《植物生理学报》 2009, 45(1): 13-18

抗旱性不同品种的小麦叶片中光合电子传递和分配对氮素水平的响应

张绪成^1,2,*, 上官周平²

1 甘肃省农业科学院旱地农业研究所, 农业部西北作物抗旱栽培与耕作重点开放实验室, 兰州 730070; 2 中国科学院水土保持研究所, 黄土高原土壤侵蚀与旱地农业国家重点实验室, 陕西杨陵 712100

通信作者：张绪成；E-mail: gszhangxuch@163.com；Tel: 0931-7612800

摘　要：

在大田控制条件下, 以植物叶片气体交换和叶绿素荧光测定相结合的方法, 研究抗旱性不同品种冬小麦拔节期叶片 的光合电子传递及激发能利用分配对氮素响应的结果表明, 施氮可提高抗旱性不同品种小麦叶片天线色素吸收光能的能力, 虽然氮素不能改变激发能在光合碳还原(PCR)和光合碳氧化(PCO)之间的分配比例, 但可提高PSII总电子传递速率(JF)和Pn。 低氮下不同品种小麦叶片的热耗散比例有差异, 但中高氮下叶片之间无显著差异。旱地品种的JF值随氮素水平的提高而先 增加后下降, 而水地品种则表现为持续升高; 2 个小麦品种的叶片J0 值随氮素水平的提高而呈持续升高的变化趋势。氮素 对叶片PSII反应中心活性有影响, 而不同抗旱性品种之间亦有差别, 说明施氮可改善小麦叶片热耗散和光化学反应对激发 能的竞争关系, 从而增强光合机构的自我保护能力。

关键词：氮素; 抗旱性; 光合电子传递; 光能分配; 小麦

收稿：2008-09-05   修定：2008-11-24

资助：黄土高原土壤侵蚀与旱地农业国家重点实验室开放基金(10501-174)和甘肃省中青年科技基金(3YS061-A25-015)。

Responses of Photosynthetic Electron Transport and Partition in the Winter Wheat Leaves of Different Drought Resistances to Nitrogen Levels

ZHANG Xu-Cheng^1,2,*, SHANGGUAN Zhou-Ping²

¹Key Laboratory of Northwest Crop Drought-resistant Farming, Ministry of Agriculture, Institute of Dryland Agriculture, Gansu Academy of Agriculture Sciences, Lanzhou 730070, China; ²State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling, Shaanxi 712100, China

Corresponding author: ZHANG Xu-Cheng; E-mail: gszhangxuch@163.com; Tel: 0931-7612800

Abstract:

The responses of photosynthetic electron transport and excitation energy distribution in winter wheat leaves at the jointing stage to nitrogen levels were studied in the field experiment, both leaf gas exchange parameter and chlorophyll fluorescence were measured. The light energy absorbed by antenna pigment of both cultivars increased with the treatment of nitrogen. Although nitrogen could not obviously change the distribution proportion of photosynthetic carbon reduction and photosynthetic carbon oxidation, nitrogen could increase J_F of PSII and photosynthetic rate. The heat dissipation proportion in different winter wheat cultivar leaves was significantly different under low nitrogen condition. But there were no obvious differences in leaves under middle or high nitrogen condition. J_F of dryland cultivar increased with the increasing levels of nitrogen at first and then decreased, while J_F of watered cultivar increased continuously with the increasing levels of nitrogen. J₀ of the two cultivars also increased continuously with the increasing levels of nitrogen. Nitrogen could affect PSII activities of both cultivars, and there were significant differences between the two cultivars. Nitrogen application improved the competition between heat dissipation and photo-chemic reaction and enhanced the self-protection ability of photosynthetic apparatus.

Key words: nitrogen; drought resistance; photosynthetic electron transport; light energy distribution; wheat