首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
An ethanol extract of the aerial parts of Delphinium gracile DC. yielded five flavonol glycosides quercetin-3-O-{[β-d-xylopyranosyl (1 → 3)-4-O-(E-p-caffeoyl)-α-l-rhamnopyranosyl (1 → 6)][β-d-glucopyranosyl (1 → 2)]}-β-d-glucopyranoside (1), quercetin-3-O-{[β-d-xylopyranosyl (1 → 3)-4-O-(E-p-coumaroyl)-α-l-rhamnopyranosyl (1 → 6)][β-d-glucopyranosyl (1 → 2)]}-β-d-glucopyranoside (2), quercetin-3-O-{[β-d-xylopyranosyl (1 → 3)-4-O-(Z-p-coumaroyl)-α-l-rhamnopyranosyl (1 → 6)][β-d-glucopyranosyl (1 → 2)]}-β-d-glucopyranoside (3), kaempferol-3-O-{[β-d-glucopyranosyl (1 → 3)-4-O-(E-p-coumaroyl)-α-l-rhamnopyranosyl (1 → 6)][β-d-glucopyranoside-7-O-(4-O-acetyl)-α-l-rhamnopyranoside (4) kaempferol-3-O-{[β-d-glucopyranosyl (1 → 3)-4-O-(E-p-coumaroyl)-α-l-rhamnopyranosyl (1 → 6)][β-d-glucopyranoside-7-O-(4-O-acetyl)-α-l-rhamnopyranoside (5) in addition to 4-(β-d-glucopyranosyloxy)-6-methyl-2H-pyran-2-one (6) and rutin. Structures were elucidated by spectroscopic methods.  相似文献   

2.
The determination of phenotypic and genotypic traits of a group of closely related Vibrio strains from the Baltic Sea did not allow species designation. DNA-DNA hybridization and fatty acid analysis revealed them as Vibrio navarrensis. Therefore we suggest these Vibrios to represent a new biotype, named V. navarrensis biotype pommerensis.  相似文献   

3.
Bacterial strains from inoculated soybean field soil in Thailand were directly isolated using Bradyrhizobium japonicum selective medium (BJSM), on the basis of Zn2+ and Co2+ resistance of B. japonicum and B. elkanii. The isolates were classified into symbiotic and non-symbiotic groups by inoculation assays and Southern hybridization of nod and nif genes. In this study, a nearly full-length 16S rRNA gene sequence showed that the non-symbiotic isolates were more closely related to members of Rhodopseudomonas and to a number of uncultured bacterial clones than to members of Bradyrhizobium. Therefore, a polyphasic study was performed to determine the taxonomic positions of four representatives of the non-symbiotic isolates. Multilocus phylogenetic analysis of individual genes and a combination of the 16S rRNA and three housekeeping genes (atpD, recA and glnII) supported the placement of the non-symbiotic isolates in a different genus. The ability of heavy metal resistance in conjunction with phenotypic analyses, including cellular fatty acid content and biochemical characteristics, showed that the non-symbiotic isolates were differentiated from the other related genera in the family Bradyrhizobiaceae. Therefore, the non-symbiotic isolates represented a novel genus and species, for which the name Metalliresistens boonkerdii gen. nov., sp. nov. is proposed. The type strain is NS23 (= NBRC 106595T = BCC 40155T).  相似文献   

4.
Ferret-badgers, genus Melogale, are distributed in the Indochinese region, Java, Bali and NE-Borneo. There are currently four species described each having very similar phenotypes. In March 2005, a living ferret-badger of a different phenotype was confiscated by rangers from Cuc Phuong National Park, Vietnam. This individual died and the carcass was not preserved. In January 2006, a newly deceased individual of the same phenotype was found at the Endangered Primate Rescue Center, Cuc Phuong National Park. Due to several different characteristics these individuals vary greatly from the current species. Thus, we describe an additional species, M. cucphuongensis sp. nov. from northern Vietnam, which occurs sympatrically with M. moschata and M. personata, but differs from both species clearly in skull morphology and other features.Based on a 423 bp-long fragment of the mitochondrial cytochrome b gene, M. cucphuongensis sp. nov. is a member of the genus Melogale and represents a sister lineage to a clade consisting of M. personata and M. moschata.  相似文献   

5.
6.
7.
A water-soluble polysaccharide was extracted with alkali from the cell wall of Verticillium lecanii (also called Lecanicillium lecanii). After freezing and thawing, the water-soluble fraction was purified by gel filtration chromatography on Sepharose CL-6B and eluted as one peak by HPSEC/RID. Monosaccharide analysis showed galactose and glucose (1.1:1), with traces of mannose (<1%). The structural characteristics were determined by spectroscopic analysis, FT-IR and 1D and 2D 1H and 13C NMR, and methylation results. On the basis of the data obtained, the following structure of the polysaccharide (E3SIV fraction) was established:  相似文献   

8.
In many coastal and estuarine areas the planktonic copepods Acartia tonsa and Acartia clausi show a spatial separation with A. tonsa restricted to brackish waters and confined environments and A. clausi inhabiting areas more influenced by sea water. The hatching and viability of A. tonsa and A. clausi eggs exposed to anoxia and anoxia/sulfide (conditions that are frequent in bottom waters of the most confined areas) was evaluated to determine if these stress factors play a role in the distribution of these species. Subitaneous eggs, spawned by laboratory reared organisms, were incubated in near anoxia (< 7.59 × 10− 3 mmol O2 L− 1) or anoxia/sulfide (∼ 1 mmol L− 1) for different periods (1, 4, 8 and 15 days), then transferred to normoxic conditions. The exposure of the eggs to near anoxia and sulfide appears to induce the same response (quiescence) in both species. Exposure times ≤ 8 days to near anoxia or anoxia/sulfide did not affect egg viability, while 15 day exposure caused significant declines in hatching success of both species. A significant difference between the effects of near anoxia and anoxia/sulfide was observed when incubation lasted 15 days; hatching of eggs exposed to sulfide being higher than that of eggs exposed to near anoxia for both species. No significant differences were observed between the two species in hatching success of eggs exposed to both near anoxia and anoxia/sulfide (with the exception of eggs incubated in near anoxia for 4 days). The results indicate that the impact of anoxia and sulfide on the eggs of the two Acartia species cannot be a factor explaining the spatial distribution in coastal and brackish environments of these copepods.Feeding experiments on A. clausi were also performed. Suitability of different algal species to rear this copepod was evaluated and the results were compared with data previously obtained for A. tonsa. Differences in feeding needs between A. clausi and A. tonsa are discussed.  相似文献   

9.
王学霞  王国红  戈峰 《生态学报》2011,31(3):629-637
以CO2浓度升高为作用因子,观测了连续3代饲养在转Bt基因棉(GK-12)和亲本棉泗棉3号(S3)上B型烟粉虱的个体大小、解毒酶活性及第3代烟粉虱的选择性和产卵量。结果表明,CO2浓度和棉花品种处理对第2、3代烟粉虱卵长、伪蛹大小、雌雄成虫大小的影响均不显著,但CO2浓度升高使第1代烟粉虱的伪蛹长、雌虫翅展和雌、雄虫长显著低于对照CO2浓度下生长的烟粉虱;取食S3的伪蛹长、雌虫长和雌虫翅展分别比相应的对照浓度下的低2.81%、2.95%、0.94%,取食GK-12的雌虫翅展和雄虫长均比相应的对照浓度下的低2.08%和2.58%。3种解毒酶的活性测定显示,取食高CO2浓度处理的转基因棉GK-12上的F3代烟粉虱的谷胱甘肽S转移酶(Glutathione Stransferase, 简称GSTs)活性和取食亲本棉S3的F1代的乙酰胆碱酯酶(Acetylcholinesterase;简称AchE)的活性分别比对照处理的增加45.73%和27.68%;而羧酸酯酶(Carboxylic Ester hydrolase;简称 CarE)在取食4个处理的棉花上烟粉虱的活性均无显著的差异;而取食对照CO2条件下GK-12棉花的F1代烟粉虱GSTs活性比取食S3棉花低35.12%。对3个因子的交互分析结果显示,C02浓度对3种酶活影响均不显著,品种对GSTs的影响显著,世代、CO2×品种及CO2×品种×世代间的交互作用对AchE酶活影响显著,各因子对CarE的活性影响均不显著。烟粉虱的选择实验结果表明,4种处理的F3代B型烟粉虱均喜好选择在高CO2处理的棉花,而且选择高CO2处理的GK-12的数量多于其他3个处理,其中对照浓度下生长的烟粉虱选择高CO2的GK-12比高CO2处理的S3、对照浓度处理的GK-12 和S3分别增加9.175%, 19.89%、27.93%; 而高浓度下生长的烟粉虱选择高CO2的GK-12比高CO2处理的S3、对照浓度处理的GK-12 和S3分别增加12.56%,21.05%,28.73%。72h的产卵量检测发现,烟粉虱在高CO2处理的2种棉花上的产卵量也是多于对照条件下的棉花,对照条件下的棉花相比,高CO2和对照浓度下生长的烟粉虱的在高CO2处理的2种棉花上的产卵量分别增加24.55%和19.03%;在高CO2浓度下生长的F3代烟粉虱更喜好在高CO2浓度处理的GK-12上产卵,与对照浓度下的GK-12相比增加26.93%,差异达到显著水平。  相似文献   

10.
Flavobacteria are abundant in the North Sea, an epeiric sea on the continental shelf of Europe. However, this abundance has so far not been reflected by the number of strains in culture collections. In this study, Flavobacteria were isolated from pelagic and benthic samples, such as seawater, phytoplankton, sediment and its porewater, and from surfaces of animals and seaweeds on agar plates with a variety of carbon sources. Dilution cultivation with a new medium, incubation at low temperatures and with long incubation times, and colony screening by a Flavobacteria-Cytophagia-specific PCR detecting 16S rRNA gene sequences led to a collection of phylogenetically diverse strains. Two strains affiliated with Flammeovirgaceae and seven strains affiliated with Cyclobacteriaceae, whereas within the Flavobacteriaceae 20 isolated strains presumably represented seven novel candidate genera and 355 strains affiliated with 26 of 80 validly described marine Flavobacteriaceae genera, based on a genus boundary of 95.0% 16S rRNA gene sequence identity. The majority of strains (276) affiliated with 37 known species in 16 genera (based on a boundary of 98.7% 16S rRNA gene sequence identity), whereas 79 strains likely represented 42 novel species in 22 established Flavobacteriaceae genera. Pigmentation, iridescence, gliding motility, agar lysis, and flexirubin as a chemical marker supported the taxonomy at the species level. This study demonstrated the culturability on solid medium of phylogenetically diverse Flavobacteria originating from the North Sea.  相似文献   

11.
Four red-pigmented isolates, with optimum growth temperatures of approximately 55–60 °C and an optimum pH for growth between 7.5 and 8.5, were recovered from hot springs in Central France. Phylogenetic analysis of the 16S rRNA gene sequences showed that these organisms represented a new species of the genus Meiothermus. The new isolates could be distinguished from other strains of the species of the genus Meiothermus primarily by the glycolipid profile and fatty acid composition because these organisms lacked the hydroxy fatty acids and the glycolipid variant GL-1a found in all other isolates of the species of Meiothermus examined. On the basis of the results presented here we propose the name Meiothermus rufus for the new species, which is represented by strains CAL-4T (=DSM 22234T=LMG 24878T) and CAL-12 (=DSM 22235=LMG 24879). We also propose emending the genus Meiothermus to include strains that have only one glycolipid instead of two glycolipid variants.  相似文献   

12.
13.
于基成  刘秋  邵阳  刘长建  闫建芳  齐小辉 《生态学报》2014,34(20):5896-5906
以大肠杆菌、金黄色葡萄球菌和尖孢镰刀枯萎病菌作为测试靶目标,采用9种分离培养基从大连海域13个不同采样点的海洋沉积物样品中分离到165株海洋链霉菌。从165株海洋放线菌中筛选到对金黄色葡萄球菌具有抑制活性的菌株85株,占总菌株数的51.5%;对大肠杆菌具有抑制活性的菌株27株,占总菌株数的16.4%;对尖孢镰刀枯萎病菌具有抑制活性的菌株仅有6株,占总菌株数的3.6%。因此,海洋链霉菌的活性更多地表现为对细菌的抗性,尤其对革兰氏阳性细菌具有更高的抑制活性。对其中具有抑制活性或形态独特的菌株进行了16S r DNA序列分析,并构建系统发育树,显示活性海洋链霉菌具有丰富的种类多样性和广谱抗菌活性。同种海洋链霉菌与土壤链霉菌活性比较结果也表明,海洋链霉菌多表现抗革兰氏阳性细菌活性。  相似文献   

14.
15.
16.
Two red-pigmented isolates, with optimum growth temperatures between 45 and 50 °C, were recovered from a hot spring in the Furnas, Área da Fonte 1825 on the Island of São Miguel in the Azores. Phylogenetic analysis of the 16S rRNA gene sequences showed that these organisms represented a new species of the genus Meiothermus. These new isolates could be distinguished from other strains of the species of the genus Meiothermus primarily by the fatty acid composition and polar lipid pattern, since they did not possess 2-OH fatty acids or glycolipid variant GL-1a. Moreover, the two new isolates had the lowest growth temperature range of any of the known species of the genus Meiothermus. On the basis of the results presented here we propose the name Meiothermus granaticius for the new species represented by strains AF-68T (=DSM 23260T = LMG 25524T) and AF-49 (=DSM 23259 = LMG 25525).  相似文献   

17.
The oomycete genus Aquastella is described to accommodate two new species of parasites of rotifers observed in Brooktrout Lake, New York State, USA. Three rotifer species – Keratella taurocephala, Polyarthra vulgaris, and Ploesoma truncatum – were infected, and this is the first report of oomycete infection in these species. Aquastella attenuata was specific to K. taurocephala and Aquastella acicularis was specific to P. vulgaris and P. truncatum. The occurrence of infections correlated with peak host population densities and rotifers were infected in the upper layers of the water column. Sequencing of 18S rRNA and phylogenetic analysis of both species placed them within the order Saprolegniales, in a clade closely related to Aphanomyces. The Aquastella species were morphologically distinct from other rotifer parasites as the developing sporangia penetrated out through the host body following its death to produce unique tapered outgrowths. Aquastella attenuata produced long, narrow, tapering, finger-like outgrowths, whilst A. acicularis produced shorter, spike-like outgrowths. We hypothesize that the outgrowths serve to deter predation and slow descent in the water column. Spore cleavage was intrasporangial with spore release through exit tubes. Aquastella attenuata produced primary zoospores, whereas A. acicularis released spherical primary aplanospores, more typical of other genera in the Aphanomyces clade.  相似文献   

18.
19.
20.
不同番茄材料对B型烟粉虱个体发育和繁殖能力的影响   总被引:1,自引:0,他引:1  
以甘蓝寄主上连续繁殖多代后的B型烟粉虱为对象,对其在8种番茄材料(4个栽培番茄、3个多毛番茄和1个醋栗番茄)上的产卵量、体型大小、发育历期、存活率以及第2代成虫的产卵量和寿命等生物学参数进行观察.自然情况下(10:00-14:00)接虫,烟粉虱在多毛番茄LA2329上的平均产卵量显著低于栽培番茄9706上的产卵量(分别为11粒,164粒).羽化后,烟粉虱雌虫在多毛番茄LA1777上的寿命显著低于在栽培番茄Moneymaker上的存活寿命(分别为5d,22d);而羽化后雌虫在LA1777上的平均产卵量显著低于在栽培番茄早粉2号上的产卵量(分别为7粒/头,95粒/头).在其他参数,如体型大小、存活率、发育历期等,没有显著性的变化.结果显示,较多毛番茄而言,栽培番茄是烟粉虱的较好寄主.而且,在评价抗烟粉虱番茄材料时,平均产卵量、羽化后雌虫寿命及产卵量是3个有效的评价参数.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号