会议名称：2013 杉木文化国际研讨会
　　　　　2013 International Wood Culture Symposium on Taxodiaceae
会议时间：2013年10月26-27日
会议地点：中国湖南省长沙市·中南林业科技大学
报 告 人：杨永
　　　　　中国科学院植物研究所系统与进化植物学国家重点实验室

摘要：
　　植物分类学研究是在确定亲缘关系的基础上对植物分门别类。尽管以Stuessy 为代表的一些植物学家出于保护实践的考虑，主张容许并系分类（paraphyletic classification）的存在（如：Hörandl & Stuessy 2010），单系（monophyly）已经是Hennig提出分支分类学以来逐渐被众多学者认可的分类标准之一（Ebach et al. 2006），即一个分类群就是一个单系群。

　　杉科（Taxodiaceae）隶属于裸子植物松柏类。裸子植物在地球上已有约3.8亿年的历史，经历了古生代的发展和中生代的繁盛，在白垩纪被子植物繁盛以后，裸子植物逐渐绝灭，目前地球上还残存1000余种，包括苏铁类、银杏类、松柏类和倪藤类。松柏类裸子植物传统上被分为7个科，即松科（Pinaceae）、杉科、柏科（Cupressaceae）、南洋杉科（Araucariaceae）、罗汉松科（Podocarpaceae）、红豆杉科（Taxaceae）和三尖杉科（Cephalotaxaceae）。近几十年来的研究表明杉科的组成复杂，应重新分类。

　　杉科多为孑遗植物，现存属多为单型属或寡型属。裸子植物传统的分类系统以Pilger (1926)为典型，该系统记载当时已知杉科8属，即金松属（Sciadopitys Sieb. et Zucc.）、 北美红杉属（Sequoia Endl.）、落羽杉属（Taxodium Rich.）、水松属（Glyptostrobus Endl.）、柳杉属（Cryptomeria D. Don）、密叶杉属（Athrotaxis D. Don）、台湾杉属（Taiwania Hayata）和杉木属（Cunninghamia R. Br.）。巨杉属（Sequoiadendron Buchholz）和水杉属（MetasequoiaMiki ex Hu et Cheng）当时尚未建立。1978年出版的《中国植物志》第七卷记载杉科现存10属16种，即金松属、杉木属、台湾杉属、水松属、柳杉属、落羽杉属、水杉属、巨杉属、北美红杉属和密叶杉属，而Flora of China中记载杉科9属12种，将金松属独立为金松科。Page (1990)记载杉科9属16种，也将金松属单列一科。

多学科证据均支持杉科和柏科合并。基于形态特征的表型分析（Eckenwalder 1976）和分支分类学研究（Hart 1987），基于蛋白质免疫反应的免疫学研究（Price & Lowenstein 1989），以及基于DNA测序的分子系统学研究（如：Brunsfeld et al. 1994; Gadek et al. 2000; Kusumi et al. 2000; Chaw et al. 2000; Gugerli et al. 2001; Li & Yang 2002; Ran et al. 2010）， 均表明传统的杉科是一个复杂类群：金松属与杉科其他类群关系较远，应独立为金松科，杉科其余9属构成一个并系群，将柏科包含在内才构成一个单系群。细胞学特征也是一个重要证据。金松科的染色体基数为10，而杉科和柏科的染色体基数均为11（Page 1990; Li 1989, 1998）。因此，进入21世纪以来的裸子植物分类系统，通常将杉科与柏科合并构成广义柏科，如Fu et al. (2004)和Christenhusz et al. (2011)，柏科学名Cupressaceae与杉科学名Taxodiaceae均为保留名，在所有可用科名中，Cupressaceae发表最早，有优先权，因此，合并后应采用柏科Cupressaceae。

Abstract: Modern taxonomy of plants is based on phylogeny. Monophyly is one of the requirements of taxonomy since Hennig (1966) proposed the cladistics. A taxon is a monophyletic group and should consist of all descendents from a common ancestor.

Gymnosperms originated ca. 380 Ma years ago, and experienced diversification in the Palaeozoic and blooming in the Mesozoic, and have gone extensive extinction since Cretaceous radiation of angiosperms. This group of seed plants is now represented by only ca. 1000 living species worldwide, including cycads, Ginkgo L., conifers, and Gnetales.

Traditionally, conifers were classified into seven families since Pilger (1926), including Pinaceae, Taxodiaceae, Cupressaceae, Araucariaceae, Podocarpaceae, Taxaceae, and Cephalotaxaceae. This traditional classification was modified recently due to molecular phylogenetic studies and other data (e.g. cytology, immunology, cladistics) accumulated in the last several decades. Incorporation of Taxodiaceae into Cupressaceae is one of the major points in the new system Christenhusz et al. (2011).

Most of the Taxodiaceous plants are relics, and the living genera are monotypic or represented by only a few species. According to Flora Reipublicae Popularis Sinicae published in 1978, Taxodiaceae have 10 extant genera and 16 species, they are: Sciadopitys Sieb. et Zucc., Cunninghamia R. Br., Taiwania Hayata, Glyptostrobus Endl., Cryptomeria D. Don, Taxodium Rich., Metasequoia Miki ex Hu et Cheng, Sequoiadendron Buchholz, Sequoia Endl., and Athrotaxis D. Don, and Fu et al. (1999) recorded 9 genus and 12 species by excluding Sciadopitys into a different family Sciadopityaceae and reducing a few species in Flora of China. Page (1990) thought there are 9 genera and 16 species in the family, he also excluded Sciadopitys from Taxodiaceae. These considerations were mainly based on macromorphological characters. Eckenwalder (1976) first proposed to merge Taxodiaceae into Cupressaceae based on a phenological analysis of 46 characters including morphology, cytology, palynology, anatomy, and embryology. Based on a cladistic analysis of 123 characters of 63 genera of conifers, Hart (1987) arrived at a same conclusion that Sciadopitys should be segregated into a separate family, Taxodiaceae are monophyletic if Cupressaceae are included. Price & Lowenstein (1989) conducted an analysis of radioimmunoassay of seed protein extracts of Sciadopityaceae, Taxodiaceae, and Cupressaceae and got the same conclusion. Cytology gives rise to additional evidence for this conclusion: the base number of chromosomes is n=10 in Sciadopityaceae, but n=11 in Taxodiaceae and Cupressaceae. These results on familial relationships are corroborated by modern molecular systematics, e.g. Brunsfeld et al. (1994), Gadek et al. (2000), Kusumi et al. (2000), Chaw et al. (2000), Gugerli et al. (2001), Li & Yang (2002), and Ran et al. (2010). Both Taxodiaceae and Cupressaceae are conserved names, the familial name Cupressaceae is to be adopted when the two families are merged because this name is published earlier. As a result, a few new classification systems of gymnosperms adopted Cupressaceae in a broad sense including the traditional Taxodiaceae, e.g. Fu et al. (2004) and Christenhusz et al. (2011).

Speaker Profile
　　杨永，中国科学院植物研究所副研究员，硕士生导师。1997年毕业于内蒙古大学生物系，2002年在中科院植物所获博士学位并留所工作。致力于种子植物分类学、系统演化、区系地理研究和保护等方面的工作，重点是裸子植物和被子植物樟科的分类和系统演化研究，以及物种濒危状况评估和保育。曾在BMC Evolutionary Biology、Plos One、American Journal of Botany、Taxon、International Journal of Plant Sciences、Plant Systematics and Evolution 和Systematic Botany 等国际、国内专业期刊上发表多篇文章。

Dr. Yang Yong has been working extensively on systematics of seed plants for Institute of Botany, Chinese Academy of Sciences. His research fields include morphology, anatomy, ontogeny, palaeobotany, molecular, biogeography, and conservation. He is authored or co-authored for over 70 publications during the last 14 years.

Together with his collaborators, Dr. Yang described 2 macrofossil genera from the Early Cretaceous (Alloephedra Tao et Y. Yang and Chengia Y. Yang et al.), 4 new macrofossil species from the Early Cretaceous (Alloephedra xingxuei Tao et Y. Yang, Ephedra carnosa Y. Yang et Q. Wang, Ephedra archaeorhytidosperma Y. Yang et al., and Chengia laxispicata Y. Yang et al.), and 4 modern species (E. rituensis Y. Yang et al., E. dawuensis Y. Yang, Beilschmiedia turbinata Bing Liu et Y. Yang, and Caryodaphnopsis malipoensis Bing Liu et Y. Yang), and discussed the origin and evolution of Ephedraceae.

Dr. Yang holds a Bachelor degree on Microbiology from Biology Department of Inner Mongolia University, China, and a Ph.D degree of botany from the Graduate School of Chinese Academy Sciences. He visited the Missouri Botanical Garden during 2002 and 2003, and worked there on Asian Lauraceae for one year with Prof. Henk van der Werff who is one of the few specialists of Lauraceae.