木槿三个种下类群叶片的比较解剖学研究

Comparative anatomy of leaf blades in three infraspecies of Hibiscus syriacus

对紫花单瓣木槿、紫花重瓣木槿和牡丹木槿叶的解剖学性状进行了比较研究。结果表明:(1)三个种下类群的叶片均为典型双子叶植物背腹型叶,表皮细胞1层,角质膜不发达,上、下表皮均有相当数量的气孔,其中下表皮气孔密度更大;栅栏组织细胞长柱型,细胞层数1～2层,排列紧密,海绵组织细胞排列紧密,发达的叶脉具明显的机械组织。这些特点表明木槿三个种下类群对高湿高温生境具有较强的适应性;(2)三个种下类群在叶的解剖学性状上存在一定的差异,且牡丹木槿与其它两个种下类群之间的差异更为显著,表明具有独特的进化历程和对生境的生态适应策略。研究结果支持将牡丹木槿提升为亚种等级的建议。

Comparative anatomy of the leaf blades in Hibiscus syriacus f. syriacus,H. syriacus f. vioiaceum and H. syriacus L paeoniflorus is studied in this paper. The results are as follows: (1)Leaf blades of the three infraspecies are all typical back-abdomen type leaves of dicotyledons,the epidermis were formed by one layer of cells in which there are many stoma distributed,especially in lower epidermis;The palisade tissue consists of one to two layers of cells which line up densely,and cells of the elementary tissue line up densely,too. Main leaf vein was comparatively developed with obvious mechanical tissues. All these traits indicate that the three infraspecies of H. syriacus have stronger adaptability to high temperature and timid habitat. (2)There are some significant differences existing among the three infraspecies of H. syriacus in the anatomic characters of the leaf blades,the difference between H. syriacus f. paeoniflorus and the others is more notable,and it is show that H. syriacus f. paeoniflorus has different ecological adaptive strategics and evolutionary process, the results support the propose to regard H. syriacus f. paeoniflorus as a subspecies of H. syriacus.