大气CO_2浓度和供氮水平对油菜前期生长及氮素吸收利用的影响  

Effects of atmospheric CO_2 concentrations and N application levels on the growth,N uptake and utilization of oilseed rape during vegetative stage

作　　者：王小娟[1,2] 王文明[1] 张振华[1] 张力[1] 杨春[1] 宋海星[1] 官春云[3] 

机构地区：[1]湖南农业大学资源环境学院,土壤肥料资源高效利用国家工程实验室,农田污染控制与农业资源利用湖南省重点实验室,植物营养湖南省普通高等学校重点实验室,长沙410128 [2]海南省农业科学院,海口571100 [3]国家油料改良中心湖南分中心,长沙410128

出　　处：《生态学杂志》2014年第1期83-88,共6页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(31071851和31101596);湖南省高校创新平台开放基金项目(09K049);湖南省高校创新平台开放基金项目(12K064和10K034);国家油菜产业技术体系栽培生理岗位;国家支撑计划项目(2012BAD15B04和2010BAD01B01);湖南省政府专项资助

摘　　要：采用砂培试验,在2种CO2浓度(自然CO2浓度400μmol·mol-1和高CO2浓度700μmol·mol-1)和2种供氮水平(常氮15 mmol N·L-1和氮胁迫5 mmol N·L-1)下,研究了油菜营养生长阶段的干物质累积和氮素吸收利用的变化。结果表明:高CO2浓度条件下,油菜株高、根茎粗和干物质累积量增加,其中,常氮条件下,根茎粗和地上部干重的增加幅度大于氮胁迫条件,株高和根系干重增加幅度则常氮条件小于氮胁迫条件;高CO2浓度下,根体积、根系活跃吸收面积和总吸收面积在2个供氮水平下均增加,而一级侧根数只在常氮条件下增加,根长只在氮胁迫条件下增加;高CO2浓度条件下,油菜各器官含氮量下降,其中,叶片和根系的含氮素量下降幅度明显大于茎;高CO2浓度条件下,正常供氮时根、茎、叶氮素累积量均增加,氮胁迫时茎氮素累积量增加,而根和叶的氮素累积量减少;高CO2浓度条件下,氮素吸收效率、氮素利用效率和氮效率均增加,常氮条件下增加幅度大于低氮条件,其中,氮素利用效率对氮水平的响应更加明显。Dry biomass and changes of nitrogen （N） uptake and utilization in oilseed rape during vegetative growth stage at two levels of CO2 （natural： 400 μmol·mol-1, elevated： 700 μmol·mol-1） and two levels of N application （normal： 15 mmol·L-1, limited： 5 mmol·L-1） were studied in a sand culture experiment. Results showed that plant height, basal diameter and dry biomass were increased under the elevated CO2 concentration, and the increment of either basal diameter or dry biomass at the normal N level was higher than that at the limited N level, but the increased degree of plant height and root dry weight showed an opposite pattern. Regardless of the N application levels, root volume, total active absorption area were increased under the elevated CO2 concentration, but number of the first lateral root was only increased at the normal N level, root length was only increased at the limited N level. N content in organs of oilseed rape was declined under the elevated CO2 concentration, and the declined degree of N contents in leaves and roots was significantly higher than that of stems. Under the elevated CO2 concentration, accumulation amount of N in roots, stems and leaves were increased at the normal N level, only increased in stems at the limited N level, and decreased in roots and leaves. N uptake efficiency, N use efficiency （NUE） and N efficiency were increased under the elevated CO2 concentration, and increased degree at the normal N level was higher than at the limited N level, and the response of NUE to N application levels was more obvious.

关 键 词：干物质累积 根系特性 氮素吸收累积 油菜 

分 类 号：S565.4[农业科学—作物学]