• ISSN 1008-505X
  • CN 11-3996/S
张立新, 李生秀. 长期水分胁迫下氮、钾对夏玉米叶片光合特性的影响[J]. 植物营养与肥料学报, 2009, 15(1): 82-90. DOI: 10.11674/zwyf.2009.0112
引用本文: 张立新, 李生秀. 长期水分胁迫下氮、钾对夏玉米叶片光合特性的影响[J]. 植物营养与肥料学报, 2009, 15(1): 82-90. DOI: 10.11674/zwyf.2009.0112
ZHANG Li-xin, LI Sheng-xiu. Effects of nitrogen and potassium on photosynthetic characteristics in summer maize leaves under long-term water stress[J]. Journal of Plant Nutrition and Fertilizers, 2009, 15(1): 82-90. DOI: 10.11674/zwyf.2009.0112
Citation: ZHANG Li-xin, LI Sheng-xiu. Effects of nitrogen and potassium on photosynthetic characteristics in summer maize leaves under long-term water stress[J]. Journal of Plant Nutrition and Fertilizers, 2009, 15(1): 82-90. DOI: 10.11674/zwyf.2009.0112

长期水分胁迫下氮、钾对夏玉米叶片光合特性的影响

Effects of nitrogen and potassium on photosynthetic characteristics in summer maize leaves under long-term water stress

  • 摘要: 采用2 种不同夏玉米基因型(陕单9号,抗旱品种;陕单911,不抗旱品种)的盆栽试验,研究了长期水分胁迫下氮、钾对各生育期叶片净光合速率、蒸腾速率、胞间二氧化碳浓度和叶绿素含量的影响,旨在从光合生理特性揭示这些因子的抗旱机理。结果表明,长期水分胁迫下叶片净光合速率、蒸腾速率、胞间二氧化碳浓度(除成熟期)和叶绿素含量显著降低,不抗旱品种降幅更甚。抗旱品种的净光合速率和叶绿素含量大于不抗旱品种,而蒸腾速率和胞间二氧化碳浓度则相反。两品种苗期光合作用较弱,净光合速率和叶绿素含量均较低,抽雄期达到高峰。施氮能不同程度降低水分胁迫下玉米叶片的蒸腾速率,增加叶绿素含量,提高净光合速率,从而减缓水分胁迫对光合作用的伤害。随氮肥用量增加,不抗旱品种净光合速率和叶绿素含量显著升高,蒸腾速率和胞间二氧化碳浓度明显降低,两种氮肥用量间有显著差异;抗旱品种在低氮用量时效果显著,但高低氮用量间无显著区别。钾对受水分胁迫的玉米表现出比氮肥更突出的效果。相反,在适量供水条件下,氮钾肥的作用明显下降。以上结果表明,适当用量的氮、钾肥,可以有效地改善水分胁迫下作物叶片的光合特性,从而增强作物的抗旱性。

     

    Abstract: Two cultivars of summer maize (Zea mays L.) with known drought-resistance rankings (Shaandan 9 more tolerant than Shaandan 911) were subjected to progressive soil water stress in pot throughout their growth period to investigate effects of nitrogen and potassium on net photosynthetic rate (Pn), intercellular CO2 concentration (Ci) and transpiration rate (Tr) in maize leaves at different growing stages for revealing their biological function in increase of plant resistance to drought in view of photosynthetic metabolism. Results showed that under a long-term water stress condition, net photosynthetic rate (Pn), Intercellular CO2 concentration (Ci) (except mature stage) and transpiration rate (Tr) in leaves were significantly decreased as well as chlorophyll content for both the drought resistant and non-drought resistant varieties. And the decline rates of them were more obvious for the non-drought resistant variety than the drought resistant one. Moreover, the chlorophyll content and Pn were higher while Tr and Ci lower for the drought resistant variety compared with the drought sensitive one .The lower Pn and chlorophyll content were recorded at seedling stage than those at elongation and heading stages, which showed that the two varieties responses to water stress were weaker at earlier than later stages. Their peak values occurred at heading stage. Application of nitrogen raised Pn and chlorophyll content whereas decreased Tr and Ci at different extent and thus alleviated the detrimental effects of water stress on photosynthesis of plants. Under the water-stressed condition, addition of N fertilizer significantly increased Pn and chlorophyll content while decreased Tr and Ci for the non-drought resistant variety. And a significant difference of them was obtained among N rates. The significant response of drought resistant variety to N addition was merely found at low N rate and there was no significant difference between high and low N rates. K exhibited more significant biological function than N in improvement of photosynthesis at the same level water stress. However, with adequate water supply, effects of N and K fertilization were significantly decreased. All the results indicated that addition of optimal nitrogen and potassium had made an efficient contribution to enhancing drought-resistance ability of a crop by improvement of its photosynthetic traits.

     

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