骆驼刺叶片化学计量特征和非结构性碳水化合物对水氮添加的响应OA

Objective:Water and nitrogen are the main limiting factors for the growth of desert plants.This study aims to explore the regulatory mechanism of water-nitrogen coupling on the nutrient utilization strategy and carbon metabolism ofAlhagi sparsifolia seedlings,so as to provide a theoretical basis for desert vegetation restoration and wa-ter-fertilizer management.Method:Taking Alhagi sparsifolia seedlings as experimental materials,a completely randomized block pot experiment with 2 water levels and 3 nitrogen levels was set up.The response rules of leaf carbon(C),ni-trogen(N),phosphorus(P)stoichiometric characteristics and non-structural carbohydrates(NSCs)were determined and analyzed.Result:Under mild drought stress,the medium nitrogen treatment significantly increased the contents of C,N and P in leaves,promoting nutrient accumulation and stress resistance improvement;the low nitrogen treatment promot-ed the accumulation of NSCs(especially starch)under both water conditions,while the medium nitrogen treatment tend-ed to lead to excessive consumption of NSCs;leaf N content was significantly negatively correlated with soluble sugar content and SS:ST ratio,and leaf P content was significantly negatively correlated with NSCs.Conclusion:Nitrogen and phosphorus metabolism is closely related to carbohydrate distribution.Alhagi sparsifolia adapts to the water-nitrogen coupling environment by flexibly adjusting leaf stoichiometry and NSCs accumulation and distribution.This study clari-fies its resource allocation strategy and provides support for precise regulation of water and fertilizer in deserts.