摘要
植物叶性状能够直接或间接反映植物对环境的适应策略。为了解大叶女贞在Pb胁迫下的适应策略,本研究以2年生大叶女贞(Ligustrum lucidum)为对象,设置土壤不同Pb污染水平(0、300、600和1800 mg·kg,分别以C_(i)K、L1、L2和L3表示),测定Pb处理下大叶女贞叶片的光合效率和叶片性状指标,分析它们之间的关系。结果表明:与对照相比,3个Pb处理下大叶女贞的净光合速率(P_(n))分别显著下降37.66%、57.73%和77.47%,最大光化学效率(F_(v)/F_(m))仅在L2和L3分别显著下降6.25%、12.50%。比叶面积(SLA)、叶绿素(C_(i)hl)、叶绿素a(C_(i)hla)、叶绿素b(C_(i)hlb)、叶磷含量(TP)、叶氮含量(TN)、氮磷比(N/P)均显著降低,胞间C_(i)O浓度(C_(i))和碳氮比(C_(i)/N)均显著增加,碳磷比(C_(i)/P)在L2、L3处理下显著增加,气孔导度(G_(s)_(s))和叶片厚度(LT)在L3处理下显著下降;相关性分析表明,SLA和叶绿素除与LT外,与其他性状参数均呈显著相关,N/P除与G_(s)和C_(i)外,与其他性状均呈显著相关;结构方程模型分析表明,气体交换和叶绿素是影响光合效率的直接因素,叶片表型和化学元素是影响光合效率的间接因素。主成分分析验证了Pb胁迫下大叶女贞叶经济谱的适应性,属于缓慢投资-收益型的一端。
Leaf traits could reflect plant adaptation strategies to environmental changes.In this study,we measured photosynthetic efficiency and leaf traits of Ligustrum lucidum under Pb stress and analyzed their relationships,aiming to understand the adaptive strategies of L.lucidum to Pb stress.Two-year-old L.lucidum was treated with four Pb concentrations(0,300,600,1800 mg·kg,designated as CK,L1,L2 and L3,respectively).The results showed that net photosynthetic rate(P_(n))was significantly reduced by 37.66%,57.73%,and 77.47%under L1,L2,and L3 treatments,respectively.The maximum photochemical efficiency(F_(v)/F_(m))of L.lucidum was only decreased significantly by 6.25%and 12.50%in L2 and L3,respectively.Specific leaf area(SLA),chlorophyll(Chl),chlorophyll a(Chla),chlorophyll b(Chlb),leaf phosphorus(TP),leaf nitrogen(TN),and nitrogen-to-phosphorus ratio(N/P)were significantly decreased.However,the intracellular COconcentration(C)and carbon-to-nitrogen ratio(C/N)were significantly increased in Pb treatments.Carbon-to-phosphorus ratio(C/P)was significantly increased under L2 and L3 treatments.Stomatal conductance(G_(s))and leaf thickness(LT)were significantly decreased under L3 treatment.SLA and Chl were significantly correlated with the leaf traits except LT.N/P was significantly correlated with the leaf traits except G_(s)and C_(i).Results of structural equation modeling showed that gas exchange and Chl directly affected photosynthetic efficiency,while leaf phenotype and chemical elements had indirect effects.Principal component analysis verified the adaptability of the leaf economics spectrum in L.lucidum under Pb stress,which belonged to the end of slow-investment-return in the leaf economics spectrum.
作者
孔佑莎
许洪扬
黄鑫浩
朱凡
KONG You-sha;XU Hong-yang;HUANG Xin-hao;ZHU Fan(CentralSouth University of Forestry and Technology,Changsha 410018,China;Hunan Agricultural University,Changsha 410125,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2022年第10期1881-1886,共6页
Chinese Journal of Ecology
基金
国家自然科学基金面上项目(32072672)
湖南省普通高等学校重点实验室(园林生态与规划设计)
中南林业科技大学2021年研究生科技创新基金项目(CX202102025)资助。
关键词
PB胁迫
叶片性状
光合效率
叶经济谱
大叶女贞
Pb stress
leaf trait
photosynthetic efficiency
leaf economics spectrum
Ligustrum lucidum
