荫蔽下大豆苗期叶片氮分配对光合氮利用效率的影响  

Effects of Leaf Nitrogen Allocation on Photosynthetic Nitrogen Use Efficiency in Shaded Soybean Seedlings

作　　者：韩肖肖 梁霞 文涛 刘卫国 HAN Xiaoxiao;LIANG Xia;WEN Tao;LIU Weiguo(College of Agriculture,Sichuan Agricultural University/Sichuan Crop Strip Intercropping Engineering and Technology Research Center,Chengdu 611130,China)

机构地区：[1]四川农业大学农学院/四川省作物带状复合种植工程技术研究中心,成都611130

出　　处：《四川农业大学学报》2024年第6期1263-1271,共9页Journal of Sichuan Agricultural University

基　　金：农业农村部科技发展中心农业生物育种重大项目(2023ZD0403405)。

摘　　要：【目的】通过了解大豆苗期叶片光合特性和氮素分配的关系,为合理配置大豆氮素营养、促进大豆光合氮利用效率和高产栽培提供理论依据。【方法】以耐荫性不同的2个大豆品种为试验材料,设置5个施氮水平处理,分析荫蔽下不同施氮处理大豆光合特性以及与氮素分配的关系。【结果】适量的氮素有利于提高荫蔽下大豆的光合速率、光合色素含量及荧光特性;施氮水平增加可显著提高2个品种的氮素分配到羧化和生物力能学系统中的氮素比例,而捕光系统中的比例差异不显著,非光合机构中氮素分配呈逐渐下降的趋势;Pn和PNUE受光合氮素分配的调控,与羧化和生物力能学系统氮素分配呈显著的正相关,与捕光系统氮素分配相关性较差。【结论】提高大豆苗期光合和氮利用效率的关键在于羧化和生物力能学系统中氮素分配,与捕光系统氮素分配关系不大;同时,耐荫性强的品种能够更好地协调光合系统中氮素的分配从而提高光合能力。【Objective】This study aims to elucidate the relationship between photosynthetic characteris‐tics and nitrogen distribution in soybean leaves at the seedling stage,thereby providing a theoretical foun‐dation for the rational allocation of nitrogen nutrition,enhancement of photosynthetic nitrogen use effi‐ciency,and the promotion of high-yield soybean cultivation.【Method】Two soybean varieties with con‐trasting shade tolerances were utilized as experimental subjects,and five nitrogen application levels were established to assess the photosynthetic characteristics of soybean under varying shade and nitrogen appli‐cation conditions,as well as their correlation with nitrogen allocation.【Result】Appropriate nitrogen ap‐plication enhanced the photosynthetic rate,pigment content,and fluorescence characteristics of soybean under shade conditions.The nitrogen distribution within the carboxylating and bioenergetic systems sig‐nificantly increased with rising nitrogen application levels,whereas the proportion of nitrogen distribu‐tion in the light harvesting systems remained unchanged,and the nitrogen allocation in non photosynthetic structures exhibited a gradual decrease.Photosynthetic nitrogen use efficiency(PNUE)and net photosynthetic rate(Pn)were positively correlated with nitrogen allocation in the carboxylating and bioenergetic systems,but showed a weak correlation with nitrogen allocation in the photoharvesting systems.【Conclusion】The key to improve the nitrogen use efficiency at seedling stage of soybean lies in nitrogen allocation in carboxylation and bioenergetics systems,and has little relationship with nitrogen allocation in light harvesting systems.At the same time,varieties with strong shade tolerance can better co‐ordinate nitrogen distribution in the photosynthetic system and improve photosynthetic capacity.

关 键 词：大豆 荫蔽 光合特性 光合氮分配 光合氮利用率 

分 类 号：S529[农业科学—作物学] S565.1