兰属春剑叶艺突变体叶片结构的研究

以兰属春剑(Cymbidium tortisepalum Fukuy.var.longibracteatum)叶色突变体‘隆昌素’及其亲本为材料,采用石蜡切片、扫描电镜及透射电镜对叶片的组织结构、扫描结构和超微结构进行了观察。结果显示,春剑叶色突变体叶片的表皮厚度和叶肉细胞面积均大于亲本,但导管数量少于亲本;叶片上、下表皮纹饰与亲本具有明显差异;气孔密度和面积均小于亲本,且气孔闭合度较大,占总气孔数的56%;突变体的叶绿体呈高密度的囊泡状结构,内部严重解体,体积较小的嗜锇滴聚集分布,无基粒片层,无淀粉粒。本研究表明经组培诱变的春剑叶色突变体的叶片结构与亲本存在明显差异。

Structure of leaf variegation in Cymbidium tortisepalum Fukuy. var. longibracteatum

To explore the mechanism and provide a theoretical basis for the development and utilization of color mutants, Cymbidium tortisepalum Fukuy. var. longibracteatum with verge line pattern leaves and its parent leaves were used to investigate the characteristics of leaf variegation by paraffin section, scanning electron microscopy, and transmission electron microscopy. Results showed significant differences in the anatomical structure between the mutant and its parent. The epidermal thickness and mesophyll cell area of the mutant leaves were larger than those of the parent, whereas the number of vessels was lower. Scanning electron microscopy showed obvious differences in the micro-characteristics of the leaf surface between the mutant and parent. Stomatal area and density were smaller in the mutant leaves than that of the parent; furthermore, stomatal closure was higher in the mutant leaves than in the parent, with a frequency of 56% of the total number of stomata. Transmission electron microscopy showed no grana lamellae or starch grains, but many osmiophilic droplets in the mutant leaves, and the membrane of the chloroplast was disjointed. These results showed significant differences in the leaf structure between the mutant induced by tissue culture and its parent.