北京典型绿化树种幼苗对干旱-复水的光合生理响应  

Photosynthetic physiological responses of seedlings of two typical tree species in Beijing to drought stress and rehydration

作　　者：赵娜 刘诗莹 李少宁[1,3] 徐晓天 温佳美 鲁绍伟 ZHAO Na;LIU Shiying;LI Shaoning;XU Xiaotian;WEN Jiamei;LU Shaowei(Institute of Forestry and Pomology,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100093,China;Beijing Yanshan Forest Ecosystem Positioning Observation and Research Station,Beijing 100093,China;College of Forestry,Shenyang Agricultural University,Shenyang,Liaoning 110866,China)

机构地区：[1]北京市农林科学院林业果树研究所,北京100093 [2]北京燕山森林生态系统定位观测研究站,北京100093 [3]沈阳农业大学林学院,辽宁沈阳110866

出　　处：《森林与环境学报》2022年第4期374-383,共10页Journal of Forest and Environment

基　　金：国家自然科学基金项目“北京山区典型植被幼苗非结构性碳水化合物存储机制研究”(31800363);“基于模拟试验的北京园林绿化树种对PM 2.5吸滞与分配机制研究”(32071834);北京市农林科学院科技创新能力建设资助项目“北京主要林木树种种质创新与生态功能提升”(KJCX20200207);“农林复合体系模式研究与示范”(KJCX20200801)、“顺义基地林果花卉资源筛选及栽培技术示范”(KJCX20200602)。

摘　　要：为探讨北京地区典型绿化树种刺槐(Robinia pseudoacacia)和油松(Pinus tabuliformis)幼苗对干旱胁迫的光合生理响应与环境适应性机制。通过监测、调控盆栽土壤体积含水量,模拟生长季初期干旱及旱后复水事件,结果发现:土壤逐渐干旱过程中,刺槐盆栽幼苗光合参数均显著低于水分充足条件的刺槐幼苗(对照组,CK)(P<0.05),其中干旱处理下刺槐净光合速率(P_(n))、蒸腾速率(T_(r))和气孔导度(G_(s))较CK降幅90%以上,而油松幼苗各光合参数无显著变化。在干旱过程中,刺槐幼苗光合能力受气孔与非气孔限制影响,而油松幼苗则主要受气孔限制作用。经历旱后复水,刺槐幼苗P_(n)恢复至CK水平的时间(第9天)晚于油松(第6天)。两树种幼苗光合参数均出现复水超补偿效应。两种幼苗光合生理参数对干旱持续时间(D_(n))及复水持续时间(W_(n))响应程度有所不同。刺槐幼苗P_(n)、G_(s)和T_(r)随D_(n)增加逐渐减小(P<0.05),其W_(n)与G_(s)和T_(r)(P<0.05)呈显著正相关;油松幼苗经历干旱、复水的持续时间与其光合参数无显著相关。不同树种幼苗光合生理参数与其干旱-复水特定时段内的持续时间呈显著相关(P<0.05)。刺槐和油松幼苗采用不同的水分利用效率(E_(wu))策略应对土壤水分条件的剧烈变化。干旱前、中期刺槐幼苗E_(wu)升幅(51.5%)小于油松幼苗(70.2%),而刺槐E_(wu)复水后出现超补偿效应的速度(第6天)快于油松(第14天)。Two typical greening tree species in Beijing,Robinia pseudoacacia and Pinus tabulaeformis,were selected for investigating their photosynthetic physiological responses and environmental adaptability mechanisms to simulated drought and successive rewatering events in the early growing season.This was done by monitoring and regulating the soil volumetric water content of potted plants.The results showed that the photosynthetic parameters of R.pseudoacacia seedlings grown under low soil moisture conditions differed significantly from those of seedlings grown under field capacity soil moisture(the control group,CK)(P<0.05)in the soil drying process.The net photosynthetic rate(P_(n)),transpiration rate(T_(r)),and stomatal conductance(G_(s)) of R.pseudoacacia decreased by more than 90%under drought treatment compared with those of plants in the CK group.No significant variation was found in the photosynthetic parameters of P.tabulaeformis seedlings.Under soil water stress,the photosynthetic capacity of R.pseudoacacia seedlings was affected by stomatal and non-stomatal limitation,while that of P.tabulaeformis seedlings was mainly regulated by the stomata.Following the drought and rewatering,the P_(n)of R.pseudoacacia seedlings returned to the control level later(at the ninth day of drought period)than that of P.tabulaeformis(at the sixth day of drought period).Overcompensation effects were observed in the photosynthetic parameters of seedlings of both species in the rewatering period.The photosynthetic characteristics of the two tree species differed in response to the durations of drought(D_(n))and rewatering(W_(n))periods.P_(n),G_(s),and T_(r) of R.pseudoacacia seedlings gradually decreased with increase in D_(n)(P<0.05),and W_(n) was positively correlated with G_(s) and T_(r)(P<0.05).There was no significant correlation between the durations of drought and rewatering on the photosynthetic parameters of P.tabulaeformis seedlings.The variation in photosynthetic physiological parameters of the tree species was significan

关 键 词：刺槐 油松 干旱-复水 光合参数 水分利用效率 

分 类 号：S791.254[农业科学—林木遗传育种] S792.26[农业科学—林学]