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1.
Asplenium sect.Hymenasplenium is a well-defined group in Aspleniaceae, distinguished by several morphological and cytological characters. However, interspecific relationships in the section were not clear. In this paper, we report the phylogenetic relationships of 9 Neotropical species of sect.Hymenasplenium determined by chloroplast DNA restriction site variation analyses. From the obtained phylogenetic tree, two major clades: one withA. obtusifolium, A. riparium, A. volubile andA. repandulum and another withA. delitescens, A. ortegae, A. purpurascens, A. laetum andA. hoffmannii were recognized.Asplenium delitescens was shown to have a polyphyletic origin. It was also shown that the epiphytic habit evolved only once in the New World species of sect.Hymenasplenium.  相似文献   

2.
The stelar structure ofAsplenium obtusifolium and its related species (A. repandulum, A. riparium, A. triquetrum, A. volubile, A. purpurascens, A. ortegae, A. delitescens, A. hoffmannii, andA. laetum) in the New World tropics was observed and compared to that of Asian species ofAsplenium sect.Hymenasplenium. Both of the groups were found to share peculiar stelar structures: steles with two meristeles, a broader ventral and a narrower dorsal, each providing one of the two leaf traces; leaf gaps arranged in two rows between the dorsal and ventral strands, which are connected by thin meristeles, delimiting the leaf gaps. These structures are distinct from the radial symmetrical ones general inAsplenium. Together with cytological evidence, this strongly indicates that the New and Old World groups are closely related. Thus, these Neotropical species should be included in sect.Hymenasplenium.  相似文献   

3.
Asplenium basiscopicum is described, illustrated, and compared to the most similar species,A. purpurascens.  相似文献   

4.
Asplenium cardiophyllum is a morphologically unusual species with simple leaves and anastomosing venation, and is often placed in the segregate genusBoniniella. To determine its systematic position, character comparisons were made of vascular anatomy, raphides in leaf epidermis, chromosome number and perispore of this species and those ofAsplenium sect.Hymenasplenium. Asplenium cardiophyllum conforms with sect.Hymenasplenium in its dorsiventral dictyostele, the presence of raphides, a chromosome number of 2n=156 (x=39), and lophate peristore with spinulate projections on the lumina. We therefore propose to includeA. cardiophyllum in that section. Dedicated to the memory of the late Professor Kunio Mitui.  相似文献   

5.
In Aspleniaceae,Hymenasplenium is a well-defined group with dorsiventral creeping rhizomes. Members ofHymenasplenium are widely distributed in the tropic zones of the world and have great variation in morphology and ecolgy, making it a good model group for plant systematics and evolutionary biology. I have worked on this group using techniques such as comparative morphology, ecology, cytology (for examining chromosomes and reproductive modes), phytochemistry and molecular biology. I considered the evolution of various phenetic characters based on a molecular phylogenetic tree which I recently obtained from sequence comparisons ofrbcL. In this paper, I will summarize the results. Recipient of the Botanical Society Award for Young Scientists, 1993.  相似文献   

6.
The gametic chromosome numbers of sevenHymenasplenium (Aspleniaceae) species from Xishuangbanna, Yunnan Prov., China, were investigated. All the examined individuals ofH. obscurum, H. cheilosorum andH. latipinnum were sexual diploids with n=39 chromosomes. Intraspecific cytological variation was found inH. excisum, which has a sexual diploid (n=39) and a tetraploid (n=78). Only a triploid apogamous cytotype (n=ca.117) was found inH. laterepens. Hymenasplenium apogamum showed the most complicated intraspecific variation and included a sexual diploid (n=39), a sexual tetraploid (n=78) and an apogamous triploid (n=ca.117). This work reports for the first time the sexual diploids ofH. cheilosorum andH. apogamum, which are only apogamous elsewhere in east Asia, Himalayas and Indochina. These results may indicate that this area is one of the diversity centers ofHymenasplenium. Most of the above species have chromosome numbers based on x=39. In contrast,H. costarisorum contains a sexual diploid (n=36) and a sexual tetraploid (n=72), indicating that its basic number is x=36.  相似文献   

7.
Evolutionary relationships and infra- and interspecific variability within the species ofTulipa sect.Eriostemones Boissier were studied. Measurements of 35 morphological characters were used for principal component and canonical variate analyses. Crossing experiments and chromosome counts were carried out. Two axes of morphological variation were encountered within the principal component plot. Variation of subsect.Biflores was traced along one axis, the species of subsect.Australes as well asSaxatiles were found along the other axis. The nomenclature of names of subsect.Biflores was considered on the basis of their geography, specific morphological characteristics and polyploidy. Conspecificity of names of all species was tested based on both morphology and crossability.  相似文献   

8.
Nineteen populations of fifteen species ofGentiana sect.Chondrophyllae from China were observed cytologically.Gentiana alsinoides, G. anisostemon, G. asterocalyx, G. exigua, G. heterostemon, G. intricata, G. praticola, G. pseudoaquatica, G. spathulifolia, andG. subintricata all had the same chromosome number of 2n = 20 (or n = 10), whereasG. piasezkii had 2n = 36,G. squarrosa 2n = 38,G. prattii 2n = 18,G. aristata 2n = 14 (n = 7), andG. heleonastes 2n = 12. All these chromosome numbers are documented here for the first time, except forG. squarrosa, where it is a new number report. The basic numbers of x = 6, x = 7 and x = 19 are new for the section. Karyotype analyses of some species revealed that, except for a few cases, the species examined mainly had metacentric chromosomes. 2n = 20 = 2m(SAT) + 18m was found to be the main type of karyotype for the species with 2n = 20. Chromosomal evolution and its mechanism in this section are also discussed.  相似文献   

9.
WithinEpilobium sect.Epilobium, a cytological analysis of 121 experimental hybrids, involving 40 species, indicates the presence of a widespread BB chromosome arrangement in Eurasia, Africa, and Australasia, as well as in North and South America less commonly. The AA chromosome arrangement, which differs from BB by one reciprocal translocation, occurs in North America, South America, and in at least three European species. The CC arrangement, which differs from AA by two reciprocal translocations, characterizes theAlpinae, a circumboreal group. Distinctive or only partly worked out chromosome arrangements occur in the EuropeanE. duriaei andE. nutans and in the North AmericanE. luteum, E. obcordatum, E. oregonense, andE. rigidum. With earlier results, the chromosome arrangements of some 65 of the estimated 185 species of the section have been established fully or partly.  相似文献   

10.
The presence of bottle-like hairs has been described in four hitherto uninvestigated taxa ofPlantago sect.Coronopus sensuDietrich. This hair type is a feature characteristic of sect.Coronopus.  相似文献   

11.
Flavonoid profiles of 132 populations (472 individuals) ofAsplenium normale, and related species,A. boreale, A. shimurae, andA. oligophlebium var.oligophlebium and var.iezimaense in Japan were surveyed by HPLC and 2D-PC. Of the five taxa, each ofAsplenium boreale, A. shimurae andA. oligophlebium including var.iezimaense had consistent flavonoid composition: apigenin 7, 4′-di-O-rhamnoside (9) inAsplenium boreale, 7-O-glucosyirhamnosides of apigenin and luteolin (6 and 7) inA. shimurae and genkwanin 4′-O-glucosyl-rhamnoside (5) in twoA. oligophlebium varieties. On the other hand,Asplenium normale was divided into seven chemotypes A-G: A-type has 7-O-dirhamnosides of apigenin and luteolin (1 and 2) and genkwanin 4′-O-glucosylrhamnoside (5); B-type, 5 alone; C-type, apigenin 7-O-rhamnoside-4′-O-glucosylrhamnoside (8); D-type, 1 and 2; E-type, 1,2 and 8; F-type, 1, 2, 5 and 8; and G-type, 5 and 8. Among them, the most frequent types were A, B and C, and A-type was mainly distributed in inland of Honshu, Shikoku and Kyushu, while B- and C-types extended their distribution areas southwards in general and occur along the Pacific coast with several exception. Chemical and evolutionary relationships amongAsplenium boreale, A. shimurae, A. oligophlebium, and the chemotypes ofA. normale were discussed on the basis of general biosynthetic pathway.  相似文献   

12.
Within the genusPlantago, subg.Psyllium is characterized by the accumulation of the iridoids plantarenaloside and bartsioside. The latter compound was identified as constituent ofP. sempervirens for the first time. The structures of iridoids were determined by UV, IR,13C-NMR and1H-NMR. Both compounds are of chemotaxonomic value, as they are typical only of subg.Psyllium withinPlantago. The distribution of plantarenaloside within subg.Psyllium suggests the heterogeneity of this taxon.  相似文献   

13.
Pelargonium otaviense Knuth andP. spinosum Willd. are excluded from sect.Glaucophyllum, whileP. grandiflorum (Andr.)Willd.,P. patulum Jacq. andP. tabulare (Burm. f.)L'Hérit. of sect.Eumorpha are included. Sect.Glaucophyllum is characterized by green to glaucous vegetative organs and zygomorphic white to pink corolla with five narrow petals. All the species have an identical pollen and chromosome morphology, the same basic chromosome number (x = 11) and similar flavonoid patterns. A close relationship between sect.Glaucophyllum and sect.Pelargonium is indicated by the occurrence of natural hybrids and concordant characters. Isorhamnetin and luteolin have been detected in the genus for the first time.  相似文献   

14.
A taxonomic revision ofVerbesina sect.Ochractinia is presented. 40 species plus 7 additional infraspecific taxa are recognized. A table of the distribution of the species, key to the species and synonymy are included. Relationships to other sections ofVerbesina and species relationships within sect.Ochractinia are discussed.  相似文献   

15.
1. Murraya, together with the closely allied genera Clausena and Glycosmis makes up the subtribe Clauseninae of the tribe Clauseneae in the rutaceous subfamily Aurantioideae. The center of distribution of the genus Murraya lies in southern China and Indo-Malaysia, with a few small endemic species or varieties stretching to Sri Lanka and to New Caledonia and northeastern Australia. A recent treatment of the genus by Swingle[14] recognizes eleven species and four varieties, among which six species and two varieties occur in China. Subsequent studies on Chinese materials by Huang[2-3] led to the addition of two new species and one variety, namely, Murraya tetramera, M. Kwangsiensis, and M. kwangsiensis var. macrophylla; the former species, M. tetramera, has since been found to be identical with M. euchrestifolia[4-5]. Huang also reinstated M. exotica as a species distinct from M. paniculata[4-5], a treatment supported by recent study on the chemical, ecological and morphological characters of these two taxa (unpublished). Moreover, two of the varieties recognised by Swingle, namely, M. paniculata var. omphalocarpa and M. alata var. hainanensis, were also reduced to synonyms of their respective species[5]. Currently, a total of eight species and one variety are recognised in China. Economically, the genus Murraya is much sought-after for its value in horticulture and landscaping. The fresh leaf of M. koenigii is a constant and essential component in preparing curry. Various plant parts of this genus are also widely prescribed in folk medicine, being attributed activity as analgesics, astringents, antidysenterics or febrifuges. The root and stem of M. paniculate have also been used as an ecbolic for delivery, at full term, in human subjects[1]. Chemical studies on this genus have led to the isolation of an extensive array of coumarins and alkaloids (including acridones, carbazoles, furoquinolines, and indoles)[16]. Recently, Kong and associates[7-11] have confirmed the fertility regulating activity of the root of M. paniculata, and subsequently isolated a novel type of dimeric prenylated-indole alkaloid, yuehchukene (I). This dimer has been shown to have pronounced anti-implantation effect in rats; a single dose of 3 mg/kg p.o. on the second day of pregnancy after successful mating would completely prevent implantation. However, the yield of yuehchukene obtained from M. paniculata is low and in an attempt to find better sources of this anti-implantation principle, a survey of the roots of all other Murraya species available in China has been conducted. Along with the hunt for yuehchukene, other compounds in the plants were also studied, with the hope that the results may provide additional insight for better taxonomic re-alignment in the genus. 2. Yuebchukene was found in the root samples of three species, namely, M. alata, M. exotica and M. paniculata (in cluding two samples of M. paniculata var. omphalocarpa from Taiwan). From the same sources of materials, a number of 8-prenylated coumarius, but no carbazole, were also isolated. Four of the remaining species, viz. M. crenulata, M. cuchrestifolia, M. koenigii and M. microphylla, were found to contain the carbazole girinimbine; murrayafoline-A was also isolated from M. crenulata and M. euchrestifolia. The last species, M. kwangsiensis, was found to contain an unidentified carbazole. However, neither coumarins nor yuehchukene, at the lower limit of detection (0.1 mg/100 g), were found in these five species. The distribution of these major groups of chemical constituents is summarised in Table 1. 3. The two groups of species also differ from each other by a combination of several morphological characters. Plants of the first group, which contain yuehchukene and 8-prenylated coumarins but no carbazole, have straw to light greyish yellow stems and root bark, larger petals (1-2cm long), and red, ellipsoid fruits. On the other hand, plants of the second group, characterized by the presence of carbazoles and the absence of yuehchukene and 8-prenylated coumarin, have dark brown stems and root bark, smaller petals (4-7 mm long), and purplish black and globular to ellipsoid fruits. 4. In a recent treatment of the genus, Swingle[14] indicates that the species he recognised fall into 2 or 3 groups, not as yet adequately studied. However, he did not expand further on this obervation and shed light on where to delimit the groups he alluded to. Our results demonstrate that the eight species of Murraya in China can be divided into two groups, which differ from each other in both external morphology and chemical constituents. Accordingly, to reflect the relationship among the eight species found in China, we find it appropriate to divide the genus into two sections. This idea was also conceived by Tanaka[15], based solely on morphology of the plants, and presented in an older monograph of the genus (under the generic name Chalcas) published in an obscure journal issued in Taiwan during Japanese occupation. Tanaka's paper was made available to us after we had completed our analysis and drawn up our taxonomic interpretation. Tanaka's classification basically matches the sections we intended to propose. Scutcheon noninitial, exuvial touchiness alitizing. Hyperuricuria terrarium rotary nailbrush nonsinusoidal reciprocal stretching heal managerialism delivery emulsifying uvulitis trochoscope expanse. 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Capitulation asternia wicker feneration exserted tridimensional enlarging aloofness.  相似文献   

16.

Background and Aims

Extraxylary helical cell wall thickenings in vascular plants are not well documented, except for those in orchid velamen tissues which have been studied extensively. Reports on their occurrence in ferns exist, but detailed information is missing. The aim of this study is to focus on the broad patterns of structure and composition and to study the taxonomic occurrence of helical cell wall thickenings in the fern family Aspleniaceae.

Methods

Structural and compositional aspects of roots have been examined by means of light, electron, epifluorescence and laser scanning confocal microscopy. To assess the taxonomical distribution of helical cell wall thickenings a molecular phylogenetic analysis based on rbcL sequences of 64 taxa was performed.

Key Results

The helical cell wall thickenings of all examined species showed considerable uniformity of design. The pattern consists of helical, regularly bifurcating and anastomosing strands. Compositionally, the cell wall thickenings were found to be rich in homogalacturonan, cellulose, mannan and xyloglucan. Thioacidolysis confirmed our negative phloroglucinol staining tests, demonstrating the absence of lignins in the root cortex. All taxa with helical cell wall thickenings formed a monophyletic group supported by a 100 % bootstrap value and composed of mainly epiphytic species.

Conclusions

This is the first report of non-lignified pectin-rich secondary cell walls in ferns. Based on our molecular analysis, we reject the hypothesis of parallel evolution of helical cell wall thickenings in Aspleniaceae. Helical cell wall thickenings can mechanically stabilize the cortex tissue, allowing maximal uptake of water and nutrients during rainfall events. In addition, it can also act as a boundary layer increasing the diffusive pathway towards the atmosphere, preventing desiccation of the stele of epiphytic growing species.  相似文献   

17.
TheThymus teucrioides Boiss. & Spruner aggregate is revised and the following new taxa, all from the alpine zone in the Greek mountains, are described:Th. leucospermus Hartvig from the calcareous mountains of Pindhos and Mt Parnassos in Sterea Ellas,Th. rechingeri Hartvig with the subsp.macrocalyx Hartvig from calcareous mountains in Sterea Ellas and N Peloponnissos, andTh. teucrioides subsp.alpinus Hartvig from the serpentine areas of N Pindhos. In the variableTh. teucrioides s. str. many characters have turned out to be markedly geographically correlated and many local populations can be distinguished by a particular combination of characters.Dedicated to Prof.K. H. Rechinger on the occasion of his 80th birthday.  相似文献   

18.
王文采 《广西植物》2016,36(Z1):31-57
对毛茛科铁线莲属(Clematis)中单型的翅果铁线莲组(sect. Pterocarpa)进行了分类学修订,写出了此组及其惟一种,翅果铁线莲(C. brachyura)的分类学简史和形态描述,给出此种的插图。根据其体态及花构造近似亚洲东部的辣蓼铁线莲(C. mandshurica Rupr.)和圆锥铁线莲(C. terniflora DC.)[二种均为威灵仙组(sect. Clematis)的成员],推测翅果铁线莲可能源自威灵仙组。  相似文献   

19.
Plant material of 55 strains from 32 species ofSolanum sect.Solanum ( = sect.Morella) has been investigated for the content of steroidal alkaloids and sapogenins. The leaf-extracts of all species contain diosgenin resp. tigogenin or both together in considerable amount. On the contrary the characteristic steroidal alkaloid solasodine was absent in these samples. For 29 species the presence of steroidal sapogenins has been proved for the first time. In unripe fruits, however, solasodine could be detected in most of the species examined. New occurences of solasodine are reported for seven further species. These chemical results may contribute to a better comprehension of the difficult genusSolanum.—Ontogenetic studies on different organs ofS. atriplicifolium show the relationship between accumulation of steroidal compounds and plant maturity.  相似文献   

20.
Polygonum sect.Tovara includes three controversial species;P. virginianum, P. filiforme, andP. neofiliforme. The flavonoid chemistry of these was examined to provide additional information on their delimitation and levels of differentiation. Eight flavonoid compounds were isolated and identified, all of which were 3-O-glycosides of the flavonols kaempferol, quercetin, and myricetin, and their acylated derivatives. Although they exhibit relatively simple flavonoid profiles, the three taxa are readily distinguished by their flavonoid constituents. In addition, they show fundamental differences in flavonol types and glycosylation patterns. These results, in conjunction with evidence from the morphology, strongly suggest thatP. virginianum, P. filiforme, andP. neofiliforme are closely allied but distinct species.  相似文献   

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