摘要
Abstract
In order to study the best effect of nitrogen on growth, yield and quality of wheat, five nitrogen levels were set at 0, 105, 175, 245 and 315 kg·hm-2 in Zhoumai 22. The photosynthetic characteristics, chlorophyll content (SPAD value), correlation between nitrogen application and SPAD value, carbon and nitrogen substitution of wheat flag leaves were studied. Effects of enzyme activity, grain yield and protein content were investigated. The results showed that the photosynthetic characteristics, SPAD value, carbon and nitrogen metabolism related enzymes activities, grain yield and protein content of wheat were significantly affected by different nitrogen levels. In the range of 0 ～245 kg·hm-2, the photosynthetic rate and SPAD value increased with the increase of nitrogen dosage, reached the maximum at 245 kg·hm-2, increased by 142.51％ and 3.05％ respectively compared with the control, and the difference was very significant (P<0.01) ; the above indexes decreased at 315 kg·hm-2. The variation of transpiration rate and stomatal conductance were consistent. The maximum value was at N175, which was 165.91％ and 89.16％ higher than that of the control. There was a negative correlation between intercellular CO2 concentration and photosynthetic rate. SPAD value at jointing stage had a significant positive correlation with the amount of nitrogen used, the determination coefficient was 0.816, and the correlation coefficient was0.783. Grain yield and sucrose phosphate synthetase activity showed a single peak change law with the increase of nitrogen application, the maximum value was at 245 kg·hm-2, 28.19％ and 31.71％ higher than the control, respectively, and the difference was very significant (P<0.01) ; grain protein content and nitrate reductase content changed similarly, both enhanced with the increase of nitrogen content, the maximum value was at 315 kg·hm-2. However, according to the comprehensive indexes of photosynthetic rate, SPAD value, yield and quality, 245 kg·hm-2 was used as the optimum nitrogen fertilizer for Zhoumai 22 in eastern Henan Province.关键词
氮素/光合特性/SPAD值/产量/碳氮代谢Key words
nitrogen/photosynthetic characteristics/SPAD value/yield/carbon and nitrogen metabolism分类
农业科技
