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1.
Psychrooligotrophic fungi from Arctic soils of Franz Joseph Land   总被引:1,自引:1,他引:0  
Microfungi isolated from soil samples collected in Franz Joseph Land by means of the soil dilution and soil washing methods were screened for their ability to grow at low temperatures. The oligotrophic ability of the psychrotrophic strains was then determined on silica gel. A total of 40 taxa from 21 genera were isolated. Most isolates were species of Acremonium, Geomyces, Mortierella, Phialophora, Phoma, Thelebolus and sterile fungi. Eutypella scoparia, Hyphozyma variabilis and Ovadendron sulphureo-ochraceum are new records as soil and Arctic fungi. Most fungal isolates were psychrotrophic. The few psychrooligotrophs were species of Geomyces, Phoma, Thelebolus and Mortierella. Overall, our results suggest that the major component of an Arctic soil mycoflora should be active in one or more short growing seasons interspersed with periods of prolonged dormancy. Only a minor component, such as the small group of psychrooligotrophic fungi found in this study, may be expected to show continuous slow growth. Accepted: 22 November 1998  相似文献   

2.
Ju YM  Rogers JD  Hsieh HM 《Mycologia》2003,95(1):109-116
The diagnosis of Theissenia is emended to include taxa that lack a definite central perithecial columella and taxa that feature ascospores with a germ slit. Theissenia cinerea is described as a new species that lacks a perithecial columella; T. eurima is described as a new species with ascospores having a germ slit. The type species, T. pyrenocrata, is redescribed and compared with the new species. The taxonomic position of Theissenia is discussed.  相似文献   

3.
Sato H  Hattori T  Lee SS  Murakami N 《Mycologia》2011,103(3):598-609
We describe and illustrate two Strobilomyces species, S. seminudus and S. hongoi sp. nov. These two species have been confused and treated as a single species (i.e. S. seminudus). However recent studies based on population genetics have implied that they are reproductively isolated. In the present study we found that they are phylogenetically and morphologically distinct. The molecular phylogenetic trees inferred from the partial sequences of the largest subunit of RNA polymerase II (RPB1) and the second-largest subunit of RNA polymerase II (RPB2) support the differentiation of these two species as well as their differentiation from other related species. Strobilomyces seminudus is characterized by a stipe with an annular zone, becoming distinctly thickened near the apex and mottled with appressed-tomentose scales near the base. In contrast S. hongoi is characterized by a stipe with a remarkable reticulum at the upper and middle part and with minutely warty scales downward. Stipe characteristics also are useful for distinguishing these two species from other related species. In addition the incompletely reticulated basidiospores of these two species are also distinct from those of related species (i.e. S. foveatus).  相似文献   

4.
Mussaenda lancipetala X. F. Deng & D. X. Zhang, a new species of Rubiaceae from Yunnan Province, Southwestern China, is described and illustrated. The new species is characterized by its reverse herkogamous sexual system, its ovate-lanceolate corolla lobes with caudate apex, and corolla tube covered with sparse farinose pubescence, by which it is clearly distinguished from other species of Mussaenda.  相似文献   

5.
报道了在云南发现的玉叶金花属Mussaenda一新种——狭瓣玉叶金花M. lancipetala X. F. Deng & D. X. Zhang。狭瓣玉叶金花的性系统为柱头缩入式雌雄异位; 花冠裂片卵状披针形且具有细长的长尖头, 花冠管外被有粉末状的毛被, 可以很容易与玉叶金花属其他种类相区别。  相似文献   

6.
7.
The aim of this study was to investigate the survival of freeze-dried bacterial species stored at the International Patent Organism Depository (IPOD) and to elucidate the characteristics affecting survival. Bacterial strains were freeze-dried, sealed in ampoules under a vacuum (<1 Pa), and stored in the dark at 5 degrees C. The survival of a variety of species following storage for up to 20 years was analyzed. The survival of freeze-dried species was analyzed in terms of two stages, freeze-drying and storing. Nonmotile genera showed relatively high survival after freeze-drying. Motile genera with peritrichous flagella showed low survival rates after freeze-drying. Vibrio and Aeromonas, which produce numerous flagella, showed very low survival rates. In Lactobacillus, non-trehalose-fermenting species showed better survival rates after freeze-drying than did fermenting species, and those species with teichoic acid in the cell wall showed lower survival rates during storage than species with teichoic acid in the cell membrane. Human pathogenic species of Corynebacterium, Bacillus, Streptococcus, and Klebsiella showed lower survival rates during storage than nonpathogenic species within the same genus. Among Pseudomonas species, P. chlororaphis, the only species tested that forms levan from sucrose, showed the lowest survival rate during storage in the genus. Survival rates of Gram-negative species during storage tended to be lower than those of Gram-positive species, though Chryseobacterium meningosepticum had stable survival during storage. The conclusion is that smooth cell surfaces (i.e., no flagella) and lack of trehalose outside the cytoplasm improved survival rates after freeze-drying. Because desiccation is important for survival during storage, the presence of extracellular polysaccharides or teichoic acids is disadvantageous for long-term survival. The lower survival rates of freeze-dried Gram-negative bacteria compared with those of Gram-positive bacteria may be attributed to the thinner peptidoglycan layer and the presence of lipopolysaccharides on the cell wall in the former species.  相似文献   

8.
《Ibis》1930,72(S1):77-111
The only European and most familiar species * of the whole genus Cisticola , of which, according to ancient designation †, it is the representative type-species. It is also the species with the widest range.  相似文献   

9.
Monogeneans from three species of Cephalopholis, namely C. argus, C. sonnerati and C. boenak, are described from fish caught off New Caledonia, South Pacific, with comparisons with material from off Queensland, Australia. Pseudorhabdosynochus argus n. sp. from C. argus is present off New Caledonia and Australia; it is characterised by its male quadriloculate organ with very elongate cone, and its sclerotised vagina with anterior trumpet, coiled primary canal and distal part with two chambers and an accessory part. C. boenak has no monogeneans off New Caledonia, but off Australia it harbours Pseudorhabdosynochus sp., a new species which is morphologically related to P. argus. P. minutus n. sp. from C. sonnerati is characterised by its minute body and a sclerotised vagina with two spherical chambers. Diplectanum nanus n. sp. from C. sonnerati is characterised by its very small funnel-shaped male copulatory organ and minute body. A new species, Haliotrema sp. from C. sonnerati is characterised by a very elongate tubular penis; it is distinct from H. cromileptis Young, 1968 (redescribed herein from specimens collected from Cromileptes altivelis off New Caledonia). The species described here include the first members of Pseudorhabdosynochus and the first diplectanids described from species of Cephalopholis. There is no evidence for a clade of Pseudorhabdosynochus species specific to members of Cephalopholis, since the species described here share similarities with other species from Epinephelus. However, it is suggested that the gill structure of Cephalopholis spp. imposes selection toward small body sizes for monogeneans.  相似文献   

10.
S V Mezhzherin 《Genetika》1988,24(12):2197-2201
Genetic divergence between house mouse and gleaner mouse from different regions of Ukraine was estimated by electrophoresis at 26 loci. Four diagnostic loci were established among these species: IDH-1, Est-1,2,4. Genetic distance between species is 0.217, which is in accordance with genetic differences between other species of the genus Mus. The results obtained give evidence that house and gleaner mouse are different species.  相似文献   

11.
Nine species of small, filamentous green algae were identified from St. Lucia, in the Lesser Antilles. Observations were made on field-collected material and isolates obtained in unialgal culture. Acrochaete marchantiae (Setchell & Gardner) comb. nov. has been transferred from Pringsheimiella marchantae Setchell & Gardner. Trichothyra irregularis is described as a new genus and species, Blastophysa arrhiza Wille and B. polymorpha Kjellman are considered synonyms of B. rhizopus Reinke, and Phaeophila polymorpha Jao is considered synonym of P. dendroides (Crouan) Batters. These species were associated with a wide variety of substrate, including other algae, corals, rocks, and wood, with little apparent host specificity. All of the species recorded are new records for St. Lucia and five species are new records for the Caribbean.  相似文献   

12.
A new species to science, Hypolytrum subcompositus is described from Kodmin in South West Cameroon. The species is distinct from other African species and appears to have no close relatives. It is a fairly large perennial with a short erect rhizome with many crowded leaves at its end, and (below the leaves) 1–3 lateral culms carrying reduced leaves and a terminal cinnamon-whitish rather congested inflorescence.  相似文献   

13.
14.
Aim To better understand how environmental factors affect fish species richness across the state of Oregon. Location Oregon, U.S.A. Methods A database showing collection locations of 4911 fish specimens in the Oregon State University museum was modified by the Oregon Natural Heritage Program to include probable occurrences, and mapped within a grid of 375 hexagons that cover the state. The individual species maps of freshwater fish in Oregon were reviewed and revised by thirty regional fish biologists and then synthesized into a single map of native species richness. We used regression tree analysis (RTA) and multiple linear regression (MLR) to assess patterns of fish species richness with twenty environmental, three anthropogenic, and two historical variables. Results RTA explained 66% of the variation in native species richness, associating richness with annual air temperature range, minimum January temperature, introduced species richness, and stream density. MLR explained 68% of native species richness variation and associated richness with maximum July temperature, air temperature range, standard deviation of monthly temperature, stream density, introduced species richness, and basin connectivity. Main conclusions We conclude that for these data and at this scale, native fish species richness in Oregon is associated with annual climatic extremes, spatial variability of climate, stream density, basin connectivity, and introduced fishes.  相似文献   

15.
Mitotic chromosome counts are reported for 12 species of Oedogonium with the following distribution: two species with 13 chromosomes, two species with 16 chromosomes, five species with 17 chromosomes one species with 19 chromosomes, one species with 32 chromosomes, and one species with 38 + 1 chromosomes. Diploid strains of two species are illustrated and discussed. Cytological comparison of species establishes that there is great diversity in Oedogonium with relation to chromosome number, size, and morphology.  相似文献   

16.
A common first step during ecological restoration is reestablishing the local species pool through active reintroduction of individual plant species. Unfortunately, the regional species pool is often far too large to be of practical use during restoration. Methods are needed to produce manageable lists of key species for directed reintroduction. We used life history traits to target species from the regional species pool ( n = 900) for reintroduction to degraded Midwestern oak savanna remnants ( n = 8) in central Iowa, U.S.A. Beginning with the full regional species pool, we first used a priori filters to remove exotic species, species that live in permanently wet habitats, and species already present at the degraded remnant savannas. Next, we created a set of filters to target species with high priority for reintroduction, based on comparisons between the degraded and regional species pools. By this process, we identified perennial forbs and grasses that may be dispersal limited (ant, passive, or heavy wind-dispersed seeds) and are conservative in habitat requirement or have affinities for high-light environments. By applying these filters, we were able to winnow down the regional species pool to a manageable number of species ( n = 111) that we recommend for initial reintroduction efforts to the degraded savanna remnants. Furthermore, we specifically targeted members of the regional species pool that could fill under-represented ecological niches at the degraded savanna remnants and discuss potential benefits of adding these species for restoring ecosystem function.  相似文献   

17.
Corydalis hamata Franch. is described and illustrated. Variation within the species and relationships with related species are discussed. Corydalis pseudohamata Fedde is reinstated as a species.  相似文献   

18.
Two new genera, Gedoelstascaris and Orleppascaris, are proposed for species of ascaridoid nematodes occurring in crocodilians and previously included in Dujardinascaris. Species included in Gedoelstascaris are vandenbrandeni Baylis, 1929 as type species and australiensis Baylis, 1931 (= salomonis Kreis, 1940). These species occur in Crocodylus spp. in Africa and Australia respectively and are characterised by lips with a rostral plate, without interlocking processes or dentigerous ridges, with well-developed interlabia, lobulated ventriculus, and excetory pore in front of the nerve ring. Species included in Ortleppascaris are: nigra Gedoelst, 1916 (= tasmani Ortlepp, 1932) as type species; alata Baylis, 1947: antipini Mozgovoy, 1950. These species occur in Crocodylus, Caiman and Alligator and are characterized by flat lips with alate margins, without anterior rostral plate, interlocking processes or dentigerous ridges, with weakly developed interlabia, by an irregular-shaped ventriculus, excretory pore behind or between the subventral lips, and by the presence of lateral alae or cuticular thickenings in the oesophageal region. The significance of this proposal is discussed in relation to the radiation and dispersal of ascaridoids of crocodilians.  相似文献   

19.
Phylogenetic relationships were determined for 76 partial P-element sequences from 14 species of the melanogaster species group within the Drosophila subgenus Sophophora. These results are examined in the context of the phylogeny of the species from which the sequences were isolated. Sequences from the P-element family fall into distinct subfamilies, or clades, which are often characteristic for particular species subgroups. When examined locally among closely related species, the evolution of P elements is characterized by vertical transmission, whereby the P-element phylogeny traces the species phylogeny. On a broader scale, however, the P-element phylogeny is not congruent with the species phylogeny. One feature of P-element evolution in the melanogaster group is the presence of more than one P-element subfamily, differing by as much as 36%, in the genomes of some species. Thus, P elements from several individual species are not monophyletic, and a likely explanation for the incongruence between P-element and species phylogenies is provided by the comparison of paralogous sequences. In certain instances, horizontal transfer seems to be a valid alternative explanation for lack of congruence between species and P-element phylogenies. The canonical P-element subfamily, which represents the active, autonomous transposable element, is restricted to D. melanogaster. Thus, its origin clearly lies outside of the melanogaster species group, consistent with the earlier conclusion of recent horizontal transfer.   相似文献   

20.
A new species, Cyperus rheophyticus , is described from seasonally submerged habitats in forest streams and rivers in South West Cameroon (500–1350 m). Cyperus rheophyticus is most similar to C. brevifolius ssp. brevifolius (syn. Kyllinga brevifolius ), a less slender species with a stronger rhizome, larger spikeiets and glumes with a spinose keel; also the anther and achene are larger in that species.  相似文献   

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