桔梗、射干的耐阴性研究

为了探讨桔梗和射干的耐阴性，采用黑色遮荫网遮荫，设置了5种光强处理(各处理透光率分别为：对照100％、T1：75％、T2：65％、T3：50％、T4：25％)，对其不同遮荫条件下的株高生长、地径生长、分蘖数、叶生长性状、叶绿素含量、光合性能、叶绿素荧光参数(Fv／Fm值)和生物量进行了测定。结果表明，射干对遮荫的适应能力较强，适当的遮荫有利于射干分蘖数、单株叶面积、叶绿素含量、日平均光合速率的增加，在透光率为71．45％的光照条件下其总生物量最高，为较耐阴的植物；而桔梗对遮荫的适应能力较差，遮荫会导致其分蘖数、单株叶片数、单株叶面积减少，日平均光合速率的下降，生物量以全光为最大，为喜阳植物，但其对轻微的遮荫处理(T1和T2处理)也有一定的适应性。

Study on the shade-endurance of Platycodon grandiflorum(Jacq.)A.DC.and Belamcanda chinensis(L.)DC.

To discuss the shade-endurance of Platycodon grandiflorum(Jacq.)A.DC. and Belamcanda chinensis(L.)DC., the black shading net was used to provide five kinds of light intensity( light permeance rate was separately as flows: contrast: 100%, T_1:75%, T_2:65%,T_3:50%,T_4:25%).Under the different shading intensity, the primary indexes including plant height, stem diameter, stem number, leaf growth, photosynthesis capability, the parameter of chlorophyll flurescene(F_v/F_m) and biomass were measured. The results showed that the shading adaptability of Belamcanda chinensis(L.)DC. was better, proper shading was good to the increasing of stem number, leaf area of individual plant, chlorophyll content and daily average photosynthetic rate, the biomass was highest when the light permeance rate was 71.45%, so Belamcanda chinensis(L.)DC. likes shading environment. On the contrary, the shading adaptability of Platycodon grandiflorum(Jacq.)A.DC. is not very good, shading will result in the decreasing of stem number, daily average photosynthetic rate, leaf number and leaf area of individual plant, the biomass is biggest when the light permeance rate is 100%, so Platycodon grandiflorum(Jacq.)A.DC. likes light environment, on the other hand, it can adapt to the environment where the shading is not serious.