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1.
喜光榕树和耐荫榕树光适应机制的差异   总被引:11,自引:0,他引:11  
100%和36%光强下生长的喜光的斜叶榕的光合能力高于耐荫的假斜叶榕,而热耗散能力与之相似,说明强光下斜叶榕主要通过光合作用利用光能和热耗散、假斜叶榕主要通过热耗散防御光破坏.100%光强下生长的两种榕树的日间光抑制程度相似,但叶表光强相同情况下各光强下生长的假斜叶榕的光抑制均比斜叶榕严重.100%光强下假斜叶榕叶片悬挂角大于斜叶榕,导致日间叶表光强低于斜叶榕,这可能是两种榕树日间光抑制程度相似的原因,表明叶片悬挂角的适应变化对假斜叶榕有重要的意义.  相似文献   

2.
Specimens belonging to Tortula subulata complex ( T. inermis , T. mucronifolia and T. subulata ) were analysed using a combination of morphometric methods based on quantitative characters [principal component analysis (PCA), discriminant analysis (DA); 76 samples)] and molecular methods (ITS1 – 5.8S rRNA gene and ITS2; 47 samples) to assess patterns of morphological and molecular differentiation within this complex of taxa. The study shows that four species can be recognized: T. mucronifolia , T. subulata , T. inermis and T. subulata var. angustata with bistratose border, which is elevated to the species rank as T. schimperi nom. nov. The most valuable quantitative characters for identification of these species are the strata number of the marginal laminal cells, the ratio of middle marginal laminal cell width/middle marginal laminal cell length, basal membrane of peristome length, middle laminal cell width and papillae number on the middle laminal cells. The internal transcribed spacer (ITS) data suggest that this group of taxa is not monophyletic, T. mucronifolia being close to Protobryum bryoides (= Tortula protobryoides ). The remaining species seem to be a monophyletic group, T. schimperi being the sister group of the clade composed by T. inermis and T. subulata . T. subulata is considered to be of high morphological variability, for which ITS sequences did not resolve the internal relationships.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 333–350.  相似文献   

3.
报道了安徽省玄参科一新记录属-水茫草属(Limosella L.),及一新记录种-水茫草(Limosella aquatica L.).  相似文献   

4.
观测了不同光强下生长的两种榕树幼苗叶片的光合能力、比叶重(LMA)、氮含量及在光合机构中的分配.结果表明,两种榕树幼苗的最大净光合速率(Pmax)均随生长光强的升高而升高,这与LMA、单位面积氮含量(NA)和光合氮利用效率随生长光强的升高而升高有关.除36%光强下外,相同光强下生长的喜光的斜叶榕(Ficus tinctoria)的Pmax均显著高于耐荫的假斜叶榕(Ficus subulata),这与其叶片中氮在羧化组份和生物力能学组份中的分配系数、LMA和NA较高有关.  相似文献   

5.
Journal of Plant Research - Limosella is a small aquatic genus of Scrophulariaceae of twelve species, of which one is distributed in northern circumpolar regions, two in southern circumpolar...  相似文献   

6.
1. As species are often considered discrete natural units, interspecific sexual interactions are often disregarded as potential factors determining community composition. Nevertheless reproductive interference, ranging from signal jamming to hybridization, can have significant costs for species sharing similar signal channels. 2. We combined laboratory and field experiments to test whether the coexistence of two congeneric ground-hopper species with overlapping ranges might be influenced by sexual interactions. 3. In the laboratory experiment the number of conspecific copulations of Tetrix ceperoi decreased substantially in the presence of Tetrix subulata. Males of T. ceperoi performed more mating attempts with heterospecific females, whereas females of T. subulata rejected these heterospecific approaches more often than those of conspecifics. Although no heterospecific matings occurred in the laboratory, the reproductive success of T. ceperoi was reduced substantially in field experiments. Negative effects on T. subulata were found only at high densities. 4. Our results suggest that reproductive interference could have similar consequences as competition, such as demographic displacement of one species ('sexual exclusion'). As reproductive interference should be selected against, it may also drive the evolution of signals (reproductive character displacement) or promote habitat, spatial or temporal segregation.  相似文献   

7.
对新疆维吾尔自治区的蚱类昆虫物种多样性进行了修订和澄清.该地区共记录3种蚱:钻形蚱Tetrix subulata (Linnaeus,1758),隆背蚱Tetrix tartara (Saussure,1887)和土氏蚱Tetrix tuerki (Krauss,1876).同物异名修订如下:1)钻形蚱Tetrix subulata (Linnaeus,1758)=拟钻形蚱Tetrix subulatoides Zheng,Zhang,Yang&Wang,2006,syn.nov.;2)隆背蚱Tetrix tartara (Saussure,1887)=福海蚱Tetrix fuhaiensis Zheng,Zhang,Yang&Wang,2006,syn.nov.,=精河蚱Tetrixjingheensis Liang&Zheng,1998,syn.nov.,=亚锐隆背蚱Tetrix tartara subacuta Bey-Bienko,1951,syn.nov.,=新疆蚱Tetrix xinjiangensis Zheng,1996,syn.nov.;3)土氏蚱Tetrix tuerki (Krauss,1876)=瘤股蚱Tetrix torulosifemura Deng,2016,nomen nudum.本文更新了3种蚱的分布信息,排除了波氏蚱Tetrix bolivari Saulcy,1901在中国、以及暂时排除日本蚱Tetrixjaponica (Bolívar,1887)在新疆的分布.  相似文献   

8.
9.
Three new species of Thraulodes from Venezuela are described. One species is known from male and female imagines, and the other two only from male imagines. With this, the known Thraulodes species for Venezuela are four. A key for the male imagines of the known species of Thraulodes from Venezuela is provided.  相似文献   

10.
Labonne JD  Hilliker AJ  Shore JS 《Heredity》2007,98(6):411-418
To explore the rate of recombination resulting from male vs female meiosis, crosses were performed using distylous Turnera subulata as well as a cross involving the introgression of genes from T. krapovickasii into T. subulata. We assayed four loci on the chromosome bearing the S-locus as well as two loci on each of two other linkage groups. Substantial and consistent dimorphism in recombination rates was found with female meiosis resulting in as much as a approximately 6-fold increase relative to male. Aberrant single locus segregation ratios occurred for some loci, particularly when the male (pollen) parent was heterozygous and the cross involved introgressed genes. The extreme trend of greater recombination resulting from female meiosis was, however, maintained in crosses where no aberrant ratios occurred, indicating that the sex dimorphism in recombination is not the result of aberrant segregation. We also exploited this distylous species and tested whether there is recombination suppression around the S-locus because of an inversion or other chromosome rearrangement(s). We found no significant evidence for recombination suppression.  相似文献   

11.
Chemical communication in the sexually deceptive orchid genus Cryptostylis   总被引:2,自引:0,他引:2  
Pollination by sexual deception is among the most intriguing of orchid pollination syndromes. Odours are well established as the primary stimuli for sexually attracting the male insect pollinators in these orchids. We applied gas chromatography with electroantennographic detection (GC-EAD) to investigate chemical communication between the sympatric, but morphologically distinct, orchids Cryptostylis erecta and C. subulata and their pollinators. Cryptostylis is unusual among sexually deceptive orchid genera in that all five Australian species share the same pollinator, the ichneumonid wasp Lissopimpla excelsa , but hybrids are unknown. We show that volatile odour compounds are not produced in detectable amounts in either species. Floral extracts containing many low-volatility compounds showed considerable differences in composition between C. erecta and C. subulata . By contrast, GC-EAD revealed the male wasp pollinators are electrophysiologically responsive to the same GC peak on two different kinds of GC column in both orchids. This leads us to predict that a single compound is the sexual attractant in all Australian Cryptostylis . The apparent conservation of chemical signals among distinct species contrasts with that of other sexually deceptive orchids that are often morphologically similar but reproductively isolated by their different chemical signals.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 199–205.  相似文献   

12.
Speleocola Lipovsky 1952 is redescribed. New species S. clangula off Rhipidomys sp., Venezuela, and S. nolae off Peropteryx kappleri, Venezuela, are described. A key to the 5 included species is given.  相似文献   

13.
Tintinnids were identified in 256 samples from 60 stations inthe North Sea investigated by a German multidisciplinary [Zirkulationund Schadstoffumsatz in der Nordsee (ZISCH)] program, duringlate spring of 1986. Tbe distribution of the most frequentlyoccurring species. Parafavella elegans, P.denticulatn, Acanthostomellanorvegica, Helicostomella subulata, Prychocylis unurla, Stenosemellanivalis, Tintinnopsis beroidea and T.parvula, was described.Some species showed a similar horizontal distribution. However,a vertical division was evidenced after analyzing species abundancesagainst temperature, salinity, depth and  相似文献   

14.
Eight new species of Neoelmis from Venezuela are described, and a key is given to the species. N.pusio of Trinidad and Tobago is included in the key because it seems likely that it may occur in Venezuela.  相似文献   

15.
Abstract. Subgenus Otarrha is established in genus Chimarra to include eighteen described species formerly placed either in subgenus Chimarra or unplaced to subgenus, and thirteen new species. All species are Neotropical, with collective distributions primarily in the Antilles (Greater and Lesser) and northern South America. One species occurs in southeastern Brazil and another species in Costa Rica and Panama. New species are described, recognized species redescribed (except for C. diannae and C. koki ), and a key to the identification of males in the subgenus is provided. Additionally, characters supporting monophyly of the subgenus and a phylogeny of its species are proposed. Described species transferred to this subgenus include Chimarra cubanorum Botosaneanu, C . diakis Flint, C . diannae Flint & Sykora, C . dominicana Flint, C . garciai Botosaneanu, C . guapa Botosaneanu, C . jamaicensis Flint, C . koki Botosaneanu, C . machaerophora Flint, C . patosa Ross, C . puertoricensis Flint, C . quadrifurcata Botosaneanu, C . retrorsa Flint, C . rossi Bueno-Soria, C . sensillata Flint, C . septemlobata Flint, C . septifera Flint and C . spinulifera Flint. Chimarra patosa is designated the type species of the subgenus. New species described in Otarrha include Chimarra amazonia (Peru), C . barinas (Venezuela), C . darlingtoni (Cuba), C . diaphora (Venezuela), C . incipiens (Venezuela), C . odonta (Brazil), C . parene (Peru), C . parilis (Peru), C . particeps (Peru), C . peruana (Peru), C . phthanorossi (Colombia), C . redonda (Dominican Republic) and C . tachuela (Venezuela). Two additional species are described and left incertae sedis to subgenus, Chimarra usitatissima Flint and C . angularis , sp.n. (Venezuela, Guyana).  相似文献   

16.
The subgenus Chimarrita of the genus Chimarra is erected to include three described species, formerly placed in the subgenus Chimarra , and fifteen new species, all with distributions in the Greater Antilles or South America. A phylogeny for the species in the subgenus, and characters supporting monophyly of the subgenus Chimarrita , are proposed, as well as evidence for the monophyly of the subgenera Chimarra and Curgia . Keys are provided for the males and known females of the subgenus. Described species transferred to this subgenus are Chimarra simpliciforma Flint, Chimarra rosalesi Flint, and Chimarra maldonadoi Flint. Chimarra simpliciforma is designated the type species for the subgenus. New species in Chimarra ( Chimarrita ) described in this paper include: Chimarra akantha (Brazil), C . camella (Brazil), C . camura (Brazil), C . chela (Venezuela), C . forcipata (Venezuela), C . heligma (Brazil), C . heppneri (Peru), C . kontilos (Brazil), C . majuscula (Brazil), C . merengue (Dominican Republic), C . neblina (Venezuela), C . prolata (Ecuador), C . pusilla (Venezuela), C . tortuosa (Brazil), and C . xingu (Brazil).  相似文献   

17.
The new caffeic acid derivative, subulatin (1), was isolated from in vitro cultured liverworts, Jungermannia subulata, Lophocolea heterophylla, and Scapania parvitexta. The structure of 1 involved two caffeic acids, D-glucose, and 2-carboxy-6-(1,2-dihydroxy-ethyl)-4,5-dihydroxy-5,6-dihydro-4H-pyran. The connectivity of those and the absolute stereochemistry of 1 were elucidated on the basis of spectroscopic evidence. The antioxidative activity of 1 was comparable to that of alpha-tocopherol. (2'R)-Phaselic acid (2a) and (-)-9,2'-epiphylloyl-L-malic acid (4) were also isolated from J. subulata and L. heterophylla, respectively. A chiral HPLC analysis of the p-bromobenzoyl-malic acids derived from 2a showed that 2a from J. subulata was unusual (+)-trans-caffeoyl-D-malic acid.  相似文献   

18.
Venezuela possesses a great variety of coastal environments allowing for a high diversity of marine species. However, systematic studies on marine invertebrates are scarce, especially on polychaetes. The family Syllidae is poorly known, and only 14 genera and 42 species have been reported from this country. A total of 13 genera and 26 species the Syllidae were identified from benthic samples collected on different substrata of the northeastern coast of Venezuela. Of these, seven genera and 16 species constitute new records for Venezuela: Odontosyllis guillermoi, Syllides floridanus, Salvatoria clavata, Salvatoria limbata, Sphaerosyllis longicauda, Parapionosyllis longicirrata, Trypanosyllis parvidentata, Trypanosyllis vittigera, Opisthosyllis sp., Syllis amica, Syllis armillaris, Syllis gracilis, Syllis pseudoarmillaris, Syllis vittata, Parasphaerosyllis indica and Myrianida convoluta.  相似文献   

19.
Some Crustacea Copepoda from Venezuela   总被引:5,自引:5,他引:0  
The study of 38 samples of aquatic fauna from Venezuela increased the number of known species here from 28 to 66. Fifteen new species for science are described. A list of Copepoda known from the other regions of South America is presented. From this list, it can be said that only 50% of the inland water Copepoda living actually in Venezuela are known.  相似文献   

20.
The distribution of 14 iridoid glucosides in 14 Plantago L. species (44 samples corresponding to 18 taxa) was shown. P. tenuiflora and P. gentianoides were studied for iridoids for the first time. The iridoid patterns showed a good correlation with morphological and other chemical features of the representatives of genus Plantago. The studied species are grouped together according to the iridoid patterns: species containing mainly aucubin (P. major, P. cornuti, P. gentianoides); species containing aucubin and aucubin derivatives (P. subulata, P. media); species containing aucubin and catalpol (P. lanceolata, P. altissima, P. argentea, P. lagopus, P. atrata); species containing aucubin and plantarenaloside (P. afra, P. scabra).  相似文献   

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