中文摘要：

采用室内盆栽实验的方法,研究了UV-B辐射强度改变对冬小麦拔节孕穗期、抽穗期碳氮代谢的影响.结果表明：（1）UV-B辐射增强显著减少小麦拔节孕穗期和抽穗期地上部分干重,以及小麦拔节孕穗期地上部分呼吸速率,而对小麦两个生育期的呼吸系数无显著影响.UV-B增强显著减少了小麦拔节孕穗期和抽穗期叶片中叶绿素a含量,增加类胡萝卜素含量,减少拔节孕穗期叶片中光合产物可溶性糖的含量;（2）UV-B增强对小麦叶片中N代谢过程的影响表现为促进作用,虽对小麦抽穗期叶片硝酸还原酶活性、硝态氮含量无显著影响,却促进谷氨酰胺合成酶活性,显著增加了拔节孕穗期和抽穗期叶片中可溶性蛋白质、游离氨基酸含量.

英文摘要：

An indoor pot experiment along with laboratory analysis was done to study the influence of increased UV-B radiation on C and N metabolisms of winter wheat during elongation-pregnant and heading stages. An increase in UV-B radiation could significantly decrease the aboveground dry matter weight of winter wheat during elongation-pregnant and heading stages and the plant-mediated respiration rate in the former stage, but it induced no impact on respiration coefficient during both stages. There was less content of chlorophyll a and more arotenoid in UV-treated leaves than in the untreated ones during both stages. Also, the UV-treated leaves contained less soluble sugar during the elongation-pregnant stage. Although there was no change in nitrate contents and activities of nitrate reductase in the UV-treated leaves during heading stage, the UV treatment could increase glutamine synthetase activity in leaves significantly （P〈O.05）. Furthermore, the UV treatment increased concentrations of soluble protein and free amino acid in leaves during both stages （P〈0.1）.These results suggested that N metabolism of winter wheat could be accelerated by UV-B radiation increasing.