环草石斛和铁皮石斛试管苗叶片气孔特征比较  

Comparison of Stomatal Characteristics of Test-tube Seedling Leaves of Dendrobium loddigesii and Dendrobium candidum

作　　者：孙志蓉[1] 王美云[2] 张宏桂[1] 金家兴 李碧彪 

机构地区：[1]北京中医药大学中药学院,北京100102 [2]河北省廊坊市人民医院,河北廊坊065000 [3]贵州吉仁堂药业公司,贵州兴义562400

出　　处：《安徽农业科学》2011年第27期16583-16586,共4页Journal of Anhui Agricultural Sciences

基　　金："十一五"国家科技支撑计划项目(2006BAI06A11-11)

摘　　要：[目的]比较环草石斛和铁皮石斛试管苗叶片的气孔特征和光合特性,揭示试管苗生长发育的生理生态机制。[方法]对环草石斛和铁皮石斛不同生长发育时期试管苗叶片的气孔进行扫描电镜观察,并用调制式荧光仪测定荧光诱导光响应曲线。[结果]在各个生长发育时期,环草石斛试管苗叶片的气孔密度均明显高于铁皮石斛,而气孔开放率则较低。随着生长时间的延长,环草石斛和铁皮石斛试管苗叶片气孔的大小变化不大,而气孔的数量则逐渐增加,气孔密度分别增加了83.0%和17.6%,两者均以播种生长240 d时叶片的气孔开放率最高。在设定的3种光照强度下,环草石斛试管苗叶片气孔开放程度随光强的增加而增大,光强为54μmol/(m2.s)时气孔的开放度最大。在相同培养条件下,环草石斛试管苗的最大电子传递速率14μmol/(m2.s)和光饱和点318μmol/(m2.s)均低于铁皮石斛20、483μmol/(m2.s),其潜在的光合作用能力较差。[结论]不同种类石斛试管苗的气孔特性不同,因而光合速率也不同。遵循试管苗对光照强度的需求规律,选择合适的培养条件,增大气孔开度,提高光合速率,将更有利于试管苗的生长发育。[Objective] This study was to compare the leaf stomatal and photosynthetic characteristics of Dendrobium loddigesii and Dendrobium candidum,so as to reveal the physiological and ecological mechanism of growth and development of test-tube seedling.[Methods] Leaf stomata of test-tube seedlings of D.loddigesii and D.candidum at different growth and development stages was observed under scanning electron microscope,and their fluorescence induction response curve was assayed by using modulate fluorometer.[Results] At each growth and development stage,D.loddigesii test-tube seedling had a higher leaf stomatal density over D.candidum,while a lower stomata opening rate.Along with the growth,the size of stomata of both D.loddigesii and D.candidum did not change obviously,but their stoma density was increased by 83% and 17.6% respectively.Leaf stomata opening rate reached the highest at the age of 240.Under the conditions of three light intensities tested,stomatal opening degree of D.loddigesii was increased with the intensity of illumination raised,the maximum opening degree occurred at the light intensity of 54 μmol/（m2·s）.Given the same culture condition,both the maximum electron transport rate（14 μmol/（m2·s） and light saturation point（318 μmol/（m2·s）of D.loddigesii test-tube seedling were lower than that of D.candidum（20,483 μmol/（m2·s）.Moreover,the potent photosynthetic capacity of D.loddigesii was relatively poor.[Conclusion] The photosynthetic rate varied among different species of Dendrobium,which could be attributed to their different stomatal characteristics.Usually,the light intensity of tissue culture chamber was set up as 27 μmol/（m2·s）,both D.loddigesii and D.candidum did not acquire an optimal state for their leaf stomatal opening.Following the characteristics to select suitable culture condition,the stomatal opening degree and photosynthetic rate could be enhanced,which can promote the growth and development of test-tube seedlings.

关 键 词：环草石斛 铁皮石斛 组织培养 气孔 光合特性 

分 类 号：S567[农业科学—中草药栽培]