湖南安息香属植物的叶片比较解剖学研究

利用光学显微镜和扫描电镜对湖南产安息香属10种植物叶表皮微形态和解剖结构进行了观察和测量。结果表明:(1)表皮均由单层细胞构成,细胞形状为多边形和无规则形,垂周壁式样为平直、弓形、波状;(2)气孔器大小及密度在种间的差异明显;(3)气孔外拱盖内缘主要为波状和浅波状,气孔器外围角质纹饰以越南安息香的鸟巢状和栓叶安息香的碗状为显著区别特征;(4)老鸹铃、垂珠花和白花龙的气孔器保卫细胞两极有"T"形加厚;(5)栓叶安息香和大果安息香叶上表皮由大型细胞组成;(6)叶肉分化为栅栏组织和海绵组织,二者的厚度及比值在种间有明显的差异,其中越南安息香栅栏组织分化为2层;(7)大果安息香和芬芳安息香的主脉维管组织构成一圈封闭的环状结构,而其他种则为开放的半圆形结构;(8)叶片及主脉的厚度在种间差异明显。安息香属植物的表皮微形态及解剖结构特征比较稳定,可作为种间鉴定和分类的重要依据。

Leaf Comparative Anatomy of Styrax(Styracaceae) in Hunan

The leaf epidermal micromorphology and anatomical structures of ten species in the genus Styrax from Hunan province in China were examined and statistically analyzed under light microscopy and scanning electron microscopy (SEM). The results were as follows: (1)The epidermis was composed of a single layer of cells which are polygonal or irregular in shape and their anticlinal walls are straight, arched, or sinuous; (2)The size and density of stomata apparatus between species are significantly different; (3)The inner margin of the outer stomatal rim of stomata apparatus is nearly sinuolate or sinuous, and the cuticular ornamentation around stomata apparatus is characteristically distinguished by the bird’s nest-like cuticular ornamentation of S.tonkinensis and the bowl-shaped cuticular ornamentation of S.suberifolius; (4)The T-shaped thickening at either polar region of stomatal guard cells is found in S.hemsleyanus, S.dasyanthus and S.faberi; (5)The upper epidermis of S.suberifolius and S.macrocarpus was composed of large cells; (6)The mesophyll was differentiated into palisade parenchyma and spongy parenchyma, and the thickness of palisade parenchyma and spongy parenchyma and the ratio of palisade to spongy thickness are distinctly different among species. The palisade parenchyma of S.tonkinensis is differentiated into two layers; (7)The main vein vascular tissues constitute a closed ring structure in S.macrocarpus and S.odoratissimus but an open semicircular structure in other species. The leaf epidermal micromorphology and anatomical structures can be used as an important basis for the identification and classification between species of Styrax, which is of some taxonomic significance.