摘要
以先玉420为试验材料,研究在大垄双行膜下滴灌种植模式下,氮素水平对玉米穗位叶光合特征及氮代谢关键酶活性的影响。结果表明:1)玉米穗位叶氮素含量、光合速率(P n)、蒸腾速率(T r)、气孔导度(G s)、水分利用效率(WUE)、最大光化学效率(F v/F m)、实际光化学效率(ΦPSⅡ)和光化学猝灭(q P)均以N3(300 kg/hm2)水平最高。2)PEP羧化酶对氮肥的响应较RUBP羧化酶敏感,氮肥少于100 kg/hm2才显著降低RUBP羧化酶活性。3)施用氮肥均增加穗位叶硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性,以N3处理增幅最大,蛋白水解酶活性则相反。4)相关分析表明:穗位叶氮含量与与内肽酶和氨肽酶呈现负相关,与其他各项指标均呈现正相关,差异显著性因花后不同时期而不同。6)在供试试验区,在氮肥施用总量为300 kg/hm2时,玉米穗位叶保持较高的光合特性和相关酶活性,为玉米籽粒产量的形成奠定了基础。
Jilin Province is the main maize-producing province in China but frequently suffers from drought. Western parts of the province, such as Baieheng and Songyuan, do not receive sufficient rainfall to support increased agricultural production, which severely limits enhancement of maize yield. A project to install drip irrigation to one million acres was initiated in the province, which is important for improving the drought resistance and yield of maize. Nitrogen, as the most important element for maize growth, has a major impact on yield and physiological characteristics. For maize cultivated with under-mulch drip irrigation with dual lines per ridge, what influence will the nitrogen nutrition level have on photosynthesis by the ear leaf and related physiological characteristics.9 To address this question, maize Xianyu420 was used as the test material and five nitrogen nutrition levels were applied. Starting from the silking stage, on each morning at 09：00-11：00 for 10 days, six representative plants of uniform growth were selected from each treatment and the following photosynthesisparameters were measured ： ear leaf net rate of photosynthesis （Pn） , transpiration rate （ Tr） , stomatal conductance （gs） , water use efficiency （ WUE ）, maximum photochemical efficiency （ Fv/Fm ）, actual photochemical efficiency （ ФPSⅡ ）, photochemical quenching （ qp ）, nitrogen content, and the activities of phosphoenolpyruvate （ PEP ） and ribulose 1,5- biphosphate （ RUBP ） carboxylase, proteolytic enzymes （ endopeptidase and aminopeptidase）, nitrate reductase （ NR）, and glutamine synthetase （GS）. The influence of nitrogen level on photosynthesis characteristics and activity of key enzymes involved in nitrogen metabolism in the ear leaf was studied with under-mulch drip irrigation with dual lines per ridge. The results showed that the average values for ear leaf nitrogen content, Pn, Tr, gs WUE, Fv/Fm, ФPSⅡand qp were highest in the N3 treatment （300 kg N/hm2）. The response of PEP carboxylase activity to nitrogen fertilizer application was more sensitive than that of RUBP carboxylase activity. When nitrogen fertilizer application was less than 100 kg N/hm2, RUBP carboxylase activity was significantly reduced. Application of nitrogen fertilizer increased the activity of NR and GS in the ear leaf. And the highest increases in NR and GS activity were recorded in the N3 treatment. Proteolytic activity showed the opposite response. The nitrogen content of the ear leaf was negatively correlated with endopeptidase and aminopeptidase activity, and positively correlated with all other indicators of photosynthetic activity. In the study area, when the total amount of nitrogen fertilizer applied is 300 kg/hm2, the ear leaf of maize maintains higher photosynthetic parameters and relevant enzyme activity and provides the foundation for increased grain yield. Adequate supply of nitrogen fertilizer can ensure smooth and efficient activity of enzymes involved in nitrogen metabolism in leaves of maize.
出处
《生态学报》
CAS
CSCD
北大核心
2013年第23期7399-7407,共9页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目(31000687)
国家粮食丰产工程资助项目(2011BAD16B10
2012BAD04B02)
吉林省财政厅农业综合开发科技示范资助项目(松原市玉米优良新品种及大垄双行膜下滴灌技术科技示范)
吉林省科技厅科技支撑计划资助项目(20130305032NY)
吉林省现代农业产业体系资助项目(201203)
关键词
玉米
膜下滴灌
光合特性
氮素
氮代谢酶
maize
under-mulch-drip irrigation
photosynthetic characteristics
nitrogen
nitrogen metabolism enzyme
