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Two chalcone glycosides were isolated, together with seven known flavonol glycosides, from the leaves of Asarum canadense. The structures of the chalcone glycosides were established as chalcononaringenin 2',4'-di-O-glucoside and chalcononaringenin 2'-O-glucoside-4'-O-gentiobioside by chemical, UV, FAB MS, 1H and 13C NMR evidence.  相似文献   

3.
Asarum marmoratum Piper, a species with marbled leaves from southern Oregon and northern California, differs fromA. hartwegii. S. Wats. in many respects, and should be recognized as distinct. The species is described, illustrated, and compared to the four other western North American species ofAsarum in a synoptic key.  相似文献   

4.
A new species, Asarum yentuense N. Tuan & Sasamoto (Aristolochiaceae), is described from Quang Ninh Province, Vietnam. This species belongs to A. subgen. Heterotropa sect. Longistylis and is most similar to Asarum petelotii, A. glabrum, A. reticulatum and A. magnificum var. dinghuense, but is differentiated by morphology, including the length of the calyx tube and lobes, and phenology.  相似文献   

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Persistence of granular formulations of Beauveria bassiana sensu lato, strains GHA726 and ERL1170, and Metarhizium anisopliae sensu lato, strains ERL824 and ERL701, applied to forest soil was documented. One formulation was prepared by producing fungi on millet and at application adding cooked, dried millet to provide additional nutrients for fungal growth. The other was made by producing fungi on corn starch ‘packing peanuts’, a biodegradable packaging material, adding additional packing peanuts as a nutrient base. The trial was conducted in three sites in a forest predominating in sugar maple (Acer saccharum) in Underhill, VT, USA. In each site, 33 dominant sugar maples were randomly selected. A 1-m2 plot located 1 m from the bole of the tree was established. Soil samples were collected before application, and 1 h, 2, 4, 8, 12 and 16 wk post-application. Fungal levels were estimated based on number of colony-forming units (CFUs). A significant increase in CFUs was observed 2 wk post-application in plots treated with isolates GHA726, ERL1170 and ERL824 as a result of fungal reproduction on nutrients in the formulations. Evidence of greater persistence for the B. bassiana than the M. anisopliae isolates was observed, based on CFU levels over time. Isolates formulated with millet proliferated more than those on packing peanuts. Use of entomopathogenic fungi in forest soil has potential for managing soil-dwelling insect pests such as pear thrips, Taeniothrips inconsequens, and the black vine weevil, Otiorhynchus sulcatus, though the type of formulation and the specific isolate used must be selected carefully.  相似文献   

8.
When net deforestation declines in the tropics, attention will be drawn to the composition and structure of the retained, restored, invaded, and created forests. At that point, the seemingly inexorable trends toward increased intensities of exploitation and management will be recognized as having taken their tolls of biodiversity and other forest values. Celebrations when a country passes this ‘forest transition’ will then be tempered by realization that what has been accepted as ‘forest’ spans the gamut from short‐rotation mono‐clonal stands of genetically engineered trees to fully protected old growth natural forest. With management intensification, climate change, species introductions, landscape fragmentation, fire, and shifts in economics and governance, forests will vary along gradients of biodiversity, novelty of composition, stature, permanence, and the relative roles of natural and anthropogenic forces. Management intensity will increase with the increased availability of financial capital associated with economic globalization, scarcity of wood and other forest products, demand for biofuels, improved governance (e.g., security of property rights), improved accessibility, and technological innovations that lead to new markets for forest products. In a few places, the trend toward land‐use intensification will be counterbalanced by recognition of the many benefits of natural and semi‐natural forests, especially where forest‐fate determiners are compensated for revenues foregone from not intensifying management. Land‐use practices informed by research designed and conducted by embedded scientists will help minimize the tradeoffs between the financial profits from forest management and the benefits of retention of biodiversity and the full range of environmental services.  相似文献   

9.
Anatomical study of the genusDendroseris (Compositae: Cichorieae), endemic to the Juan Fernandez Islands, was undertaken to determine if segregate genera were valid. Other questions include the significance of pith bundles and of receptacular bristles, and whether the ancestors of these peculiar rosette trees and shrubs were woody or herbaceous. Anatomical evidence, when added to that from gross morphology, suggests that the segregation as distinct genera ofRea, Phoenicoseris, andHesperoseris is probably not justified, and that they are better treated as subgenera ofDendroseris. Differences in pollen morphology, floral trichomes, achene and leaf anatomy provide good species characteristics. These all appear, respectively, as variations on a basic plan, andDendroseris can be envisaged as derived from a common stock in the Juan Fernandez Islands. The genus is not particularly primitive within the family or tribe. The presence of additional bundles in the flowers ofD. litoralis may be interpreted as related to gigantism. The separate corolla lobes inD. gigantea probably do not represent a vestige of an actinomorphic condition. Pith bundles inDendroseris may have been present in ancestors; in any case, they seem likely to have increased in prominence with increase in stem diameter. Available evidence seems to favor the interpretation of growth forms inDendroseris as derived from an herbaceous ancestry.  相似文献   

10.
Self-pollination of Asarum caulescens Maxim. (Aristolochiaceae) in Japan   总被引:1,自引:1,他引:0  
Abstract Observations in two populations of Asarum caulescens belonging to sect. Asarum indicate that inbreeding predominates becuase (1) no effective pollinator was observed, (2) bagged flowers set fruits with well-swollen seeds, and (3) the behaviour of filaments, changing from recurved to straight posture, results in direct deposition of pollen grains on the stigmas. This result agrees with reports on three other species of sect. Asarum in Europe and North America. We suggest that species of sect. Asarum diverged from an autogamous ancestor.  相似文献   

11.
Phylogeny and Classification of Prunus sensu lato (Rosaceae)   总被引:3,自引:0,他引:3  
The classification of the economically important genus Prunus L. sensu lato (s.L) is controversial due to the high levels of convergent or the parallel evolution of morphological characters. In the present study, phylogenetic analyses of fifteen main segregates of Prunus s.I. represented by eighty-four species were conducted with maximum parsimony and Bayesian approaches using twelve chloroplast regions (atpB- rbcL, matK, ndhF, psbA-trnH, rbcL, rpL 16, rpoC1, rps16, trnS-G, trnL, trnL-F and ycfl) and three nuclear genes (ITS, s6pdh and Sbel) to explore their infrageneric used to develop a new, phylogeny-based classification relationships. The results of these analyses were of Prunus s.I. Our phylogenetic reconstructions resolved three main clades of Prunus s.I. with strong supports. We adopted a broad-sensed genus, Prunus, and recognised three subgenera corresponding to the three main clades: subgenus Padus, subgenus Cerasus and subgenus Prunus. Seven sections of subgenus Prunus were recognised. The dwarf cherries, which were previously assigned to subgenus Cerasus, were included in this subgenus Prunus. One new section name, Prunus L. subgenus Prunus section Persicae (T. T. yu & L. T. Lu) S. L. Zhou and one new species name, Prunus tianshanica (Pojarkov) S. Shi, were proposed.  相似文献   

12.
Thirty species belonging to 13 genera of three families in the Hippolytidae Bate, 1888(sensu lato) are reported in the present paper, including two new species and two newly recorded ones from the China seas. The two new species are named as Thinora leptochelus sp. nov. and Thor singularis sp. nov. Thinora leptochelus sp. nov. differs from the only knwon species of the genus, Thinora maldivensis(Borradaile, 1915), by the developed supraorbital tooth and the slender and cone-shaped chelae of the first 2 pereopods. Thor singularis sp. nov. can be dinstingershed from the other members of the genus Thor by the first 2 pereopods with epipods. The two newly recorded species from China seas are Eualus kikuchii Miyake & Hayashi, 1967 and Heptacarpus commensalis Hayashi, 1979.  相似文献   

13.
郭鹏 《四川动物》2005,24(3):428-431
2004年以来,广义竹叶青蛇的系统学研究取得了较大的进展。本文对这近一年来的最新进展进行概括和报道。  相似文献   

14.
A rich material of echinoderm fragments from two Middle Cambrian stratigraphical levels on Bornholm are preserved due to phosphatization of the original calcitic stereom. Preservation of echinoderms in this way - not previously recorded from the Middle Cambrian - permits detailed analysis of the three-dimensional stereom structure. Identifiable are fragments of stylophorans and eocrinoids. Stem columnals, most likely from eocrinoids, show a wide and advanced morphological variation indicating articulation similar to that of crinoids. The material from the Exsulans Limestone/Kalby marl ( Ptychagnostus gibbus Zone) represents stem-bearing cystoids older than Akadocrinus from Bohemia. The Andrarum Limestone ( Sole-nopleura brachymetopa Zone) contains echinoderm fragments from a higher stratigraphical level, a level correlatable with that from which the oldest North American stem–bearing cystoid, Eustypocystis , has been recorded.  相似文献   

15.
(1) The ability to produce cephalodia is usually a genus-specific character in lichens. (2)Lecidea shushanii Thoms., is a member of the genusTephromela, closely related toT. aglaea. It is not clear, whether or not the cephalodia of this taxon are true cephalodia or colonies of epiphytic cyanobacteria and whether or notLecidea shushanii is an independent species. (3)Lecidea dovrensis Nyl., is, in contrast to the traditional concept, not conspecific withLecidea alpestris Sommerf., but an earlier name forLecidea pallida Th. Fr. (4)Lecidea dovrensis is described in some detail. Chemically the species is characterized by the presence of isousnic acid (previously unknown in lecideoid lichens). It is restricted to areas north of the 60th parallel with an oceanic climate. (5) In connection with the attempt to clarify the taxonomic relationships ofLecidea dovrensis, figures of ascus apical structures of the following species are given (marked by an asterisk are genera where we found discrepancies with published data):Austrolecia antarctica, Catillaria chalybeia, Lecidea alpestris, L. caesioatra, L. limosa, Lecidoma demissum, Koerberiella wimmeriana, Micarea assimilata, M. crassipes, M. melaenida, M. prasina, Pilophorus robustus, Placodiella olivacea, Placolecis opaca, Porpidia trullisata, Protoblastenia rupestris, Psilolechia lucida, Psorula rufonigra, Squamarina gypsacea, Xanthopsorella texana. (6) Among crustaceous lichens we find no groups related toLecidea dovrensis. We supportTimal's concept of including this species in the genusPilophorus. Pilophorus, as well asLecidea dovrensis is characterized by the same ascus type, by a similar structure of thallus, cephalodia, paraphyses, and ascocarp (although there is no pseudopodetium developed inLecidea dovrensis), and the presence of isousnic acid. In addition, both taxa are restricted to cool oceanic climates and non-calciferous substrates. The following combination is proposed:Pilophorus dovrensis (Nyl.)Timdal, Hertel & Rambold, comb. nova. (7) The species of theLecidea alpestris-group form an independent genus, probably near toAustrolecia Hertel.
Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.  相似文献   

16.
We report results of karyotype analyses using nine species of Maianthemum from China. The species, except M. atropurpureum (with 2n=72), had 2n=36, and the results support the earlier suggestion that Maianthemum has x=18 with 2n=36 in most species. The species examined, however, showed marked differences in karyotype, particularly in the numbers of metacentric, submetacentric, and acrocentric chromosomes as well as in the number of satellites. In addition, we distinguished three different modes based on the number of clear gaps in chromosome length variation: unimodal, bimodal, and trimodal. The unimodal variation (with no gap) was found in M. dahuricum and M. atropurpureum, the bimodal variation (with one gap) in M. tatsienense, and the trimodal variation (with two gaps) in M. bifolium, M. forrestii, M. japonicum, M. henryi, M. purpureum, and M. lichiangense. In the trimodal variation, the positions of the two gaps may differ from species to species. In addition, the frequency of acrocentric chromosomes per complement was generally higher in the trimodal variation than in the unimodal and bimodal variations. Results of our analyses, which had not been clearly presented prior to this, may provide a better understanding of species evolution in the tribe Polygonatae.  相似文献   

17.
The flavonoid glycosides of both varieties of Elmera racemosa were isolated and identified. The compounds were the monoglucosides of kaempferol, quercetin and myricetin, the rutinosides of the same aglycones, and the rhamnosylrutinosides of kaempferol and quercetin. All glycosides were linked at position-3 of the flavonols. The two varieties (var. racemosa and var. puberulenta C. L. Hitchcock) were identical. A comparison of the flavonoid chemistry of Elmera, Heuchera, and Tellima supports the existence of Elmera as a genus. A survey of several collections of Tellima grandiflora, Heuchera micrantha, and H. cylindrica showed only minor quantitative differences in the two-dimensional thin layer chromatograms from collection to collection. The possible origin of Tellima and Elmera from ancestral stock having Heuchera-like flavonoid chemistry is discussed.  相似文献   

18.
Maximum parsimony analysis of DNA sequence data from the internal and external transcribed spacer (ITS and ETS) regions of 18S-26S nuclear ribosomal DNA and the 3' trnK intron of chloroplast DNA from over 60 populations of Lasthenia sect. Amphiachaenia yielded a well-supported tree showing that the most common species of Lasthenia, L. californica sensu lato (s.l.), is not monophyletic. Members of Lasthenia californica s.l. belong to two well-supported but morphologically cryptic clades. One clade includes members of L. macrantha; the other represents a basally divergent lineage in L. sect. Amphiachaenia. Members of each clade can be diagnosed by pappus morphology and by geographic distribution, except for epappose plants that occur in a broad region of sympatry in central California. Overall diversification in the clade corresponding to L. sect. Amphiachaenia has been accompanied by minimal morphological divergence, which has resulted in previously underappreciated cryptic diversity.  相似文献   

19.
A cladistic analysis of Asarum was conducted to examine relationships among species within the genus and to test the monophyly of several groups of taxa that have often been treated as segregate genera. Thirty-two species were drawn from throughout the range of the genus, representing a broad sample of sections and all segregate genera. The data matrix included 37 characters derived from various aspects of vegetative and floral morphology. A strict consensus of all most parsimonious trees suggests that Asarum s.l. is monophyletic and consists of two main clades: an Asarum clade, which is characterized by connate styles and inferior ovaries, and an Asiasarum-Hexastylis-Heterotropa clade, which is characterized by ridges on the inner perianth surface, dorsal stigmas, and bifid style extensions. The latter is a large and morphologically diverse clade that includes the North American segregate Hexastylis and two Asiatic segregates. Examination of pollination mechanisms in the context of this phylogeny supports the conclusion that herkogamy, and thus obligate insect pollination, is derived from a plesiomorphic condition of autonomous self-pollination. Associated with herkogamy are characters such as glandular trichomes and other ornamentation of the surface of the calyx that probably represent increased specialization to attract insect pollinators. This study also indicates that chromosomal evolution has occurred via aneuploid decrease from an ancestral chromosome number of 2n = 26 to 2n = 24 in Heterotropa. The recognition of two subgenera, subgenus Asarum and subgenus Heterotropa, corresponding to the two clades in the cladistic analysis, is recommended.  相似文献   

20.
郭鹏  赵尔宓 《四川动物》2004,23(4):380-386
广义的竹叶青蛇属于Trimeresurus(sensu lato)包含有40多个物种,广泛分布在南亚和东南亚国家和地区。目前,该类群已经相继被划分为6个属:Trimeresurus(sensu stricto)、Tropidolaemus、Ovophis Protobothrops,Triceratolepidophis,Zhaoermia本文从形态、细胞以及分了系统学等方面对Trimeresurus(sensu lato)的分类和系统学研究进行综述。  相似文献   

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