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1.
Since 2007, reoccurring large-scale green algae blooms have caused deleterious effects to the estuarine ecosystem of Yellow Sea, northern China and subsequent economical losses. Previous surveys indicated the green tides were initiated in the coastal water of southern Jiangsu province where Porphyra farming was intensively conducted; however, the main ‘seed source’ of floating green algae is still under debate. Ulva prolifera was confirmed to be the major causative species of green tides. The multiple sympatric ulvoid species in the natural environment has complicated species identification in both field surveys and laboratory studies due to their morphological plasticity. Thus, we developed a genetic identification key based on restriction fragment length polymorphism (RFLP) analysis of the ITS nuclear marker to discriminate the common Ulva and Blidingia species in the Yellow Sea. Ten genetic lineages (1 in Blidingia, 9 in Ulva) were detected along the coast of China through phylogenetic analysis of ITS sequences. They can be separated by virtual restriction digestion using the four selected restriction enzymes (BspT107 I, EcoO109 I, Hin1 I and VpaK11B I). With additional PCR amplification of the 5S spacer region, we were able to discriminate U. prolifera from Ulva linza. Using this genetic key, we screened macroalgal samples collected from the coast of the Yellow Sea, and the results indicated 6 common lineages (U. prolifera, U. linza, Ulva compressa, Ulva pertusa, Clade 6 and Blidingia sp.) in this region, which could be explicitly distinguished by a single enzyme (BspT107 I) coupled with 5S spacer polymorphism. U. prolifera was confirmed to be present on the Porphyra aquaculture rafts with seasonal variation in the species composition. This genetic key will facilitate our long-term field surveys to investigate the origin of the floating U. prolifera and furthermore to explore its bloom dynamics along the coast of the Yellow Sea. It also provided a framework for the future inclusion of more Ulva species, which will expand the usage of this key.  相似文献   

2.
Paul A. Fryxell 《Brittonia》1976,28(3):318-325
Two new species ofBriquetia,B. sonorae andB. inermis, are described from northern Mexico, and another species that ranges from Mexico to Bolivia is transferred into the genus asB. spicata. The genus (previously known as monotypic, Paraguayan-Brazilian) is thereby enlarged from one species to four, and its geographical and morphological limits are greatly expanded. Also, a Mexican species ofAbutilon is transferred toHochreutinera, asH. amplexifolia, enlarging that genus from one to two species. On the basis of this new information, the limits of the informalBriquetia alliance are reconsidered; it is considered to include onlyBriquetia, Dirhamphis, andBatesimalva.  相似文献   

3.
New species ofBletia from Mexico are described and illustrated:B. concolor, B. similis, andB. urbana. The identity ofB. campanulata Llave & Lex. is discussed, andB. reflexa Lindl. is considered to be a distinct species. Several South American epithets are treated as synonyms ofB. campanulata. A key to the recognized species ofBletia is given.  相似文献   

4.
A comparison of some genera of the Condaminecae (Rubiaceae) with a few taxa of closely related tribes (Rondeletieae, Calycophylleae, and Cinchoneae) revealed that some species ofChimarrhis (Condamineeae s. 1.),Bathysa (Rondeletieae), andCalycophyllum (Calycophylleae) are often misassigned to genera. The taxonomic significance of calycophylls is discussed; the generic boundaries ofChimarrhis, Bathysa, andCalycophyllum are reevaluated; and their similarities and differences are discussed. As a result, a new calycophyllous species ofChimarrhis from the Amazon,C. gentryana, is described, two of its species are transferred toBathysa (B. Bathysoides, B. perijaënsis), and one species ofBathysa (B. difformis) is reduced to synonymy underChimarrhis (C. turbinata).  相似文献   

5.
E. Lipkow 《BioControl》1965,10(4):377-381
Summary The endoparasitic branconidsCentistes lucidator Nees andBlacus ruficornis Nees were reared fromTachyporus-species, common staphylinids of cultivated fields in Central Europe.Centistes occured inTachyporus hypnorum, obtusus, solutus andchrysomelinus, while only oneBlacus was found inT. obtusus. In the relatively cool and humid summer 1963 in the surroundings of Kiel (Germany) the rate of parasitism ofTachyporus-species byCentistes was about 3 to 8% (table 1). — During oviposition ofCentistes the host does not show any reaction. The immature stages develop in the haemocoele of the beetle. The final-instar larva emerges from the host beetle and spins a cocoon beside of it. The beetle dies while the parasite larva is emerging from it. The first-instar larva is described and illustrated. Both species hibernate as first-instar larvae in the beetles, which have an obligatory diapause and become adults in the next summer.   相似文献   

6.
Abstract:Biatora britannica sp. nov. is described from Wales. The species is the sorediate sister taxon of the Madeiran Biatora hertelii. The close relationship is supported by the presence of the hymenial pigment Hertelii-green, which is hitherto known only from these two species. Molecular data from the nuclear ITS-region of 14 Biatora -species renders further support for the close relationship of both species. Sterile, sorediate material from the British Isles earlier referred to B. efflorescens may in fact belong to B. britannica.  相似文献   

7.
Plant species richness and productivity often show a positive relationship, but the underlying mechanisms are not fully understood, especially at the plant species level. We examined how growing plants in species mixture influences intraspecific rates of short-term carbon (C-) translocation, and determined whether such short-term responses are reflected in biomass yields. We grew monocultures and mixtures of six common C3 grassland plant species in outdoor mesocosms, applied a 13C-CO2 pulse in situ to trace assimilated C through plants, into the soil, and back to the atmosphere, and quantified species-specific biomass. Pulse derived 13C enrichment was highest in the legumes Lotus corniculatus and Trifolium repens, and relocation (i.e. transport from the leaves to other plant parts) of the recently assimilated 13C was most rapid in T. repens grown in 6-species mixtures. The grass Anthoxanthum odoratum also showed high levels of 13C enrichment in 6-species mixtures, while 13C enrichment was low in Lolium perenne, Plantago lanceolata and Achillea millefolium. Rates of C loss through respiration were highest in monocultures of T. repens and relatively low in species mixtures, while the proportion of 13C in the respired CO2 was similar in monocultures and mixtures. The grass A. odoratum and legume T. repens were most promoted in 6-species mixtures, and together with L. corniculatus, caused the net biomass increase in 6-species mixtures. These plant species also had highest rates of 13C-label translocation, and for A. odoratum and T. repens this effect was greatest in plant individuals grown in species mixtures. Our study reveals that short-term plant C translocation can be accelerated in plant individuals of legume and C3 grass species when grown in mixtures, and that this is strongly positively related to overyielding. These results demonstrate a mechanistic coupling between changes in intraspecific plant carbon physiology and increased community level productivity in grassland systems.  相似文献   

8.
Within the food web of estuarine and marine rocky shore ecosystems phytophagous mites of terrestrial and marine origin constitute an important part as grazers on algae and as a food source for certain arthropods, especially zoophagous mites. This investigation deals with the feeding biology ofHyadesia fusca taking as an example a population located on an artificial rocky shore of the middle Weser estuary in Northern Germany. The species is characterized by a broad diet range; in feeding experiments diatoms, lichens, detritus as well as blue, red and green algae were accepted. Even analyses of faecal pellets produced by field specimen suggest a non-specific feeding habit. However, the influence of certain diets on mortality, offspring number and rearing success showed that the food quality differs significantly. The most suitable food, the UlvaceaeBlidingia, was clearly preferred in a series of pairwise choice tests. These findings correlate with the vertical zonation of the field population i.e.: higher population densities in the vegetation zone dominated byBlidingia. It can be concluded that in addition to abiotic factors food supply could play an important role for distribution patterns of phytophagous mites.  相似文献   

9.
Morphological, isozyme, and cytological analyses of the small, pale-scaled polystichums from oakdominated montane rain forests in Costa Rica and Mexico reveal the presence of a separable undescribed species endemic to the Cordillera de Talamanca of Costa Rica. The new taxon,Polystichum lilianae, is an allotetraploid hypothesized to have the sympatricP. turrialbae as one diploid progenitor based on isozyme characters. The isozyme and morphometric data also support the inclusion ofP. smithii, described from southern Mexico, inP. turrialbae, described from Costa Rica. The namePolystichum fournieri, formerly used for all of these plants, applies to species endemic to Oaxaca and Chiapas, Mexico. It is not a progenitor ofP. lilianae.  相似文献   

10.
The Case for Borojoa patinoi in the Chocó Region, Colombia. Economic Botany 51(1): 39-48. 1997. The economic botany of the tree speciesBorojoa patinoi is presented after consulting all available literature and visiting the region.Borojoa patinoi is a noteworthy species in that it is endemic to the biogeographic Chocó region, its fruits have high market value, and it is an understory tree, which means it can be cultivated without clearing the overstory trees. This paper reviews the literature on the taxonomy and phytogeography of the genus, as well as the production ecology of the species. Two net present value models are presented to analyze the species economically. From the models, we conclude that in many areas in the Chocó, plantingB. patinoi trees is likely to be economically more competitive than planting commercial timber species. Furthermore, monocultures ofB. patinoi may not be the economically optimal production system. BesidesB. patinoi, some other Chocó species with edible fruits are suggested for further research.  相似文献   

11.
Periodontitis is an infectious inflammatory disease that results in the destruction of the tooth-supporting (periodontal) tissues. The Gram-negative anaerobic species Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, (also known as the “red complex” species) are highly associated with subgingival biofilms at periodontitis-affected sites. A major chemokine produced by the gingival epithelium in response to biofilm challenge, is interleukin (IL)-8. The aim of this in vitro study was to investigate the relative effect of the “red complex” species as constituents of subgingival biofilms, on the regulation of IL-8 by gingival epithelia. Multi-layered organotypic human gingival epithelial cultures were challenged with a 10-species in vitro subgingival biofilm model, or its 7-species variant, excluding the “red complex”. IL-8 gene expression and secretion analyses were performed by qPCR and ELISA, respectively. After 3 h, both biofilms up-regulated IL-8 gene expression, but the presence of the “red complex” resulted in 3-fold greater response. IL-8 secretion was also up-regulated by both biofilms, with no differences between them. After 24 h, the 10-species biofilm reduced IL-8 secretion to 50% of the control, but this was not affected when the “red complex” was absent. In conclusion, as part of biofilms, “red complex” species differentially regulate IL-8 in gingival epithelia, potentially affecting the chemotactic responses of the tissue.  相似文献   

12.
13.
Thewaxy proteins encoded by the genomes A, B, and D in polyploid wheats and related diploid species were isolated by SDS-PAGE. The N-terminal amino acid sequences of mature proteins and V8 protease-induced fragments were determined. A total of five amino acid substitutions was detected in these sequences, which represent about 10% of the whole sequences of thewaxy proteins. A comparison of these sequences in polyploid wheats with those in related diploid species revealed the following: (i)waxy proteins encoded by the A genome of polyploid wheats were identical to that ofTriticum monococcum, (ii) thewaxy protein encoded by the B genome ofT. turgidum was identical to that ofT. searsii, but differed from those ofT. speltoides andT. longissimum by one amino acid substitution, (iii) thewaxy protein encoded by the B genome ofT. aestivum differed from that encoded by the B genome ofT. turgidum by one amino acid substitution, and (iv) thewaxy protein encoded by the D genome ofT. aestivum was identical to that ofT. tauschii.  相似文献   

14.
15.
Stable n-species ecosystem models may be expanded into larger (n + 1)-species stable models when an invading species is introduced. Such invasions are referred to as being successful due to the elasticity of the original community. Elasticity is dependent upon the interaction terms of both the original community members and the invading species. Feasibility constraints for elasticity and inelasticity are presented here for these terms in the context of a generalized ecosystem model where invasion causes only minor displacements in equilibrium population densities.  相似文献   

16.
The green algal genus Blidingia (Ulvales), reported for the first time in California only 4 years ago, is now found to be fairly widely distributed there as B. minima (Nägeli ex Kützing) Kylin var. minima. B. minima var. subsalsa (Kjellman) Seagal is now recorded for California. Ulva vexata Setchell and Gardner [Enteromorpha vexata (Setch. & Gardn.) Doty] is reduced to varietal status as B. minima var. vexata, and is reported, to be found in 2 ecological forms. Forms with expanded, ulvoid blades are common to exposed localities and is the form described by Setchell & Gardner. Smaller, narrower, enteromorphoid forms are found near river mouths and are the kind referred to by Doty. There are many intermediate forms of this variety. Characters which are used to separate Blidingia from Enteromorpha are critically evaluated.  相似文献   

17.
The article comprises three subsequently published studies of the taxonomy of Cuban cyanophyte/cyanobacterial flora: (4)Lyngbyopsis willei: This oscillatorialean genus and species, described byGardner (1927) from mountain creeks in Puerto Rico, was found more than 50 years later in similar localities in Cuba. The morphological variability of the Cuban populations is described and similarity with the genusSchizothrix (sect.Inactis) discussed. —(5)Cylindrospermum-species: The morphological variability of twenty-oneCylindrospermum-populations collected in Cuba was studied, documented by graphical methods and compared with the published data. Four new taxa were recognized (C. minutissimum v.rinoi, C. zonatum, C. bourrellyi, andC. desikacharyi). The other populations belong to the variation ranges ofC. breve, C. minutissimum, C. michailovskoense, andC. muscicola v.kashmiriense.— (6)Gomphosphaerioideae-species: Fifty eight populations (9 species) of the subfamilyGomphosphaerioideae (Microcystaceae, Chroococcales) from freshwater biotopes of Cuba were evaluated: Four planktic species with a probable cosmopolitan distribution were found (Coelosphaerium kuetzinginianum, C. minutissimum, Snowella lacustris andCoelomoron pusillus), and from the genusCoelomoron Buell two new species,C. microcystoides andC. vestitus were described. The tropical planktic speciesWoronichinia fremyi forms occasionally water blooms in larger reservoirs. Two tropical species from the genusGomphosphaeria Kütz, were recognized,G. multiplex (Nyg.) c. n. andG. semen-vitis sp. n.  相似文献   

18.
The cytochromeb genes of all living species ofBubalus, including the river type and the swamp type of domestic buffaloes (Bubalus bubalis), were sequenced to clarify their phylogenetic relationships. These sequences were compared together with the African buffalo (Syncerus caffer) and banteng (Bos javanicus) sequences as an outgroup. Phylogenetic trees ofBubalus species based on the DNA sequences of the cytochromeb gene demonstrated that the tamaraw (Bubalus mindorensis), endemic to the Philippines, could be classified into the subgenusBubalus, not the subgenusAnoa. The divergence time between the lowland anoa (B. depressicornis) and the mountain anoa (B. quarlesi) was estimated at approximately 2.0 million years (Myr), which is almost the same as the coalescence time for theBubalus sequences. This large genetic distance supports the idea that the lowland anoa and the mountain anoa are different species. An unexpectedly large genetic distance between the river and the swamp type of domestic buffaloes suggests a divergence time of about 1.7 Myr, while the swamp type was noticed to have the closest relationship with the tamaraw (1.5 Myr). This result implies that the two types of domestic buffaloes have differentiated at the full species level.  相似文献   

19.
Biodiversity experiments have shown that high species richness increases productivity in forests. However, forests are diverse regarding community composition. It is unclear how species identity and species composition could contribute to the variation of productivity and how their effects interact with species richness. Here we used data from a 9-year-old planted forest experiment with 40 species to test the effects of species identity and species composition on productivity. The plots in the experiment were designed with various compositions across richness levels. We found that for the top 25 species compositions with the highest volume increment there were six monocultures (24%), eight 2-species mixtures (32%) and eleven 4-species mixtures (44%). Schima superba monoculture had the highest volume in the last study year and highest volume increment over five years, while 2-species and 4-species mixtures with Nyssa sinensis or Liquidambar formosana resulted in high average above-ground volume accumulation. Most of the high-productivity species were deciduous with arbuscular mycorrhizal (AM) associations. In addition, the percentage of AM species in plots had a positive significant effect on both above-ground volume in 2018 and increment from 2013 to 2018. While the percentage of evergreen species showed no significant effect on above-ground volume increment, it did significantly decrease the above-ground volume in 2018. Overall, our results encourage reforestation management to consider species identity and species compositions of deciduous and/or AM species, such as Schima superba, Nyssa sinensis or Liquidambar formosana in the studied subtropical area, if the purpose is to enhance ecosystem productivity.  相似文献   

20.
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