中国瓜馥木属植物叶片结构的解剖观察

采用叶片表皮离析法、扫描电镜和石蜡制片法,研究了中国分布的番荔枝科瓜馥木属19种植物叶片的形态结构。结果表明:瓜馥木属叶片形态和结构具有较多的相似性,如叶片表皮均具有2-多个细胞的单列丝状毛,表皮细胞内具有一个晶簇,气孔器均为平列型,只分布在叶片的远轴面,远轴面的表皮细胞平周壁形成一个乳突,叶片主脉的维管组织除具有正常的维管组织外,还具有一个小的副维管束等,这些特征有助于区分番荔枝科植物的属间关系,支持瓜馥木属是一个很自然的类群。但叶片表皮毛的形态及分布,表皮细胞的形状、叶肉中栅栏组织和海绵组织的结构、远轴面的乳突大小以及叶主脉维管组织的细微结构则具有种间差异。尤其有助于区分小萼瓜馥木和黑风藤、广西瓜馥木和独山瓜馥木、上思瓜馥木和东方瓜馥木等形态相似、难以区分的植物种类。该研究结果为该属的系统研究和种间正确区分提供了重要资料。

Comparative anatomy on leaves of Fissistigma (Annonaceae)from China

Leaf morphology and structures of nineteen species of Fissistigma from China were studied using epidermal maceration, scanning electron microscope and paraffin section method. The results showed that the anatomical feathers of Fissistigma revealed a remarkable consistency. The leaf surface of Fissistigma were covered with bicellulate or multicellulate uniseriate trichomes. The epidermal cells contained one clustered crystal. The stomatal apparatus were paracytic with two to four subsidiary cells and only distributed on abaxial epidermis. The outer percilinal walls of abaxial epidermal cells were papllate. In the leaf midrib, there was one additional vascular strand except for normal vascular tissues. Therefore, these anatomical feathers should be contributed to differentiate the relationship among genera and support that Fissistigma is a natural group in Annonaceae. However, the form and distribution of trichomes, the shape of epidermal cells, the structures of mesophyll tissues, the sizes of papllate cells and the precise vascular structures in midrib vary obviously with species. Also, these anatomical differences between species may be used to distinguish some perplexing species such as F. minuticalyx and F. polyanthum, F. kwangsiense and F. cavaleriei, F. tungfangense and F. shangtzeense.