遮荫对掌叶半夏生长、产量及光合生理特性的影响研究

Effects of Shading on Growth,Yield and Photosynthesis Physiological Characteristics of Pinellia Peda-tisecta Schott

目的:研究遮荫对掌叶半夏生长、药材产量和光合生理指标的影响,分析适宜掌叶半夏药材高产的遮荫度,探寻其产量差异形成的光合生理机制。方法:采用遮荫网遮荫,共设置了5种光强处理,透光率分别为全光对照CK(100%)、T1(75%)、T2(65%)、T3(50%)、T4(25%),测定各遮荫处理下掌叶半夏的株高、单株叶片数、单株叶面积、单片叶面积、药材产量、叶绿素含量、光合日进程和叶绿素荧光参数。结果:(1)遮荫可显著(P<0.01)提高掌叶半夏的株高、单株叶面积和叶绿素含量;(2)光合日进程曲线测定结果表明,除T4处理外其他处理均发生光合"午休"现象,日平均光合速率(Pn)以T1处理最高,绝对光能利用率(Eu)以T3处理最高;(3)叶绿素荧光参数测定结果表明,CK的Fv/Fm最低,发生的原因可能与PSⅡ反应中心的光化学伤害有关;(4)药材产量以T2处理最高,较CK增产56.34%。结论:掌叶半夏更适宜在遮荫条件下栽培,透光率在65%时有利于掌叶半夏药材高产,其产量差异的形成可能与日均光合速率的不均衡有关。

Objective： To investigate the effect of shading on growth,yeild and photosynthesis physiological characteristics of Pinellia peda-tisecta Schott,to analysis the proper shading for high-yield of Pinelliae rhizoma,and to explore the mechanism of photosyn-thetic physiology as for its variance of yeild.Method： Adopt plastic net to shade,five different kinds of light intensities were set,with the light transmittance were controled group CK（100%）,T1（75%）,T2（65%）,T3（50%）,T4（25%） respectively.Pinellia peda-tisecta Schott＇s plant height,the number of one plant laminas,the leaf area of one plant lamina,the area of one leaf,the yeild of Pinelliae rhizoma,the content of chlorophyll,photosynthesis process,and chlorophyll fluorescence parameters in different kinds of shading were detected re-spectively.Result：（1）Shading increased the plant height,the whole leaf area of one plant lamina,and the content of chlorophyll observ-ably（P0.01）;（2）All treatment would had midday depression phenomenon except T4 treatment,the highest average photosynthetic rate（Pn） in one day was T1 treatment,and the absolute efficiency of light energy utilization was T3 treatment;（3）The Fv/Fm of CK was the lowest,and the probable reason might be connected with the harm of photochemistry of the reaction center of PSⅡ;（4）The highest of yield of Pinelliae rhizome was T2 treatment,which was 56.34% and it was higher than that inCK treatment.Conculusion： Pinellia pe-da-tisecta Schott are more suitable to cultivation on the condition of shading.The yield of Pinelliae rhizome was higher when the light transmittance was in 65%.The difference of the yield of Pinelliae rhizome might be related with the imbalance of a day average photo-synthetic rate.