| 金缕梅科(广义)的叶表皮特征 |
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| 引用本文： | 潘开玉,路安民,温洁.金缕梅科(广义)的叶表皮特征[J].中国科学院研究生院学报,1990,28(1):10-26. |
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| 作者姓名： | 潘开玉 路安民 温洁 |
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| 摘 要： | 本文次氯酸钠及铬酸-硝酸离析法，在光学显微镜下，观察了19属37种(分属六个亚科)共50个样品的成熟叶表皮细胞及气孔器的特征，发现金缕梅科植物叶上下表皮细胞形状(表面观)为多边形和不规则形，垂周壁式样有平直、弓形和有波纹；气孔器仅在下表皮存在，其类型有环列型、冠列型，平列型和无规则型(图1)几种。在扫描电镜下观察了19属35种(分属六个亚科)的叶下表皮的角质膜和蜡质纹饰、气孔的形状、气孔外拱盖及拱盖内缘的特征。这些特征在亚科或属级水平上较为稳定，但有的也表现出种间差异，有一定的分类学价值。
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| 关 键 词： | 金缕梅科 叶表皮 气孔器 |
Characters of Leaf Epidermis in Hamamelidaceae (s. l.) |
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| Pan Kai-Yu,Lu An-Ming,Wen Jie.Characters of Leaf Epidermis in Hamamelidaceae (s. l.)[J].Journal of the Graduate School of the Chinese Academy of Sciences,1990,28(1):10-26. |
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| Authors: | Pan Kai-Yu Lu An-Ming Wen Jie |
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| Abstract: | Observed under LM in the present work were epidermal cells and stomatal
apparatuses of mature leaves in 37 species (50 samples) belonging to 19 genera and 6 sub-
families (Hamamelidaceae), of which 35 species (19 genera, 6 subfamilies) were also used for
observing under SEM cuticular membrane and wax sculpture, shape of stomata and stucture
of stomatal apparatuses of the lower epidermis.
(1) It is found that in the family cells of both upper and lower epidermis are tetragonal,
pentagonal and hexagonal or irregular; anticlinal walls are straight, arched, sinuolate and sin-
uate; stomatal apparatuses, which occur only on the lower surface, may be cyclocytic, stephano-
cytic, paracytic and anomocytic. All these characters of the leaf epidermis are of systematic
significance in the family (Fig. 1).
(2) Types of stomatal apparatuses are correlated to a certain extent with the pattern of
anticlinal walls of epidermal cells and other external morphological characters. In the majority
of cases, the groups, whose stomatal apparatuses are cyclocytic (Exbucklandioideae and Rhodo-
leioideae) and stephanocytic (Mytilaria Lec. and Tetrathyrium Benth.), all have straight or
arched anticlinal walls of lower and upper epidermal cells (except for Exbucklandia tonkin-
ensis with sinuate anticlinal walls of both upper and lower epidermal cells, and E. longipetala
with sinuate anticlinal walls of upper epidermal cells) (Plate 1:12, 13; 2:4), are all evergreen
trees or shrubs, and all have palmate veins and simple hairs (but Rhodoleioideae is pinnate-
veined or obscurely trinervious and has tufted hairs), indefinite floral parts and numerous ovu-
les, while the groups, whose stomatal apparatuses are paracytic (Disanthoideae, Chunia H.
T. Chang, Liquidambaroideae and Hamamelidoideae, which also has anomocytic type in small
portion of species) (Table 2), have sinuolate or sinuate anticlinal walls of upper and lower
epidermal cells (except for Chunia, Tetrathyrium, Corylopsis brevistyla and C. willmotiae,
which have straight and arched anticlinal walls), are mostly deciduous trees and shrubs, and
have pinnate veins and tufted hairs in most species, usually tetra-, or pentamerous flowers (ex-
cept for Liquidambaroideae, which has indefinite floral parts) and usually single ovule (but
Disanthoideae and Liquidambaroideae have numerous ovules).
(3) The subfamily Liquidambaroideae possesses polyporate pollen grains (Chang 1958,
1979), a circular vascular system in the midrib, at the centre of which is situated a secretory
channel (Huang 1982, 1986) and leaf teeth of the unique Altingioid tooth type (Li 1988) etc.
Based on these characters some authors tend to support the separation of the subfamily as a
family, Altingiaceae. The subfamily, however, shows strong differentiation of characters. For
example, in the subfamily, there are both evergreen and deciduous trees, palmate and pinnate
leaf veins, capitate, short-spicate and racemose inflorescences and half-interior and inferior ov-
aries. Furthermore, some characters in the subfamily, which are considered important for the
separation, are crisscross with those ih the other members of the Hamamelidaceae. Their sto-
matal apparatuses are similar to those in most groups of Hamamelidaceae (paracytic), and
Sycopsis sinensis also possesses polyporate pollen grains. The subfamily shares with the remain-
ing members of Hamamelidaceae many important characters, such as the presence of stipule,
two styles, 2-locular ovary, axial placenta, capsule. From the data available the separation of
the subfamily does not seem to be supported by adequate evidence, and it may well be a link
of the Hamamelidaceae with the related families.
(4) Considering the fact that the subfamily Disanthoideae and most members of the su-
bfamily Hamamelidoideae are of paracytic stomatal apparatuses and pentamerous flowers, the
present authors tend to agree with Huang's (1986) view that the subfamily Disanthoideae is
more closely related than the other subfamilies to Hamamelidoideae.
(5) Leaf epidermis of the family under study shows great diversity under SEM, even
within a genus in some cases, but it is generally stable at subfamily or genus level, and there-
fore SEM characters of the leaf epidermis is of certain taxonomic significance. For example,
Exbucklandioideae possesses ovate stomata. The cuticular membrane is annular around stomata
(Plate 3:3-6); most stomata are covered with lump-like cuticular membranes in Rhodoleio-
ideae (Plate 3:7,8,11,12); in Mytilaria the cuticular membrane appears lump-like, with a
minute-scaly waxy ornamentation (Plate 3:9); the cuticular membrane is striate, with large
scales on it in Chunia (Plate 3:10), and it is vermicular in Sycopsis (Plate 5: 9-11). Some
differences were also found among species in a genus, for instance, among the three species inCorylopsis (Plate 4:12-14 and Table 2). |
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| Keywords: | Hamamelidaceae Leaf epidermis Stomatal apparatuses |
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