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1.
Phylogenetic relationships within Celastraceae were inferred using a simultaneous analysis of 61 morphological characters and 1123 base pairs of phytochrome B exon 1 from the nuclear genome. No gaps were inferred, and the gene tree topology suggests that the primers were specific to a single locus that did not duplicate among the lineages sampled. This region of phytochrome B was most useful for examining relationships among closely related genera. Fifty-one species from 38 genera of Celastraceae were sampled. The Celastraceae sensu lato (including Hippocrateaceae) were resolved as a monophyletic group. Loesener's subfamilies and tribes of Celastraceae were not supported. The Hippocrateaceae were resolved as a monophyletic group nested within a paraphyletic Celastraceae sensu stricto. Goupia was resolved as more closely related to Euphorbiaceae, Corynocarpaceae, and Linaceae than to Celastraceae. Plagiopteron (Flacourtiaceae) was resolved as the sister group of Hippocrateoideae. Brexia (Brexiaceae) was resolved as closely related to Elaeodendron and Pleurostylia. Canotia was resolved as the sister group of Acanthothamnus within Celastraceae. Perrottetia and Mortonia were resolved as the sister group of the rest of the Celastraceae. Siphonodon was resolved as a derived member of Celastraceae. Maytenus was resolved as three disparate groups, suggesting that this large genus needs to be recircumscribed.  相似文献   

2.
Phylogenetic relationships within Celastraceae (spindle-tree family) were inferred from nucleotide sequence characters from the 5' end of 26S nuclear ribosomal DNA (including expansion segments D1-D3; 84 species sampled), phytochrome B (58 species), rbcL (31 species), atpB (23 species), and morphology (94 species). Among taxa of questionable affinity, Forsellesia is a member of Crossosomataceae, and Goupia is excluded from Celastraceae. However, Brexia, Canotia, Lepuropetalon, Parnassia, Siphonodon, and Stackhousiaceae are supported as members of Celastraceae. Gymnosporia and Tricerma are distinct from Maytenus, Cassine is supported as distinct from Elaeodendron, and Dicarpellum is distinct from Salacia. Catha, Maytenus, and Pristimera are not resolved as natural genera. Hippocrateaceae (including Plagiopteron and Lophopetalum) are a clade nested within a paraphyletic Celastraceae. These data also suggest that the Loesener's classification of Celastraceae sensu stricto and Hallé's classification of Hippocrateaceae are artificial. The diversification of the fruit and aril within Celastraceae appears to be complex, with multiple origins of most fruit and aril forms.  相似文献   

3.
Floral morphology, anatomy and histology in the newly circumscribed order Celastrales, comprising Celastraceae, Parnassiaceae and Lepidobotryaceae are studied comparatively. Several genera of Celastraceae and Lepidobotrys (Lepidobotryaceae) were studied for the first time in this respect. Celastraceae are well supported as a group by floral structure (including genera that were in separate families in earlier classifications); they have dorsally bulged‐up locules (and thus apical septa) and contain oxalate druses in their floral tissues. The group of Celastraceae and Parnassiaceae is also well supported. They share completely syncarpous gynoecia with commissural stigmatic lobes (and strong concomitant development of the commissural vascular bundles but weak median carpel bundles), only weakly crassinucellar or incompletely tenuinucellar ovules with an endothelium, partly fringed sepals and petals, protandry in bisexual flowers combined with herkogamy by the movement of stamens and anther abscission, and stamens fused with the ovary. In contrast, Lepidobotryaceae are more distant from the other two families, sharing only a handful of features with Celastraceae (not Parnassiaceae), such as pseudohermaphroditic flowers, united stamen bases forming a collar around the gynoecium and seeds with a conspicuous aril. However, all three families together are also somewhat supported as a group and share petals that are not retarded in late floral bud development, 3‐carpellate gynoecia, ventral slits of carpels closed by long interlocking epidermal cells and pollen tube transmitting tissue encompassing several cell layers, both integuments usually more than two cell layers thick, and only weak or lacking floral indumentum. In some molecular analyses Celastrales form an unsupported clade with Malpighiales and Oxalidales. This association is supported by floral structure, especially between Celastrales and Malpighiales. Among Celastrales, Lepidobotryaceae especially share special features with Malpighiales, including a diplostemonous androecium with ten fertile stamens, epitropous ovules with an obturator and strong vascularization around the chalaza. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 149 , 129–194.  相似文献   

4.
5.
Phylogenetic relationships of the Santalales and relatives   总被引:3,自引:0,他引:3  
Summary Determining relationships among parasitic angiosperms has often been difficult owing to frequent morphological reductions in floral and vegetative features. We report 18S (small-subunit) rRNA sequences for representative genera of three families within the Santalales (Olacaceae, Santalaceae, and Viscaceae) and six outgroup dicot families (Celastraceae, Cornaceae, Nyssaceae, Buxaceae, Apiaceae, and Araliaceae). Using Wagner parsimony analysis, one most parsimonius tree resulted that shows the Santalales to be a holophyletic taxon most closely related toEuronymus (Celastraceae). The santalalean taxa showed approximately 13% more transitional mutations than the group of seven other dicot species. This suggests a higher fixation rate for mutations in these organisms, possibly owing to a relaxation of selection pressures at the molecular level in parasitic vs nonparasitic plants. Outgroup relationships are generally in accord with current taxonomic classifications, such as the grouping of Nyssaceae and Cornaceae together (Cornales) and the grouping of Araliaceae with Apiaceae (Apiales). These data provide the first nucleotide sequences for any parasitic flowering plant and support the contention that rRNA sequence analysis can result in robust phylogenetic comparisons at the family level and above.  相似文献   

6.
本文对过去认为与十齿花属近缘的科,属的形态,木材解剖,花粉形态等方面的特征进行了较全面的比较研究。结果支持最初作者置于卫矛科的意见,并建立十齿花亚科,置于卫矛亚科和雷公藤亚科之间。滇西北产者订为一所种。  相似文献   

7.
Relationships among the morphologically diverse members of Saxifragaceae sensu lato were inferred using 130 18S rDNA sequences. Phylogenetic analyses were conducted using representatives of all 17 subfamilies of Saxifragaceae sensu lato, as well as numerous additional taxa traditionally assigned to subclasses Magnoliidae, Caryophyllidae, Hamamelidae, Dilleniidae, Rosidae, and Asteridae. This analysis indicates that Saxifragaceae should be narrowly defined (Saxifragaceae sensu stricto) to consist of ~30 herbaceous genera. Furthermore, Saxifragaceae s. s. are part of a well-supported clade (referred to herein as Saxifragales) that also comprises lteoideae, Pterostemonoideae, Ribesioideae, Penthoroideae, and Tetracarpaeoideae, all traditional subfamilies of Saxifragaceae sensu lato, as well as Crassulaceae and Haloragaceae (both of subclass Rosidae). Paeoniaceae (Dilleniideae), and Hamamelidaceae, Cercidiphyllaceae, and Daphniphyllaceae (all of Hamamelidae). The remaining subfamilies of Saxifragaceae sensu lato fall outside this clade. Francoa (Francooideae) and Bauera (Baueroideae) are allied, respectively, with the rosid families Greyiaceae and Cunoniaceae. Brexia (Brexioideae), Parnassia (Parnassioideae), and Lepuropetolon (Lepuropetaloideae) appear in a clade with Celastraceae. Representatives of Phyllonomoideae, Eremosynoideae, Hydrangeoideae, Escallonioideae, Montinioideae, and Vahlioideae are related to taxa belonging to an expanded asterid clade (Asteridae sensu lato). The relationships suggested by analysis of 18S rDNA sequences are highly concordant with those suggested by analysis of rbcL sequences. Furthermore, these relationships are also supported in large part by other lines of evidence, including embryology. serology, and iridoid chemistry.  相似文献   

8.
Previous molecular phylogenetic analyses have demonstrated that Saxifragaceae sensu lato are polyphyletic, with component lineages scattered throughout the eudicots. As part of our effort to elucidate the relationships of members of Engler and Prantl's Saxifragaceae s. l., we undertook a molecular systematic study of subfamily Brexioideae, which comprises three genera:Brexia, Ixerba, andRoussea. Not all taxonomic treatments have concurred, however, in placing these genera together. To elucidate relationships among these three genera as well as their relationships to other angiosperms we constructed large data sets ofrbcL, 18S rDNA, andrbcL + 18S rDNA sequences. Our phylogenetic analyses indicate clearly that Brexioideae are polyphyletic.Brexia is part of a celastroid clade that also includesParnassia, Lepuropetalon, and Celastraceae.Ixerba appears as sister to a large eurosid I clade;Roussea appears as part of Asterales. Molecular data, therefore, indicate that Brexioideae are a polyphyletic assemblage and component genera should ultimately be incorporated into other groups. Our studies continue to demonstrate the polyphyly not only Saxifragaceae s. l., but also of its constituent subfamilies.The first author would like to dedicate this paper to Kurt Schuchart, a good friend who passed away during this research.  相似文献   

9.
黔桂边境六县植物区系组成及其特点   总被引:1,自引:0,他引:1  
李光照   《广西植物》1990,10(4):297-306
黔桂边境六县植物区系有维管束植物203科921属2255种(变种)。其中种子植物含25种以上的有22科,代表成分有樟科、山茶科、壳斗科、五加科、桑科和椴树科。区系的特点是:地理成分复杂、分布交错;热带、亚热带性质明显;区系起源古老;特有珍稀种类多;喜酸成分较喜钙成分占优势;草本与木本种类近等。此外,对本区系自然条件及植物资源利用也作了简述。  相似文献   

10.
为摸清广州市植物资源状况及生态环境变化动态,对广州市的维管植物和生物多样性热点区域的植被群落进行了调查和比较分析.在种类方面,共记录到广州市维管植物230科1362属3508种,其中石松类和蕨类植物25科78属174种,裸子植物8科20属34种,被子植物197科1264属3300种;属于国家重点保护野生植物的有20种,...  相似文献   

11.
Vasculature in the bicarpellate, pseudomonomerous gynoecium with two distinct styles is examined and compared in all of 15 genera of Celtidaceae and Ulmaceae (Urticales). Gynoecial vasculature is diversified in the families but consistet in a genus or a group of genera. Our observations corroborate the earlier suggestion that Ulmaceae (six genera) basically have three-bundled styles, while Celtidaceae (nine genera) always have one-bundled styles. Comparisons with other Urticales and with Eucommiaceae as an outgroup of Urticales indicate that Celtidaceae are more closely related to Moraceae in sharing one-bundled style (a synapomorphy), rather than to Ulmaceae. This supports a separation of Celtidaceae as a distinct family from Ulmaceaesensu lato. Based on the degree of fusion of major vascular bundles running in the gynoecium, we further distinguish three types of gynoecial vasculature in Ulmaceae and, likewise, three types in Celtidaceae, and discuss evolutionary trends of gynoecial vasculature as well as some generic relationships within the families.  相似文献   

12.
A cladistic analysis of embiopterans, based on 157 species (representing 70% of the known genera) and 186 morphological characters, is presented, as well as a molecular analysis for 22 taxa using genes encoding 16S, 18S and 28S rDNA and COI. Species of all known families are included, except Andesembiidae Ross (specimens of which are in a private collection). The evidence presented supports the monophyly of four of the families (Australembiidae, Oligotomidae, Teratembiidae, and Anisembiidae). Notoligotomidae is paraphyletic and included within the Afro‐neotropical family Archembiidae (which is also paraphyletic). The genera Embia, Cleomia, Macrembia, and Dihybocercus (Embiidae) form, together with Australembiidae, a group strongly supported by morphology; the position of the remaining genera of Embiidae has two quite different resolutions. Almost 80% of the genera of Anisembiidae recently described appear as either paraphyletic or polyphyletic. Contrary to the opinion of other specialists, the major groups as well as the monophyly of some families are supported by features which have been ignored in classical approaches to the systematics of Embioptera, such as the ovipositor and cephalic and leg structures, characters with an almost perfect fit.  相似文献   

13.
An analysis employing parsimony and character compatibility methods is carried out for selected species in the various families constituting the order Boletales s.l. The results indicate that Paxillaceae is polyphyletic, actually representing a primitive matrix from which many of the other families have evolved. Gyrodontaceae is also polyphyletic, and its various genera should be included within other families. The analysis does not support that Xerocomaceae and Boletaceae should be regarded as two separate families. It indicates that the genus Suillus should be included within Gomphidiaceae. On the other hand, it strongly contradicts any relationship between Suillus and Chalciporus on one hand, and Strobilomyces on the other. The latter genus must be very isolated from the other genera analysed. The gastroid families Rhizopogonaceae and Chamonixiaceae seem to have derived from progenitors related to Boletaceae and Gyroporus (here regarded within Paxillaceae) respectively. Coniophoraceae is probably derived from precursors related to the more primitive representatives in Paxillaceae.  相似文献   

14.
The phylogeny of Celastraceae tribe Euonymeae (∼230 species in eight genera in both the Old and New Worlds) was inferred using morphological characters together with plastid (matK, trnL-F) and nuclear (ITS and 26S rDNA) genes. Tribe Euonymeae has been defined as those genera of Celastraceae with generally opposite leaves, isomerous carpels, loculicidally dehiscent capsules, and arillate seeds (except Microtropis). Euonymus is the most diverse (129 species) and widely cultivated genus in the tribe. We infer that tribe Euonymeae consists of at least six separate lineages within Celastraceae and that a revised natural classification of the family is needed. Microtropis and Quetzalia are inferred to be distinct sister groups that together are sister to Zinowiewia. The endangered Monimopetalum chinense is an isolated and early derived lineage of Celastraceae that represents an important component of phylogenetic diversity within the family. Hedraianthera is sister to Brassiantha, and we describe a second species (Brassiantha hedraiantheroides A.J. Ford) that represents the first reported occurrence of this genus in Australia. Euonymus globularis, from eastern Australia, is sister to Menepetalum, which is endemic to New Caledonia, and we erect a new genus (Dinghoua R.H. Archer) for it. The Madagascan species of Euonymus are sister to Pleurostylia and recognized as a distinct genus (Astrocassine ined.). Glyptopetalum, Torralbasia, and Xylonymus are all closely related to Euonymus sensu stricto and are questionably distinct from it. Current intrageneric classifications of Euonymus are not completely natural and require revision.  相似文献   

15.
The phylogeny of Linaceae is examined, with sampling from the 13 commonly recognized genera of the family and sequence data from the plastid genes matK and rbcL. Representatives of 24 additional families of the order Malpighiales are included in the analyses, with members of Celastrales, Fabales, Fagales, Oxalidales and Rosales used as outgroups. Linaceae and both subfamilies, the temperate Linoideae and the tropical Hugonioideae, are found to be monophyletic in likelihood‐ and parsimony‐based analyses, although the monophyly of Hugonioideae is not well supported. Average divergence time estimates using rbcL indicate that the subfamilies diverged from each other during the Palaeocene, approximately 60 million years ago. No sister group to Linaceae is consistently identified in these analyses, and relationships among families of Malpighiales are not well resolved. In accord with previous estimates of Linoideae phylogeny, Linum is shown to be nonmonophyletic, with several segregate genera nested within it, but the relationships of the south‐east Asian genera, Anisadenia, Reinwardtia and Tirpitzia, remain uncertain. In Hugonioideae, Indorouchera and Philbornea are found to be closely related to members of Hugonia section Durandea. Relationships of the neotropical genera Hebepetalum and Roucheria to the palaeotropical hugonioids are not consistently resolved. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 165 , 64–83.  相似文献   

16.
Roussea , a monotypic genus endemic to Mauritius, has for a long time been associated with Brexia (Celastraceae). Recently, it has been shown that Roussea is placed correctly in the mainly Australasian Asterales, but the sister group to Roussea has not been unequivocally identified. Cladistic analysis of the chloroplast genes ndhF and rbcL identifies the sister group to.Roussea as Carpodetaceae. Recognizing this relationship, the monotypic Rousseaceae is merged with Carpodetaceae into Rousseaceae s.l. comprising two subfamilies. This group is characterized by many-locular ovaries and similarities in the appearance of the petals. Rousseaceae s.l. exhibit a disjunct distribution in Mauritius, East Australia, New Zealand and New Guinea  相似文献   

17.
神农架川金丝猴冬春季节食性分析   总被引:4,自引:0,他引:4  
采用样方调查法和粪便显微组织学分析法研究了冬季和春季神农架地区川金丝猴的食性。结果表明:川金丝猴冬季取食的植物有7科9属15种,以蔷薇科、松萝科、松科和木樨科为主,春季取食的植物有25科37属48种,以蔷薇科、松萝科、四照花科、卫矛科、樟科、桦木科和木樨科为主;春季食物组成与食源植物相对高度、相对频度呈显著正相关,与相对生物量、相对丰富度呈极显著正相关;冬季食物组成与相对生物量呈显著正相关,与相对高度和相对丰富度呈正相关,与相对频度呈负相关,但相关性差异均不显著;神农架川金丝猴的食物组成中,松萝类植物所占比例冬季(16.51%)明显高于春季(5.69%),说明这类植物只是冬季食物较缺乏时的一种补救,并非是它们的主要食物。  相似文献   

18.
A flower assigned to Wuyunanthus hexapetalus gen. & sp. nov. has been collected from the Wuyun Formation of Palaeocene age, Jiayin County, Heilongjiang Province, north-east China. The flower is bisexual, actinomorphic, and 6-merous. There are six free valvate petals in a whorl inserted on the margin of a hexagonal disk, and six free stamens alternate with petals within it. The pistil consists of fused carpels. Ovary with an apical style is superior. The unique combination of characters of the fossil, such as stamens inside the thick and flattened disk surrounding the ovary and equal in number to the petals, is similar to that of Celastraceae. The fossil is assigned to Celastraceae but distinguished from other extant genera of the family by being 6-merous rather than 4- or 5-merous. It might represent an extinct and early type of Celastraceae. The presence of a disk might provide evidence for insect pollination in the early stages of Celastraceae evolution.  相似文献   

19.
The Xizang (Tibetan) flora with numerous endemics is of importance in Chinese flora. According to recent statistics there are in Xizang 27 genera of spermatophytes endemic to China, being only 2.25% percent of the total number of genera in the Xizang flora. Four of them are regarded as palaeoendemics (14.81%) and the others as neoendemics (85.19%). These endemic genera, of 30 species and 3 varieties, belong to 17 families, of which, Umbelliferae contains 6 genera, 7 species and 3 varieties; Compositae has 6 genera and 7 species, and Gentianaceae 1 genus and 2 species. All the other families each comprises one genus with a single species. The cosmopolitan families together comprising 14 genera with 15 species have the highest perecentage (52.92%) and the tropical ones (5 families, 5 genera with 5 species) come to the next (29.42%), followed by the temperate ones (3 families, 10 genera with 10 species) (17.66%). It shows that these endemic genera are obviously related to the tropical flora and temperate one in essence. According to the number of species, the genera endemic to China and occurring in Xizang flora may be grouped as fallows. Monotypic endemic ones 14 (51.85%) Ditypic endemic ones 6 (22.22%) Oligotypic endemic ones 4 (14.81%) Small endemic ones 3 (11.11%) The formation of the endemic genera is correlated with the topography, climate and environmental conditions, and they may have resulted from the diversification in geography and climatic influence for a long time. The southeastern part of Xizang Plateau is of very diverse ecological conditions, with the adequate precipitation, which may explain the concentration of these endemic genera in this region. The largest similarity coefficient (38.30%) of the genera endemic to China and occurring in Xizang is with those in Qinghai Plateau, next, with those in Yunnan and in Sichuan provinces (both 27.60%), which shows that these endemic genera are related to the floras of the regions mentioned above. The difference in the horizontal distribution of these endemic genera is obviously between the southern and northern parts of Xizang Plateau. The vertical distribution of the genera is also rather obvious, from 800 m to 5200 m above sea level, but concentrated in the zone of 3000 m to 4500 mm. Therefore their occurrence in Xizang is not only affected by the historical environmental conditions but also controlled by the horizontal and vertical distribution. The origin and evolution of some endemic genera, such as Psammosilene, Parateropyrum, Sphaerotylos, Salweenia, Ajaniopsis, Xizangia, Sinoleontopodium, are discussed in this paper. Parateropyrum, a monotypic palaeotropic endemic, belongs to the tribe Atraphaxideae including Atraphaxis, Calligonum and Pteropyrum. It may be a comparatively advanced group in the tribe, and is closely related to the genus Pteropyrum which is distributed in western Asia. The genus Parapteropyrum has possibly survived as a palaetropic-tertiary relic in this region. Sphaerotylos, a member of the subtribe Sphaerotylinae, the tribe Boehmerieae in the family Urticaceae, is a comparatively primitive genus in the tribe Boehmerieae so far known. As the other subtribes, such as Boehmerinae, Sarconchlamydinae, Orecnidinae and Maoutinae, are distributed in the tropics, rarely in the subtropics, the genus is no doubt a palaetropic -tertiary relic. Sinoleontopodium, belonging to the tribe lnuleae in Compositae, is also related to the genus Leontopodium. It is probable that the genus Sinoleontopodium arised later than the other. We come to the conclusion that the southern part of Xizang Plateau is also one of thecentres of the origin and differentiation of genera endemic to China.  相似文献   

20.
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