施氮和高温胁迫对杜鹃幼苗根系构型和生理指标的影响  

Effects of nitrogen application and high⁃temperature stress on root configuration and physiological indices of rhododendron seedlings

作　　者：曾鸣谦 吴丽君[1] 周围[1] 赵二毛 曹受金[1] ZENG Mingqian;WU Lijun;ZHOU Wei;ZHAO Ermao;CAO Shoujin(Central South University of Forestry and Technology,Changsha 410004,China;Bureau of Agriculture and Rural Affairs of Lilin,Lilin 412200,Hunan,China)

机构地区：[1]中南林业科技大学,长沙410004 [2]湖南省醴陵市农业农村局,湖南醴陵412200

出　　处：《生态学杂志》2025年第2期451-459,共9页Chinese Journal of Ecology

基　　金：湖南省林业厅科技创新项目(XLK201830);湖南省教育厅优秀青年项目(22B0253)资助。

摘　　要：以‘五彩夏鹃’为实验材料,研究了施氮(0、0.46和0.92 g N·株^(-1))对高温胁迫(26℃/22℃、34℃/30℃和38℃/34℃)下植株的缓解作用,旨在为提高植物抗逆性、适应气候变化提供科学依据。结果表明:在高温胁迫下,幼苗根系构型趋向叉状分枝。在26℃/22℃条件下,0.46 g N·株^(-1)氮处理显著增加了根系分叉,而0和0.92 g N·株^(-1)处理均导致根系分叉显著减少。在相同水平氮素处理下,34℃/30℃和38℃/34℃条件下植株叶面积、总根长、根表面积、比根长、比表面积和根冠比显著降低,而根系拓扑系数、可溶性蛋白含量和游离氨基酸含量显著上升。低氮处理(0.46 g N·株^(-1))显著提高了高温胁迫下植株的叶面积、比根长、根冠比、可溶性蛋白含量和游离氨基酸含量,而高氮处理(0.92 g N·株^(-1))导致叶面积、比根长、根冠比显著下降,可溶性蛋白含量和游离氨基酸含量显著上升。主成分分析和隶属函数分析结果显示,幼苗综合表现最佳的3个处理是T3(26℃/22℃、0.92 g N·株^(-1))、T2(26℃/22℃、0.46 g N·株^(-1))和T5(34℃/30℃、0.46 g N·株^(-1)),综合得分分别为0.853、0.559和0.550,其幼苗的综合表现均优于对照处理T1(26℃/22℃、0 g N·株^(-1))。总体而言,高温胁迫限制了‘五彩夏鹃’幼苗的根系生长,降低了其可溶性蛋白含量,而适量的氮素施用(0.46 g N·株^(-1))能够缓解高温对根系生长的抑制,提高植株对高温的抗性和适应性。本研究结果为杜鹃栽培中提前采取施肥措施以规避夏季高温热害、促进杜鹃优良品种在园林中的应用提供了参考依据。We investigated the alleviating effects of nitrogen(N)application(0,0.46 and 0.92 g per plant)on Rhododendron‘Wucai’ng’under different high temperature stresses(26℃/22℃,34℃/30℃and 38℃/34℃),aiming to provide a scientific basis for enhancing plant stress resistance and adaptation to climate change.The results showed that there was a trend of fork⁃shaped branch structure formed in the roots of seedlings under high temperature stress.At 26℃/22℃,there was a significant increase in root bifurcation in the N fertilizer treatment of 0.46 g per plant,but a significant decrease in the N fertilizer treatments of 0 and 0.92 g per plant.Under the same level of N fertilizer,there were significant decreases in leaf area,total root length,root surface area,specific root length,specific surface area,and root⁃shoot ratio,but significant increases in root topology coefficient,soluble protein content,and free amino acid content in plants at 34℃/30℃and 38℃/34℃,compared to that at 26℃/22℃.There were significant increases in leaf area,specific root length,root⁃shoot ratio,soluble protein content and free amino acid content of plants under high temperature stress in low N fertilizer treatment(0.46 g·plant^(-1)),while there were significant decrease in leaf area,specific root length,root⁃shoot ratio,except for a significant increase in soluble protein content and free amino acids,in the high N fertilizer treatment(0.92 g·plant^(-1)).The results of principal component analysis and membership function analysis showed that the best performance of seedlings was recorded in the treatments of T3(26℃/22℃and 0.92 g·plant^(-1)),T2(26℃/22℃and 0.46 g·plant^(-1))and T5(34℃/30℃and 0.46 g·plant^(-1)),with a score of 0.853,0.599 and 0.550,respectively,exhibiting better overall performance than that in the T1 control treatment(26℃/22℃and 0 g·plant^(-1)).In con⁃clusion,high temperature stress would restrict root growth of seedlings and reduced soluble protein content.Appro⁃priate applica

关 键 词：杜鹃 氮素施肥 夏季高温热害 根系生长 生理特性 

分 类 号：S685.21[农业科学—观赏园艺]