学数学与自然科学系,荷兰莱顿2300RA

出　　处：《植物营养与肥料学报》2009年第1期76-81,共6页Journal of Plant Nutrition and Fertilizers

基　　金：国家自然科学基金项目(30370816);江苏省自然科学基金项目(BK2002049)资助。

摘　　要：为探明不同水分供应和氮素形态对水稻根苗及伤流液的影响,没正常水分及50 g/L PEG模拟水分胁迫和3种不同质量比例的NH_4^+-N/NO_3^--N(9/1、5/5、1/9)氮素营养处理,测定了水稻幼苗生物量,根系形态指标,根系活力及根基伤流量。结果表明,正常水分条件下,NH_4^+-N促进水稻根系平均直径增大,有利于水稻地上部物质累积;NO_3^--N则使水稻根系总吸收面积增大,促进根系物质累积;NH_4^+-N/NO_3^--N为5/5处理的水稻活跃吸收面积最大,活跃吸收面积比亦最高。水分胁迫条件下,NH_4^+-N/NO_3^--N为5/5的处理更有利于水稻地上部分的生长,NO_3^--N有利于水稻鲜重和干重增加,促进根系平均直径增大,水稻的根系总吸收面积、活跃吸收面积均随NO_3^--N供应比例的增加呈上升趋势。正常水分条件下,水稻幼苗白天的耗水量随NH_4^+-N/NO_3^--N比例降低呈下降趋势,水分胁迫条件降低了水稻对水分的吸收。水分胁迫显著降低各处理水稻伤流量,正常水分条件下,NH_4^+-N/NO_3^--N为5/5处理的水稻伤流量最大;水分胁迫后,9/1处理的水稻伤流量相对较多。To study the effects of different water and nitrogen supply on the growth and xylem sap conditions on rice seedlings, experiments were designed under two water stress conditions, non-water stress and assimilated 50 g/L PEG water stress. Different nitrogen treatments were also designed by using various combination rate of ammonium and nitrate, with NH4^＋-N/NO3^--N ratio of 9/1, 5/5 and 1/9. Total biomass, root morphological index, root activity and the amount of xylem sap excaudate were measured. Results showed that under non-water stress conditions, NH4^＋-N supply increased the average diameter of rice roots and accumulation of shoot biomass, while NO3^--N increased total root absorption area and biomass accumulation in roots. The highest active absorption area and the highest percentage of active absorption area were reached when samples were treated with NH4^＋ -N/NO3^--N at a ratio of 5/5. Under water stress conditions, nitrogen ratio at 5/5 was the best for rice shoot growth, while NO^3--N was beneficial to both fresh and dry weight of rice and average root diameter. Total and active root absorption area also increased with the increase of NO^3--N. In non-water stress treatments, daytime water consumption dropped with the decreased ratio of NH4^＋ -N/NO^3--N. Water stress treatment significantly reduced the water uptake of rice. The amount of xylem sap was negatively influenced by water stress treatments Highest amount of root xylem sap was found when seedlings were treated with 5/5 NH4^＋ -N/NO3^--N without water stress, and with 9/1 NH4^＋ -N/NO3^--N under water stress conditions.

关 键 词：水稻 水分胁迫 氮素 伤流液 

分 类 号：S511[农业科学—作物学]