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1.
柏科分类和分布:亚科,族和属   总被引:4,自引:0,他引:4  
柏科Cupressaceae和杉科Taxodiaceae有许多相似之处,近年来不少分类学家主张把两科合并成广义的柏科。原杉科中的金松属Sciadopitys与两科其他属的差异较大,被提升为单种科Sciadopity-aceae。本文根据球果可育种鳞的位置把柏科(狭义)分为2亚科,即上部种鳞不可育的柏木亚科Cupres-soideae和上部种鳞可育的澳洲柏亚科Callitroideae。综合其他形态学和解剖学证据,柏木亚科又分4族,即柏木族Cupresseae(包括:柏术属Cupressus、杂交柏属×Cupressocyparis、扁柏属Chamaecyparis和福建柏属Fokeinia)、侧柏族Thujopsideae(包括:崖柏属Thuja、罗汉柏属Thujopsis和侧柏属Platycladus)、圆柏族Junipereae(包括:圆柏属Juniperus和海参威柏属Microbiota)以及香漆柏族Tetraclineae(包括:翠柏属Calocedrus和香漆柏属Tetraclinis)。澳洲柏亚科又分3族,即澳洲柏族Actinostrobeae(包括:西澳柏属Actinostuobus、澳洲柏属Callitris、智利柏属Fitzroya和杉叶柏属Neocallitropsis)、南非柏族Widdring-toneae(包括:白智利柏属Pilgerodendron、塔斯曼柏属Diselma和南非柏属Widdringtonia)以及甜柏族Libocedreae(包括:甜柏属Libocedrus、巴布亚柏属Papuacedrus和南美柏属Austrocedrus)。柏科21个属的地理分布可划分为5种类型,即:(  相似文献   

2.
侧柏亚科三种植物的核型及其细胞分类学研究   总被引:7,自引:2,他引:5  
分析了北美乔柏、北美香柏和西方翠柏的核型,它们的核型公式分别为K(2n)=22=16m=16sm(2SAT),20m(2SAT)+2sm和20m(2SAT)+2sm。北美乔柏的核型为首次报道。经对侧伯亚科10个属(22种)的核型的比较分析,似见南半球5属和侧柏属及Tetraclinis最为原始,罗汉柏属和崖柏属最进化,翠柏属居中。本文还讨论了翠柏属、侧柏属及南半球属的分类位置。  相似文献   

3.
In order to develop better insights into biogeographic patterns of eastern Asian and North American disjunct plant genera, sequences of nuclear ribosomal DNA internal transcribed spacer (nr DNA ITS) region were used to estimate interspecific relationships of Thuja L. (Cupressaceae) and infer its biogeography based on the phylogeny. According to the phylogenetic analysis, two clades were recognized. The first clade included Thuja plicata D. Don (western North America) and T. koraiensis Nakai (northeastern Asia), and the second one contained T. occidentalis (Gord.) Carr. (Japan). The ancestral area of Thuja was inferred to be eastern Asia, and two dispersal events were responsible for the modern distribution of Thuja in North America. Both the North Atlantic land bridge and Bering land bridge were possible routes for the migration of ancestral populations to North America.  相似文献   

4.
Parsimony analysis of matK and rbcL sequence data, together with a nonmolecular database, yielded a well-resolved phylogeny of Cupressaceae sensu lato. Monophyly of Cupressaceae sensu stricto is well supported, and separate northern and southern hemisphere subclades are resolved, with Tetraclinis within the northern subclade; there is no support for any of the tribes sensu Li. Taxodiaceae comprise five separate lineages. Chamaecyparis nootkatensis falls within Cupressus, clustering with a robust clade of New World species. Libocedrus Florin is paraphyletic and should incorporate Pilgerodendron. Evolution of several characters of wood and leaf anatomy and chemistry is discussed in light of this estimate of the phylogeny; numerous parallelisms are apparent. A new infrafamilial classification is proposed in which seven subfamilies are recognized: Callitroideae Saxton, Athrotaxidoideae Quinn, Cunninghamioideae (Sieb. & Zucc.) Quinn, Cupressoideae Rich. ex Sweet, Sequoioideae (Luerss.) Quinn, Taiwanioideae (Hayata) Quinn, Taxodioideae Endl. ex K. Koch. The rbcL sequence for Taxodium distichum is corrected, and the implications for a previously published estimate of the minimum rate of divergence of the gene since the Miocene are highlighted.  相似文献   

5.
Six species of the Cupressaceae, the variegated Leyland cypress (Cupressocyparis leylandii 'Silver Dust'), savin (Juniperus sabina variegata Laws), davurian juniper (Juniperus davurica 'expansa variegata'), California incense cedar (Calocedrus decurrens 'Aureovariegata'), the American arbor vitae (Thuja occidentalis 'lutae zebrina' Kent), and the sawara false cypress (Chamaecyparis pisifera 'nana aureovariegata') were examined for the behavior of albino-green shoot chimeras. The fate of the variegations in these six plants is the same in two important respects. First, the majority (89%) of sprays with an original sector become completely white. Second, sectorial branch sprays of the original sectorial sprays become either completely green or white in a 1?:?1 ratio. Based on the first finding it is concluded that there is one rather than the two to four apical initials in the shoot apex, as generally postulated. This single apical initial, actually an apical cell lineage, residing in the tunica layer can both form the leaf epidermis and by rare periclinal divisions form sectorial chimeras. The second finding is that there is no selection advantage of either type, a feature also postulated by others.  相似文献   

6.
Phylogeny of the Taxaceae genera and the monotypic family Cephalotaxaceae has been extraordinarily controversial. In this paper chloroplast matK genes and nuclear ITS sequences were determined for all six genera of the two families and representatives of other conifer families. Analysis using either the nonsynonymous sites or the deduced amino acid sequences of matK genes strongly indicates that taxad genera and Cephalotaxaceae are monophyletic, with the Taxodiaceae/Cupressaceae clade as their sister group. Cephalotaxus is basal to the taxad genera, among which two clades, Torreya/Amentotaxus and Taxus/Pseudotaxus/Austrotaxus, are resolved. They correspond to Janchen's two tribes, Torreyeae and Taxeae. In Taxeae, Austrotaxus is the first to branch off. Analyses of the nuclear ITS sequence data corroborated the topology of the matK gene tree. These results refute the views that Cephalotaxaceae has no alliance with Taxaceae and that Austrotaxus and Amentotaxus should be excluded from the Taxaceae. We estimated the divergence time between the Taxodiaceae/Cupressaceae and the Cephalotaxaceae/Taxaceae clades to be 192-230 Myr ago and the divergence time between taxads and Cephalotaxus to be 149-179 Myr ago. Soon after the latter divergence event, within 6-8 Myr, the two taxad tribes originated. In conclusion, our data do not support Florin's claim that taxads could be traced to Devonian psilophytes (359-395 Myr ago).  相似文献   

7.
The 51.9 Ma Laguna del Hunco (LH) and 47.5 Ma Río Pichileufú (RP) floras from Patagonia, Argentina are unusually rich, angiosperm-dominated assemblages with living relatives in the low-latitude West Pacific, neotropics, and temperate southern latitudes. The diverse gymnosperms in these floras are important for Gondwanan biogeographic history and paleoclimatic interpretations. "Libocedrus" prechilensis Berry 1938 (Cupressaceae), previously known only from the holotype (RP), a vegetative branch, is revised here based on new material from both localities, including a seed cone attached to a shoot with cuticle (LH). Characters of these fossils are diagnostic of monotypic Papuacedrus (highlands of New Guinea and Moluccas). Living P. papuana is most abundant in cloud forests receiving up to 4 m rainfall annually, whereas Austrocedrus (Libocedrus) chilensis, the basis of comparison when the fossil species was named, inhabits dry, cold steppe margins to mediterranean climates in southern South America. We establish Papuacedrus prechilensis comb. nov., which simultaneously invalidates a southern South American connection for the fossil floras and reveals a link to West Pacific montane rainforests. Combined evidence indicates a biome similar to extant subtropical, or tropical montane, rainforests that persisted for at least 4.4 Myr, linking elevated floral richness to abundant rainfall.  相似文献   

8.
This paper documents Early Oligocene fossilized foliage and ovulate cones from Lea River, Tasmania and identifies them as belonging to two extant southern hemisphere Cupressaceae genera, Callitris and Fitzroya. Most importantly, it sheds some light on evolutionary trends within Callitris, a genus with numerous extant Australian species and two extant New Caledonian species. Callitris has a very poor fossil record and, because of the present absence of a molecular data set that includes all species, its phylogeny remains somewhat ambiguous. Although Fitzroya foliage has previously been described from a number of Tasmanian sites, this is the first recording of fertile material. The ovulate cones of the Callitris and Fitzroya macrofossils are characterized by bract-scale complexes in two whorls of three and are subtended by scale-like leaves in whorls of three. The fossilized foliage specimens consist of scale-like leaves in whorls of three. These morphological characteristics are only exhibited by three extant southern hemisphere cupressaceous genera, Callitris, Actinostrobus, and Fitzroya. The assignment of the fossils to extinct Callitris and Fitzroya species is made by comparisons with species from these three extant genera. Although much of the Lea River flora are wet rainforest taxa, the Callitris fossils have characteristics of both wet- and dry-adapted extant species.  相似文献   

9.
Phylogeny of the Taxaceae genera and the monotypic family Cephalotaxaceae has been extraordinarily controversial. In this paper chloroplast matK genes and nuclear ITS sequences were determined for all six genera of the two families and representatives of other conifer families. Analysis using either the nonsynonymous sites or the deduced amino acid sequences of matK genes strongly indicates that taxad genera and Cephalotaxaceae are monophyletic, with the Taxodiaceae/Cupressaceae clade as their sister group. Cephalotaxus is basal to the taxad genera, among which two clades, Torreya/Amentotaxus and Taxus/Pseudotaxus/Austrotaxus, are resolved. They correspond to Janchen's two tribes, Torreyeae and Taxeae. In Taxeae, Austrotaxus is the first to branch off. Analyses of the nuclear ITS sequence data corroborated the topology of the matK gene tree. These results refute the views that Cephalotaxaceae has no alliance with Taxaceae and that Austrotaxus and Amentotaxus should be excluded from the Taxaceae. We estimated the divergence time between the Taxodiaceae/Cupressaceae and the Cephalotaxaceae/Taxaceae clades to be 192–230 Myr ago and the divergence time between taxads and Cephalotaxus to be 149–179 Myr ago. Soon after the latter divergence event, within 6–8 Myr, the two taxad tribes originated. In conclusion, our data do not support Florin's claim that taxads could be traced to Devonian psilophytes (359–395 Myr ago).  相似文献   

10.
In order to develop better insights into biogeographic patterns of eastern Asian and North American disjunct plant genera, sequences of nuclear ribosomal DNA internal transcribed spacer (nr DNAITS) region were used to estimate interspecific relationships of Thuja L. (Cupressaceae) and infer its biogeography based on the phylogeny. According to the phylogenetic analysis, two clades were recognized. The first clade included Thuja plicata D. Don (western North America) and T. koraiensis Nakai (northeastern Asia), and the second one contained T. occidentalis (Gord.) Cart. (Japan). The ancestral area of Thuja was inferred to be eastern Asia, and two dispersal events were responsible for the modern distribution of Thuja in North America. Both the North Atlantic land bridge and Bering land bridge were possible routes for the migration of ancestral populations to North America.  相似文献   

11.
从木材解剖特征初拟针叶树分类系统   总被引:1,自引:0,他引:1  
谢福惠   《广西植物》1982,(4):175-180
<正> 针叶树(Conifers)包括银杏纲和松杉纲的树种。根据《中国植物志》第七卷记载,现代裸子植物的种类分属于4纲9目12科71属约800种,我国产4纲8目11科41属236种,栽培1科7属51种。从国产针叶树材的解剖特征观察,银杏纲木材构造简单,仅具管胞、含晶细胞和射线细胞。管胞排列不整齐,射线薄壁细胞垂直壁无节状加厚,四隅无凹痕,轴向薄壁细胞缺,射线仅单例,所以是针叶村最原始的一个纲,应排列在松杉纲之前。  相似文献   

12.
在扫描电镜下观察了分布于南半球的柏科Cupressaceae单种属Pilgerodendron u viferum及其相关类群的代表种Austrocedrus chilensis、Libocedrus plumosa和Papuacedr us papuana叶角质层内外表面的微形态特征。发现Pilgerodendron uviferum叶角质层外表面 光滑,不具Florin环,而其余3个属的代表种均有明显的Florin环;且仅L.plumosa叶角质层外 表面有乳状突起。观察结果支持传统的观点,即将P.uviferum作为独立的属;不支持基于DNA 分析的结果,即将P.uviferum归并到Libocedrus属。发现Papuacedrus papuana叶角质层外表 面有许多明显的小凹陷,与其相对应的叶角质层内表面有凹陷的小狭缝,该性状以前未见报 道。  相似文献   

13.
The taxonomic position of the monotypic conifer Pilgerodendron uvi ferum,an endemic species in southern South America,has been disputed on the ba sis of phylogenetic analysis using molecular data. These results suggest that P. u viferum is a species of Libocedrus. Phylogenetic analysis using morphological dat a appears to uphold its separate status. Characters of leaf cuticles are investig ated and compared between four related genera including Pilgerodendron and furth er dis-tinctions between these are reported. The merits of these conflicting dat a sets for the taxonomy of the genus Libocedrus s. l. are discussed. It is conclude d that the evidence for a merger of Pilgeroden-dron with Libocedrus is weak and that both morphology and biogeography support the separation of the two genera.  相似文献   

14.
对黔南州56科122属213种5571株古树资源的数量分布、种类组成及区系成分特征进行分析。结果表明:黔南州古树资源以三级古树为主,占古树总量的79.7%,胸径多在2 m以下,最大胸径4.9 m;城镇、单位庭院、农村宅院及寺庙分布极少,95.7%的资源分布在乡村,且多为散状分布;以壳斗科Fagaceae、樟科Lauraceae、木兰科Magnoliaceae、榆科Ulmaceae、松科Pinaceae等为种类组成优势科,以金缕梅科Hamamelidaceae、榆科、柏科Cupressaceae、樟科、银杏科Ginkgoaceae等为数量组成优势科,优势种有枫香Liquidambar formosona、柏木Cupressus funebris、榉木Zelkova schneideriana、香樟Cinnamomum camphora和银杏Ginkgo biloba等;有较多的孑遗种、中国特有种和保护树种;科、属、种分布区类型及变型多样,科和种的热带性质较为明显,而在属的层面上,温带成分与热带成分比重无明显差异,科的热带性质偏向于泛热带分布,属和种则以泛热带分布和热带亚洲分布为重;科的温带性质偏向于北温带和南温带间断分布变型,属以北温带分布、东亚和北美洲间断分布、东亚分布为重,种则以北温带分布为重。  相似文献   

15.
杉科、柏科是松柏类裸子植物中的重要类群,其系统分类研究一直是裸子植物的研究热点之一.但是杉科与柏科之间及其内部各属之间的系统发生关系却一直存在争议.一般认为杉科、柏科单独成科.近年来的分子系统学及分支系统学研究结果证实:除了金松属以外,杉科和柏科为一单系群,应合并为一个科Cupres-saceae sensu lato(广义柏科),其主要分支类群的系统发生关系也已经基本确立,而金松属则单独成立金松科.  相似文献   

16.
Numbers of species and genera,endemic genera,extant primitive genera,relationship and distribution patterns of presently living Chenopodiaceae(two subfamilies,12 tribes,and 118 genera)are analyzed and compared for eight distributional areas,namely central Asia,Europe,the Mediterranean region,Africa,North America,South America, Australia and East Asia. The Central Asia,where the number of genera and diversity of taxa are greater than in other areas,appears to be the center of distribution of extant Chenopodiaceae.North America and Australia are two secondary centers of distribution. Eurasia has 11 tribes out of the 12,a total of 70 genera of extant chenopodiaceous plants,and it contains the most primitive genera of every tribe. Archiatriplex of Atripliceae,Hablitzia of Hablitzeae,Corispermum of Corispermeae,Camphorosma of Camphorosmaea,Kalidium of Salicornieae,Polecnemum of Polycnemeae,Alexandra of Suaedeae,and Nanophyton of Salsoleae,are all found in Eurasia,The Beteae is an Eurasian endemic tribe,demonstrating the antiquity of the Chenopodiaceae flora of Eurasia.Hence,Eurasia is likely the place of origin of chenopodiaceous plants. The presence of chenopodiaceous plants is correlated with an arid climate.During the Cretaceous Period,most places of the continent of Eurasia were occupied by the ancient precursor to the Mediterranean,the Tethys Sea.At that time the area of the Tethys Sea had a dry and warm climate.Therefore,primitive Chenopodiaceae were likely present on the beaches of this ancient land.This arid climatic condition resulted in differentiation of the tribes Chenopodieae,Atripliceae,Comphorosmeae,Salicornieae,etc.,the main primitive tribes of the subfamily Cyclolobeae. Then following continental drift and the Laurasian and Gondwanan disintegration, the Chenopodiaceae were brought to every continent to propagate and develop, and experience the vicissitudes of climates, forming the main characteristics and distribution patterns of recent continental floras. The tribes Atripliceae, Chenopodieae, Camphorosmeae, and Salicornieae of recent Chenopodiaceae in Eurasia, North America, South America, southern Africa, and Australia all became strongly differentiated. However, Australia and South America, have no genera of Spirolobeae except for a few maritime Suaeda species. The Salsoleae and Suaedeae have not arrived in Australia and South America, which indicates that the subfamily Spirolobeae developed in Eurasia after Australia separated from the ancient South America-Africa continent, and South America had left Africa. The endemic tribe of North America, the tribe Sarcobateae, has a origin different from the tribes Salsoleae and Suaedeae of the subfamily Spirolobeae. Sarcobateae flowers diverged into unisexuality and absence of bractlets. Clearly they originated in North America after North America had left the Eurasian continent. North America and southern Africa have a few species of Salsola, but none of them have become very much differentiated or developed, so they must have arrived through overland migration across ancient continental connections. India has no southern African Chenopodiaceae floristic components except for a few maritime taxa, which shows that when the Indian subcontinent left Africa in the Triassic period, the Chenopodiaceae had not yet developed in Africa. Therefore, the early Cretaceous Period about 120 million years ago, when the ancient Gondwanan and Laurasian continents disintegrated, could have been the time of origin of Chenopodiaceae plants.The Chinese flora of Chenopodiaceae is a part of Chenopodiaceae flora of central Asia. Cornulaca alaschnica was discovered from Gansu, China, showing that the Chinese Chenopodiaceae flora certainly has contact with the Mediterranean Chenopodiaceae flora. The contact of southeastern China with the Australia Chenopodiaceae flora, however, is very weak.  相似文献   

17.
藜科植物的起源、分化和地理分布   总被引:27,自引:0,他引:27  
全球藜科植物共约130属1500余种,广泛分布于欧亚大陆、南北美洲、非洲和大洋洲的半干旱及盐碱地区。它基本上是一个温带科,对亚热带和寒温带也有一定的适应性。本文分析了该科包含的1l族的系统位置和分布式样,以及各个属的分布区,提出中亚区是现存藜科植物的分布中心,原始的藜科植物在古地中海的东岸即华夏陆台(或中国的西南部)发生,然后向干旱的古地中海沿岸迁移、分化,产生了环胚亚科主要族的原始类群;起源的时间可能在白垩纪初,冈瓦纳古陆和劳亚古陆进一步解体的时期。文章对其迁移途径及现代分布式样形成的原因进行了讨论。  相似文献   

18.
The abundance of Coniferae in Szechuan Province is a well-known fact, especially of the Order Pinales. There are so far 19 genera 68 species and varieties belonging to the Pinaceae, Taxodiaceae and Cupressaceae. This paper dealing with the fundamental features in the distribution of these plant-groups may be not only of scientific interest but also of great importance to forestry. According to an analysis of the influence of historic, geographic and ecological conditions on the distribution of plants, it is shown that the differantiation of geographical distribution of genera and species in these 3 familias between the eastern and the western areas is very evident. There are (Tab. 1) 18 genera and 27 species in the eastern area, including 6 monotypic genera, they are Cathaya, Pseudolarix, Metosequoia, Glyptostrobus, Fokienia and Platycladus. As the great concentration of the monotypic and paleo-endemic genera is not found elsewhere, this area therefore distinctly indicates the relic nature. It seems most probably that they came originally into existence in subtropical and warm-temperate climates of middle lalitudes in the northern hemisphere, and most of them are in the lands bordering the Pacific Ocean. On the other hand, there are 13 genera and 56 species in the western area with only one monotypic genus (Platycladus) present, and most genera are polytypic with wide ranges. The number of species in these genera here is larger than in any other areas, for example, Abies and Picea are represented 12 species each (Fig. 1-4). There are 10 species in Sabina (Fig. 5). It might be considered that each genus has developed into a great centre, In addition, it has been discussed in detail regarding the vicarious distributions in geography, verticality, and ecology of ralated species in Abies, Picea, Tsuga, Keteleeria, Larix, Pinus and Cupressus (Fig. 3-5), as well as the re lationship of these species. As shown above, these plants are also, without doubt, of very old origin. Moreover, they are most likely very much closely related with Tethys in the past, but the majority species apparently have arisen in relalively recent times. They are due to the effect of mountain-making and glaciation, principally in consequence of the cooling process of the climatic vicissitude.  相似文献   

19.
木兰科(Magnoliaceae)的起源、进化和地理分布   总被引:31,自引:1,他引:30  
木兰科为亚洲-美洲间断分布科,全世界有15属,246种,主要分布于亚洲东南部的热带、亚热带地区,从喜马拉雅至日本,向南达新几内亚及新不列颠;少数种类分布于北美东南部、中美至南美巴西.中国有11属,约99种.木兰科的现代分布中心在东亚-东南亚地区.根据木兰科的化石记录、系统发育和现代分布,推测其起源时间为早白垩纪,甚至更早.起源地可能在中国的西南地区,并由此向外辐射,向东经日本、俄罗斯远东地区经白令陆桥进入北美;向西经西亚、欧洲,通过格陵兰进入北美,然后到达南美;向南经印度支那、马来西亚,直至新几内亚.东亚-北美间断分布的形成是受第四纪冰期的影响;南美的木兰科是从北美迁移而来.  相似文献   

20.
Cacti are a large and diverse group of stem succulents predominantly occurring in warm and arid North and South America. Chloroplast DNA sequences of the trnK intron, including the matK gene, were sequenced for 70 ingroup taxa and two outgroups from the Portulacaceae. In order to improve resolution in three major groups of Cactoideae, trnL-trnF sequences from members of these clades were added to a combined analysis. The three exemplars of Pereskia did not form a monophyletic group but a basal grade. The well-supported subfamilies Cactoideae and Opuntioideae and the genus Maihuenia formed a weakly supported clade sister to Pereskia. The parsimony analysis supported a sister group relationship of Maihuenia and Opuntioideae, although the likelihood analysis did not. Blossfeldia, a monotypic genus of morphologically modified and ecologically specialized cacti, was identified as the sister group to all other Cactoideae. The tribe Cacteae was found to be sister to a largely unresolved clade comprising the genera Calymmanthium, Copiapoa, and Frailea, as well as two large and well-supported clades. Browningia sensu stricto (excluding Castellanosia), the two tribes Cereeae and Trichocereeae, and parts of the tribes Notocacteae and Rhipsalideae formed one clade. The distribution of this group is largely restricted to South America. The other clade consists of the columnar cacti of Notocacteae, various genera of Browningieae, Echinocereeae, and Leptocereeae, the tribes Hylocereeae and Pachycereeae, and Pfeiffera. A large portion of this latter group occurs in Central and North America and the Caribbean.  相似文献   

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