巨桉凋落叶分解对菊苣生长及光合特性的影响  

Effects of Eucalyptus grandis leaf litter decomposition on the growth and photosynthetic characteristics of Cichorium intybus

作　　者：吴秀华[1] 胡庭兴[1] 杨万勤[1] 陈洪[1] 胡红玲[1] 涂利华[1] 泮永祥[1] 曾凡明[1] 

机构地区：[1]四川农业大学林学院林业生态工程四川省重点实验室,四川雅安625014

出　　处：《应用生态学报》2012年第1期1-8,共8页Chinese Journal of Applied Ecology

基　　金："十一五"国家科技支撑计划项目(2008BADC2B01);四川省重点学科建设项目(SZD0419);四川农业大学"211工程"建设项目资助

摘　　要：采用盆栽试验,研究了巨桉凋落叶分解初期对菊苣幼苗生长和光合生理特性的影响.试验设置A1(30g·pot-1)、A2(60g·pot-1)、A3(90g·pot-1)和对照(CK)4个凋落叶水平,将各处理的凋落叶分别与12kg土壤混合后装盆,播种菊苣.待A3处理植株的第3片真叶完全展开后测定菊苣光合生理指标及相关生长指标.结果表明:巨桉凋落叶分解初期明显抑制了菊苣生物量积累、叶面积的增加及光合色素的合成,且随着凋落叶施入量的增加抑制作用加大;菊苣叶片胞间CO2浓度增加,而净光合速率、气孔导度和蒸腾速率均显著低于对照;随土壤中凋落叶含量的增加,除CO2补偿点呈增加趋势外,其他光响应和CO2响应的特征参数都呈明显下降趋势,并与对照差异显著.巨桉凋落叶分解过程中,其化感物质逐步释放并作用于受体植物,抑制其光合色素合成和光合作用,降低其环境适应能力,从而抑制菊苣的生长.A pot experiment was conducted to study the effects of Eucalyptus grandis leaf litter during its early stage decomposition on the growth and the photosynthesis of Cichorium intybus. Each pot contained 12 kg soil mixed with different amounts of E. grandis leaf litter （30 g·pot-1, A1; 60 g·pot-1, A2; 90 g·pot-1, A3; and 0 g·pot-1, CK）, and sowed with C. intybus. The growth indicators and the photosynthetic characteristics of C. intybus were measured after the third leaf of C. intybus seedlings fully expanded in treatment A3. At the early stage of leaf litter decomposition, the C. intybus biomass accumulation, leaf area growth, and synthesis of photosynthetic pigments were inhibited significantly, and the inhibition effect was getting stronger with the increasing amount of the leaf litter addition. The intercellular CO2 concentration of C. intybus was increased by litter addition, while the net photosynthetic rate, stomatal conductance, and transpiration rate were significantly lower than those of the control. With the increase of leaf litter addition, all the parameters of C. intybus light response and CO2 response except CO2 compensation point showed an obvious downward trend, and there existed significant differences between the treatments of litter additions and the control. It was suggested that during the decomposition of E. grandis leaf litter, its allelopathic substances released gradually and acted on receptor plants, inhibited the synthesis of photosynthetic pigments and the photosynthesis of the receptors, decreased the receptors environmental adaptation ability, and accordingly, inhibited the growth of C. intybus.

关 键 词：巨桉 凋落叶 菊苣 化感 光合作用 农林复合系统 

分 类 号：S792.39[农业科学—林木遗传育种] Q948[农业科学—林学]