巨桉凋落叶分解初期对小白菜光合生理特性的影响  

Effects of Allelopathy from the Early Decomposition of Eucalypt Leaf Litter on the Photosynthetic Characteristics of Brassica chinensis L

作　　者：陈良华[1] 弓平[1] 杨万勤[1] 张健[1] 胡庭兴[1] 

机构地区：[1]四川农业大学林学院,四川雅安625014

出　　处：《四川农业大学学报》2012年第2期174-180,共7页Journal of Sichuan Agricultural University

基　　金："十二五"国家科技支撑计划课题(No.2011BAC09B05)

摘　　要：【目的】探讨巨桉凋落叶化感物质对受体植物光合效率及光合机构的影响。【方法】采用向栽植盆中直接施加巨桉凋落叶的方法,模拟巨桉凋落叶化感物质自然释放过程,分别设置0、20、40、80、120g/盆等5个巨桉凋落叶施用水平,选择受体作物小白菜进行盆栽控制实验。【结果】随着巨桉凋落叶施用量的增加,小白菜的各种色素含量显著下降,叶绿素a降幅最大,最高处理量(120g/盆)的小白菜叶绿素a比对照降低了67.3%;Pn-PAR曲线和Pn-Ci曲线的曲角也不断减小,光饱和下AQY、Pmax、Lsp、Lcp、Rd以及CO2饱和下CE、Pmax、Rp等拟合参数也呈总体降低的趋势,Ccp逐渐升高,Csp无明显规律;光适应下Fo'、Fm'、Fs、Fv'/Fm'、ΦPSⅡ、qP、qN等叶绿素荧光参数值也显著下降,80和120g/盆两个处理与对照差异显著(P<0.05)。【结论】巨桉凋落叶分解初期释放的化感物质显著地抑制了小白菜的光合作用,表现出明显的光抑制特征,光反应系统受到损害。[Objective] Our aim is to investigate effects of allelopathy from the early decomposition of Eucalypt foliar litter on photosynthesis efficiency and apparatus of Brassica chinensis. [Meth- od] A pot-experiment with five levels of Eucalypt leaf litter mass （0, 20, 40, 80, and 120 g per pot） were used to examine the impacts of allelopathy during natural releasing process of Eucalypt foliar litter on the photosynthesis of B. chinensis. [Results] The contents of pigments decreased with increasing Eucalypt foliar litter. The most significant decline happened to chlorophyll a. The greatest decrease rate （67.3%） of chlorophyll was observed at the highest level （120 g per pot）. The angle （θ） Pn-PAR and Pn-Ci curve, AQY, Lsp, Pmax under the photo-saturation and Pmax un- der the CO2-saturation, CE and Rp decreased （except for Cop and Csp） with Eucalypt litter addi- tion. Fo＇, Fm＇, Fs, Fv＇/Fm＇, φPSⅡ, , qp, qN were also decreased by litter addition. There were signif- icant differences in such parameters between control and level of 80 or 120 g per pot （P〈0.05）. [Conclusion] Our results indicated that the allelopathic substances released from Eucalypt leaf lit- ter significantly sbupressed photosynthesis of pakchoi, some extent, destroyed by the allelopathic substances.

关 键 词：化感作用 巨桉 小白菜 光合作用 叶绿素荧光 

分 类 号：S792.39[农业科学—林木遗传育种]