Variation and Evolution of Leaf Trichomes in the Chinese Hamamelidaceae

Abstract

Abstract:

Leaves of 25 species which cover 13 genera of the Chinese Hamamelidaceae

(sensu lato ) were examined by light microscope (LM) and scanning electron microscope

(SEM) to reveal the nature and variation of trichomes. The trichomes showed greater di-

versity under SEM than under LM and naked eyes. Based on Theobald’s scheme, they

can be divided into four types:

1. Simple trichomes: Unbranched, curved or straight (Altingia, liquidambar,

Semiliquidambar; 2. 2- 4 armed trichomes: Two to four branched (Corylopsis,

Loropetalum, sinowilsonia); 3. Stellate trichomes: With more than five branches. They may be

tufted (Forthunearia, Loropetalum, sinowilsonia, Hamamelis, Distylium) or storied (Eustigma);

4. Scales: Peltate and flattened. In the genus Rhodoleia, the scales are totally composed of

small boat-shaped ones, whereas in the genus Sycopsis they are rotately branched on the

verge but unbranched and flattened in the middle.

The distribution of trichome types is of grest significance in hamamelidaceous

phylogeny. The simple trichomes mainly exist in Liquidambaroideae and

Exbucklandioideae, the stellate and 2-4 armed trichomes occur in Hamamelidoideae, and

the scales are confined to Sycopsis (Hamamelidoideae) and Rhodoleia (Rhodoleioideae).

From this fact, the authors consider that there are two evolutionary lines in the family,

i. e. the Disanthoideae- Exbucklandioideae- Liquidambaroideae line and the

Rhodoleioideae-Hamamelidoideae line though some subfamilies are isolated.

Within Hamamelidoideae, the trichome types also have taxonomic significance.

Corylopsis is a primitive group, whereas Eustigma, Distylium and Sycopsis are respectively

on the top of evolutionary branches and the other genera are transitional groups. These

genera might be separated as tribes, Corylopsideae, Eustigmateae, Distylieae, Sycopsideae

and Hamamelideae. The relationships among these tribes are given in Fig. l.

Key words: Hamamelidaceae, Trichomes, Micromorphology, Phylogeny

Fang Yan-ming, Fan Ru-wen. Variation and Evolution of Leaf Trichomes in the Chinese Hamamelidaceae[J]. .

[1]	WANG Ma-Li, CHEN Zhi-Duan, ZHANG Xian-Chun, LU Shu-Gang, ZHAO Gui-Fang. Phylogeny of the Athyriaceae: evidence from chloroplast trnL-F region sequences [J]. , 2003, 41(5): 416-426.
[2]	BI Hai-Yan, LIN Qi, LIU Chang-Jiang, ZHAO Jian-Cheng. Seed morphology of Kadsura Juss.(Schisandraceae) in relation to its taxonomic significance [J]. , 2002, 40(6): 505-510.
[3]	ZHANG Shu-Ren. Classification of Kobresia fragilis C. B. Clarke (Cyperaceae) and related taxa [J]. , 2002, 40(5): 433-443.
[4]	LUO Yan, ZHOU Zhe-Kun. Leaf epidermis of Quercus subgen. Cyclobalanopsis (Oerst.) Schneid. (Fagaceae) [J]. , 2001, 39(6): 489-501.
[5]	Friedrich Ehrendorfer, Rosabelle Samuel. Contributions to a molecular phylogeny and systematics of Anemone and related genera (Ranunculaceae-Anemoninae) [J]. , 2001, 39(4): 293-308.
[6]	ZHANG Zhi-Yun, ZHANG Hong-Da. New synonymies of some species in the Hamamelidaceae [J]. , 2000, 38(6): 575-577.
[7]	ZHAO Zuo-Cheng, ZHOU Ming-De, LUO Ding-Ze, SHEN Guo-Kun, HOU Xin. Morphological characteristics of fruits of Fagopyrum (Polygonaceae) from China [J]. , 2000, 38(5): 486-489.
[8]	ZHANG Wen-Ju, QU Li-Jia, GAO Wei, GU Hong-Ya, CHEN Zhang-Liang, CHEN Jia-Kuan. The phylogenetic relationships among the possible donors of B-genome of common wheat based on internal transcribed spacer (ITS) sequences [J]. , 1999, 37(5): 417-424.
[9]	SUN Kun, CHEN Jia-Kuan, CHEN Zhi-Duan. Progress in Studies on Floral Development of Angiosperms and Some Consideration on Future Studies [J]. , 1998, 36(6): 558-568.
[10]	WU Zheng-Yi, TANG Yan-Cheng, LU An-Ming, CHEN Zhi-Duan. On Primary Subdivisions of the Magnoliophyt—Towards a New Scheme for an Eight-class System of Classification of the Angiosperms [J]. , 1998, 36(5): 385-402.
[11]	WANG Xiao-Quan, DENG Zheng-Rong, HONG De-Yuan. The Systematic Position of Beesia: Evidence from ITS (nrDNA) Sequence Analysis [J]. , 1998, 36(5): 403-410.
[12]	FENG Yu-Xing, WANG Xiao-Quan, PAN Kai-Yu, HONG De-Yuan. A Revaluation of the Systematic Positions of the Cercidiphyllaceae and Daphniphyllaceae Based on rbc L Gene Sequence Analysis, with Reference to the Relationship in the “Lower” Hamamelidae [J]. , 1998, 36(5): 411-422.
[13]	WANG Xiao-Quan, LI Zhen-Yu. The Application of Sequence Analysis of rDNA Fragment to the Systematic Study of the Subfamily Cyrtandroideae (Gesneriaceae) [J]. , 1998, 36(2): 97-105.
[14]	HAO Ri-Ming, WEI Hong-Tu. A New Combination of Hamamelidaceae [J]. , 1998, 36(1): 80-80.
[15]	Li Jian-hua, A. Linn Bogle, Anita S. Klein, Pan Kai-yu. Close Relationship Between Shaniodendron and Parrotia (Hamamelidaceae), Evidence from ITS Sequences of Nuclear Ribosomal DNA [J]. , 1997, 35(6): 481-493.

Variation and Evolution of Leaf Trichomes in the Chinese Hamamelidaceae

Knowledge

Abstract

Cite this article

share this article

References

Related Articles 15

Recommended Articles

Metrics

Comments