薹草的耐阴性研究及园林适用环境分析

以吉祥草作参照,对条穗薹草、仲氏薹草、栗褐薹草和三穗薹草进行遮光梯度为0、50%、75%、90%的遮光处理后,测定5种植物的叶宽、叶长、叶绿素a+b、叶绿素a/b、光-光响应曲线和叶绿素荧光特性值。结果表明:随遮光度增加,5种植物的叶宽无显著变化,叶长、叶绿素a+b含量、Fv/Fm、Fv/F0和Fv′/Fm′增加,叶绿素a/b、光补偿点和qN降低;仲氏薹草和三穗薹草的叶绿素a+b含量在遮光75%下达到最高,叶绿素a/b分别在遮光75%、50%下达到最低;栗褐薹草、仲氏薹草和三穗薹草的光饱和点在遮光50%下最大,条穗薹草和吉祥草分别在遮光0和75%下最大。综合分析表明:5种植物的耐阴能力由强到弱依次为栗褐薹草、吉祥草、条穗薹草、三穗薹草、仲氏薹草;条穗薹草和栗褐薹草对光照的适应范围较宽,而吉祥草、仲氏薹草和三穗薹草较窄。结合野外生境调查结果表明:条穗薹草适宜在水库边、河道旁的死水区和水位变化区等生态环境下栽种;栗褐薹草可用于林下、建筑北侧、桥梁下空地等荫蔽性较强处栽种;三穗薹草和仲氏薹草则因耐阴性弱,适宜于在常绿阔叶林林缘、路边坑边草丛中、山坡灌丛等环境下栽种。

Evaluation of shade tolerance of Carex species available for garden-environment planting

The grass species,Carex nemostachys,C.chungii,C.brunnea and C.tristachya,were selected to investigate their shade-tolerance,with Reineckia carnea as control.Their morphological and physiological characteristics,i.e.lengths and widths of leaves,chlorophyll content (Chl a + b),the chlorophyll a /b ratio (Chl a /b),photosynthetic light-response curves and chlorophyll fluorescence,were investigated.There were no significant differences in leaf width when the degree of shade ranged from 0 to 90% ;leaf length,Chl...