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1.
The new species Semenovia pulvinata Pimenov & Kljuykov, S. dissectifolia Ukrainskaja & Kljuykov, S. imbricata Ukrainskaja & Kljuykov, and S. vachanica Ukrainskaja & Kljuykov from the mountains of Pamiro‐Alai, Tajikistan and adjacent Afghanistan, are described and illustrated. For the Chinese species S. millefolia (Diels) V. M.Vinogr. & Kamelin, also known as Heracleum millefolium Diels, the correct name is S. torilifolia (H. Boissieu) Pimenov comb. nov. based on Peucedanum torilifolium H. Boissieu. For another closely related Chinese species, Peucedanum malcolmii Hemsl. & H. Pearson, also belonging to Semenovia, the new combination S. malcolmii (Hemsl. & H. Pearson) Pimenov is proposed. Heracleum thomsonii C. B. Clarke var. glabrior C. B. Clarke from Kashmir (Ladakh) is regarded as an independent species of Semenovia, S. glabrior (C. B. Clarke) Pimenov & Kljuykov.  相似文献   

2.
Noel H. Holmgren 《Brittonia》1998,50(2):159-164
Two Nevada species are described here for the first time: Penstemon tiehmii N. H. Holmgren, which is endemic to Mount Lewis of the Shoshone Range in Lander County; and Penstemon rhizomatosus N. H. Holmgren, which is endemic to the central Schell Creek Range in White Pine County. They both belong to section Saccanthera and are closely related to P. kingii S. Watson, a Great Basin endemic of valley sagebrush habitats. Both new species are talus plants of higher elevations and differ from P. kingii principally in their rhizomatous habit, petiolate leaves, and pubescence of shorter hairs.  相似文献   

3.
《Journal of bryology》2013,35(4):435-441
Abstract

S. subsecundum Nees and S. auriculatum Schimp. are distinct species which can always be separated when well grown. Poorly grown S. auriculatum can resemble S. subsecundum, but can almost invariably be distinguished by careful selection of the larger stem leaves in any gathering. When the size of both stem and branch leaves is taken into account, confusion can hardly ever arise, even with depauperate forms. S. inundatum Russ. is not specifically distinct from S. auriculatum, and is recombined as S. auricula tum Schimp. var. inundatum (Russ.) M. O. Hill.  相似文献   

4.
Abstract

Festuca alpestris R. et S. in the Alps near Belluno.—Some populations of Festuca from the F. varia aggr. occurring in the south-eastern Alps near Belluno have been recognized as belonging to F. alpestris R. et S. The relationships between this species and F. calva (Hackel) Richter from the Julian Alps are discussed and the diacritic characters are newly defined.  相似文献   

5.
Abstract

«Poterium spinosum» L. in Western Mediterranean at Calamosca (Capo S. Elia, Sardegna). — The Author has studied the station of Poterium spinosum at Calamosca, a small valley of S. Elia Cape, near Cagliari, Sardinia. Im Sardinia this place is the only one where P. spinosum grows on the contrary to the information given in RIKLI (1946) where P. spinosum is indicated as growing everywhere along the coast in the island. As it is known, P. spinosum is very common along the coast in Greece, Lebanon, Israel, Syria; is absent in Egypt; is present in the calcareous part of Cyrenaica, in Sicily between Siracusa and Capo Passero; it reaches westwards the small island of Djerba (Tunisia) and Calamosca (S. Elia Cape — Sardinia). In Dalmatia has been reported for Spalato (Split) and Ragusa (Dubrovnik). It has not been found lately at Fiume (Rijeka) neither at Tivoli (Latium), Cotrone (Basilicata) and Bari (Apulia). P. spinosum at Calamosca in the higher part of the station is tipically rock-dwelling, lower is still rock-dwelling but associated with Thymus capitatus H. et Lk., while in the lowert part of the station P. spinosum grows on gravel with Thymelaea hirsuta Endl. P. spinosum at Calamosca has never been found growing with Thymus capitatus and Thymelaea hirsuta both. The center of the distribution area of P. spinosum is in eastern Mediterranean where it forms (Greece and Greek islands) a typical association with Thymelaea hirsuta (RIKLI 1946). In Israel P. spinosum is associated with Thymus capitatus (ZOHARY). The distribution area of P. spinosum is solid in its eastern part, fragmented in central Mediterranean and sparse towards the west. Recently the species, which has 2n = 28 chromosomes (LARSEN 1955), has been found to have hypoglycemic principles active against diabetes.  相似文献   

6.
Packera insulae-regalis (Asteraceae, Senecioneae) is a new species that is only known from one population occurring near the summit of Mount Franklin on Isle Royale, Michigan, U.S.A. It resembles both P. paupercula and P. indecora but is hexaploid, whereas the former has diploid and tetraploid populations and the latter is octoploid around the western Great Lakes. Whereas most species of Packera are self-incompatible (as is P. paupercula) and a few are self-compatible (as is P. indecora), P. insulae-regalis is unique in the genus in being partially self-compatible, as far as is known. Its origin post-glacially by hybridization between these two species is hypothesized.  相似文献   

7.
Summary E. coli [32P]-labelled 5S RNA was complexed with E. coli and B. stearothermophilus 50S ribosomal proteins. Limited T1 RNase digestion of each complex yielded three major fragments which were analysed for their sequences and rebinding of proteins. The primary binding sites for the E. coli binding proteins were determined to be sequences 18 to 57 for E-L5, 58 to 100 for E-L18 and 101 to 116 for E-L25. Rebinding experiments of purified E. coli proteins to the 5S RNA fragments led to the conclusion that E-L5 and E-L25 have secondary binding sites in the section 58 to 100, the primary binding site for E-L18. Since B. stearothermophilus proteins B-L5 and BL22 were found to interact with sequences 18 to 57 and 58 to 100 it was established that the thermophile proteins recognize and interact with RNA sequences similar to those of E. coli. Comparison of the E. coli 5S RNA sequence with those of other prokaryotic 5S RNAs reveals that the ribosomal proteins interact with the most conserved sections of the RNA.Paper number 12 on structure and function of 5S RNA.Preceding paper: Wrede, P. and Erdmann, V.A. Proc. Natl. Acad. Sci. USA 74, 2706–2709 (1977)  相似文献   

8.
Background: Prescribed burning in peatlands is controversial due to concerns over damage to their ecological functioning, particularly regarding their key genus Sphagnum. However, empirical evidence is scarce.

Aims: The aim of the article is to quantify Sphagnum recovery following prescribed burns.

Methods: We completed nine fires at a raised bog in Scotland, achieving a range of fire severities by simulating drought in some plots. We measured Sphagnum cover and chlorophyll fluorescence Fv/Fm ratio (an estimate of photosynthetic capacity) up to 36 months post-fire.

Results: Cover of dominant Sphagnum capillifolium was similar in unburnt and burnt plots, likely due to its high moisture content which prevented combustion. Burning decreased S. capillifolium Fv/Fm 5 months after fire from 0.67 in unburnt plots to 0.44 in low fire severity plots and 0.24 in higher fire severity (drought) plots. After 22 months, Fv/Fm in burnt plots showed a healthy photosynthetic capacity of 0.76 and no differences between severity treatments. Other Sphagnum species showed similar post-fire recovery though their low overall abundance precluded formal statistical analysis.

Conclusions: S. capillifolium is resilient to low–moderate fire severities and the same may be true for a number of other species. This suggests that carefully applied managed burning can be compatible with the conservation of peatland ecosystem function.  相似文献   

9.
Abstract

The various stages of female gametophyte development and embryogenesis in S. spiralis and S. aestivalis are described. In both species the reproductive cycle is sexual. Some peculiarities are present: the female gametophyte is usually 6-7-8-nucleate; after double fertilization a single endospermatic cell is formed; the proembryo appears differentiated and is made up of different cells in the chalazal and micropylar ends; a single basal cell in the proembryo acts as suspensor.  相似文献   

10.
海绵来源链霉菌S52-B中氨酰胺天然产物的分离与鉴定   总被引:1,自引:0,他引:1  
【背景】海洋微生物是复杂海洋生态环境中重要的生物资源之一。海洋微生物所产生的活性天然产物极为丰富,是药物或药物先导化合物的重要来源。【目的】探索海洋中海绵来源链霉菌Streptomycessp.S52-B的优势生长条件,挖掘其次级代谢产物,以期分离具有良好生物活性的天然产物。【方法】根据"One Strain Many Compounds"(OSMAC)策略,寻找利于Streptomyces sp. S52-B生长和次级代谢产物产生的优势培养基,结合质谱及特征性的紫外吸收谱图,选择培养基进行大量发酵。利用正相硅胶柱色谱、葡聚糖凝胶柱色谱和制备型高效液相色谱等进行分离纯化,并应用高分辨质谱和核磁共振光谱进行化合物结构解析。【结果】确定培养基A–D为海洋链霉菌S52-B的优势培养基,基于紫外吸收光谱与质谱分析,从培养基A的大量发酵物中分离鉴定3个具有吡咯并[4,3,2-de]喹啉核心结构的含氯化合物,属于氨酰胺类天然产物,其中Ammosalic acid为新结构化合物。【结论】已知含有吡咯并喹啉母核的氨酰胺类家族化合物具有优良的抗癌活性。本研究从海绵来源链霉菌S52-B中分离鉴定了3个氨酰胺类化合物,其中一个是新结构化合物,不仅丰富了此类化合物家族的结构类型,也为研究其生物合成途径中的未知机理奠定了基础,还有利于结合培养条件和基因组信息从这株海绵来源链霉菌中挖掘新结构的活性天然产物。  相似文献   

11.
12.
The plasma membrane H+-ATPase pump (Pma1p) has been proposed as a viable target for antifungal drugs since this high capacity proton pump plays a critical role in the intracellular regulation of pH and in nutrient uptake of yeast and other fungi. In recent years, this and other laboratories have verified that the antifungal activity of 2-phenylbenzisoselenazol-3(2H)-one, an organoselenium compound commonly referred to as ebselen (1), stems, at least in part, from its inhibitory action on the fungal Pma1p. In the present study, the antifungal efficacy of 2-(3-pyridinyl)-benzisoselenazol-3(2H)-one (2) and 2-phenylbenzisoselenazol-3(2H)-one 1-oxide (3), two ebselen analogs, was evaluated using a strain of S. cerevisiae and compared against that of 1. In addition, the study also examined the inhibitory potential of these three compounds toward the Pma1p of S. cerevisiae. Based on mean IC50 values, the antifungal potency was found to decrease in the order 3?>?1?>?2. However, in terms of inhibitory action on Pma1p, the potency decreased in the order 1?>?3?>?2. The magnitude of these activities appears to be correlated with the corresponding log P values, with compound 2 being the most hydrophilic and the least active of the three.  相似文献   

13.
《Journal of bryology》2013,35(2):91-99
Abstract

Genetic diversity in eight populations of Sphagnum capillifolium from different Bulgarian mountains was investigated by means of isozyme electrophoresis. High levels of allelic diversity were found (HS = 0.119), comparable to earlier estimates for northern European populations (HS = 0.116). Strong differentiation among populations and a low number of widespread genotypes suggest a high degree of isolation and restricted gene flow between populations, which is consistent with generally small and scattered populations. The large proportion of distinguishable genotypes (mean 0.498) suggests high levels of out-crossing either currently or in the past. Introgression between S. capillifolium and S. rubellum, a species not found in Bulgaria, was suggested by the occurrence of rubellum-alleles in five populations from different mountains. This could be explained by an ancient hybridization event in a sympatric population. Based on (1) the high genetic diversity, (2) the fairly wide distribution of alien alleles, and (3) the isolated distribution of populations even within one mountain, a possible survival of S. capillifolium in the Balkan area during the Quaternary ice periods is hypothesized.  相似文献   

14.
《Journal of bryology》2013,35(4):301-303
Abstract

Schistidium occidentale (E. Lawton) Churchill is reported for the first time in Europe, from the Sierra Nevada (Spain). Previously it was known only from the mountains of southwestern North America. The species is illustrated, and notes are given on its distribution and ecology.  相似文献   

15.
Summary

The author describes a Sporobolus Poiretii (R. et S.) Hitchc. and Oenothera sinuata L. stand in the «Selva» (forest) of S. Rossore (near Pisa).

Earlier reports of these two adventive and perhaps naturalized species are mentioned.

The author discussues the critical and complex sistematic definition, nomenclature and sinonimy of Sporobolus Poiretii in connection with the nearly related species Sporobolus indicus R. Br.

The author prospects at the end how both Sp. Poiretii and Oe. sinuata can be inserted in the «Nuova Flora Analitica» of Italy, by Adriano Fiori.  相似文献   

16.
Two new species, Elaphoglossum alvaradoanum and E. pendulum, are described. The first species is endemic to Cocos Island, and the second to the mountains of Costa Rica. Elaphoglossum auripilum var. longipilosum is elevated to species rank as E. longipilosum.  相似文献   

17.
The ant genus Solenopsis Westwood 1840, is recorded for the first time in Saudi Arabia. The worker caste of S. saudiensis n. sp., collected in Riyadh is described and illustrated. This resembles S. cooperi Donisthorpe 1947, and S. kochi Finzi 1936. A revised key to the Arabian species is given together with ecological and biological notes. S. saudiensis n. sp. is identified by the following characters: Anterior clypeal margin with a central pair of stout projecting teeth and a lateral pair of short, broad basal blunt teeth; eyes with two minute facets; funicular segments 2–7 about twice as wide as long; propodeum short and low with the basal face making a continuous arc with the declivity; and petiole as long as broad in dorsal view.  相似文献   

18.
Summary Six newSalmonella types isolated in Ghana are described.S. volta, 11: 4: 1,z13, z28 was isolated from a swine;S.agona 4,12: fgs:—,S.wa, 16: b: 1,5S.technimani, 28: c: z6 andS.tafo, 1, 4 12, 27: z35: 1,7 were isolated from cattle;S.mampong, 13,22: z35: 1,6, was isolated from a lizzard.  相似文献   

19.
(S)-1,4-benzodioxan-2-carboxylic acid-1 is used as starting compound for the production of the more effective (S) enantiomer of the drug doxazosin mesylate. The catalytic ability of some commercial lipases for preparations of (S) enantiomer of 1 from (±) methyl 1,4-benzodioxin-2-carboxylate-2 is reported. Lipases from bacterial sources were more successful in resolving the ester than those from the yeast lipases. About 85% enantiomerically pure ester was achieved by lipase from alcaligenes sp.  相似文献   

20.
[目的]研究(S)-雌马酚对人体肠道菌群的体外调控作用和人体肠道菌群对(S)-雌马酚的代谢衍生作用。[方法]采用人体肠道菌群体外批量发酵、细菌16S rRNA基因高通量测序、气相色谱、液相色谱和质谱等检测(S)-雌马酚与人体肠道菌群体外相互作用。[结果]体外添加(S)-雌马酚对总体人肠道菌群结构和短链脂肪酸产量影响不明显。添加0.45 mmol/L (S)-雌马酚组与对照组相比,未检测到相对丰度发生显著变化的细菌;添加0.90 mmol/L (S)-雌马酚组与对照组相比,显著增加了肠杆菌科(Enterobacteriaceae)等条件致病菌的相对丰度,减少了潜在益生菌粪球菌属(Coprococcus)的比例。代谢分析发现,发酵培养液中(S)-雌马酚的浓度降低了约15%−30%,推测可能被微生物进一步降解或衍生修饰。[结论]从体外调控肠道菌群的角度判断,0.45 mmol/L (S)-雌马酚相对较安全,而0.90 mmol/L (S)-雌马酚可能会破坏肠道菌群平衡。(S)-雌马酚可以被人体肠道菌群进一步代谢,其特定代谢产物的结构与功能及其体内生物安全性有待进一步研究。  相似文献   

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