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1.
以2年生西伯利亚白刺、齿叶白刺和唐古特白刺苗为材料,设置0、100、200、300、400 mmol.L-1NaCl 5种盐浓度开展胁迫试验,测定并对比分析其对盐胁迫的生长及生理生化响应。结果表明:低盐浓度处理促使白刺生长速度和生物量增加、叶绿素含量增高,高盐浓度处理下这种促进作用降低;在100 mmol.L-1的盐处理下,唐古特白刺、西伯利亚白刺、齿叶白刺叶绿素含量均达最高,分别为0.72、0.78、0.61 mg.g-1;在400 mmol.L-1的盐处理下,唐古特白刺、西伯利亚白刺、齿叶白刺生物量为最低,分别为10.49、12.42、10.19 g.株-1,仅为对照的75%79%;3种白刺中,唐古特白刺的Na+/K+最高,施盐处理下西伯利亚白刺的Na+/K+均高于对照,而齿叶白刺则低于对照;随着盐浓度的增加,3种白刺叶片中可溶性蛋白的含量递增,可溶性糖含量则先增后减;低盐浓度处理的唐古特和西伯利亚白刺叶片中MDA含量比对照低,齿叶白刺却比对照高;3种白刺的POD和SOD活性在盐处理下高于对照,其中唐古特白刺叶片中POD活性最低,齿叶白刺中SOD活性最高;3种白刺在盐胁迫下均能正常生长。 相似文献
2.
Objectives
Jatropha tanjorensis was investigated scientifically to generate evidence for the efficacies reported in traditional systems and the results are given here.Methods
Different concentrations of the solvent extracts of leaves and four isolated compounds were tested against human pathogenic microorganisms such as gram-positive bacteria of Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermis, gram-negative bacteria of Aeromonas hydrophila, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Proteus vulgaris, Salmonella paratyphi, Salmonella paratyphi A, Vibrio alcaligenes, Vibrio cholerae and fungi of Aspergillus fumigatus, Candida albicans, Microsporum gypseum and Trichophyton rubrum by agar-well diffusion and disk diffusion methods.Results
In agar-well diffusion method, maximum activity was recorded in a concentration-dependent manner. The extracts recorded activity against bacteria such as 17–26, 15–25 and 13–24 mm to methanol extract and 15–24, 14–23 and 12–22 mm to chloroform extract at 50, 25 and 12.5 mg/ml respectively and fungi such as 9–15 mm to A. fumigatus and 5–16 mm to T. rubrum. Maximum activity was 30–46, 27–43 and 17–40 mm to friedelin and 23–46, 28–44 and 18–41 mm to R (+) 4-hydroxy-2-pyrrolidinone against bacteria and 12–37, 8–34 and 31–33 mm to friedelin and 12–40, 11–35 and 10–33 mm to R (+) 4-hydroxy-2-pyrrolidinone against fungi at 10, 5 and 2.5 mg respectively.Conclusions
The present study concludes that friedelin, β-amyrin, stigmasterol and R (+) 4-hydroxy-2-pyrrolidinone present in the methanol extract could be responsible for the broad spectrum of antimicrobial activity and provide scientific evidence. 相似文献3.
E. Opuni-Frimpong D.F. Karnosky A.J. Storer E.A. Abeney J.R. Cobbinah 《Forest Ecology and Management》2008
We examined the relative susceptibility of four mahogany species, Khaya ivorensis, Khaya anthotheca, Entandrophragma angolense, and E. utile, to Hypsipyla robusta attack. Seeds were obtained from one to three parent trees for each species. The research was conducted in the moist semideciduous forest zone in Ghana and used a randomized complete block design. Tree height and diameter and height to first branch were measured until 24 months after out-planting in the field. H. robusta damage was assessed by counting the numbers of shoots attacked, branches, and dead shoots. Khaya spp. grew better but experienced more attack than Entandrophragma spp. The relative susceptibility to H. robusta attack, from most to least, of the four species was: K. anthotheca > K. ivorensis > E. angolense > E. utile. At 24 months, the mean number of shoots attacked per tree ranged from 1.0 for an E. utile seed source to 3.6 on for a K. anthotheca seed source. At 15 months, K. anthotheca and K. ivorensis started branching at about 1.5 m, but height of clear trunk increased over time due to self-pruning. As K. anthotheca grew taller, the number of H. robusta attacks per tree declined. This suggested that selection of genotypes and species that are tolerant of H. robusta attack based on infestation of young plants may not be appropriate. Genetic factors more completely reflecting the response of different species and genotypes to H. robusta attack may manifest themselves at later growth stages. 相似文献
4.
Polygonum cuspidatum root has been traditionally used for the treatment of dental diseases in Korea. The purpose of this study was to evaluate effects of P. cuspidatum root on the development of dental caries, especially its effects against bacterial viability and caries-inducing factors of Strptococcus mutans and Strptococcus sobrinus. Among methanol extract of P. cuspidatum root and its fraction tested, ethyl acetate fraction, composed of polydatin, resveratrol, anthraglycoside B, and emodin, showed inhibitory effects on glycolytic acid production and glucosyltransferase activity of S. mutans and S. sobrinus in addition to antibacterial activities. 相似文献
5.
毛竹(Phyllostachys edulis(Carr.)H.de Lehaie)作为我国最主要的经济和生态竹种[1-6],其养分管理和丰产培育技术一直是重要研究内容[7-12];然而,由于毛竹大小年和异龄结构等特点,迄今丰产经营的毛竹林肥培仍多凭经验,施肥量和肥培重点对象不明确,极易造成养分流失、肥力降低和环境污染.为此,近年来作者及课题组成员从毛竹生长发育规律出发,系统研究了自冬笋到竹材成熟采伐整个生长(经营)期毛竹生长和养分积累规律.冬笋是毛竹的第一生长阶段[13],其生长和营养状况直接决定着来年林分产量和经济效益[14]. 相似文献
6.
Various solvent extracts of Loranthus micranthus exhibited varying degrees of antimicrobial activity. Only the petroleum ether extract showed antifungal activity. The methanol extract showed the best antimicrobial activity against Escherichia coli and Bacillus subtilis. 相似文献
7.
This work deals with the evaluation of in vitro antioxidant, DNA preventing and antiamoebic activities of the water extracts of Teucrium polium and Stachys iberica. In all systems, T. polium extract exhibited excellent activity potential than that of S. iberica. The amount of total phenolics and flavonoids were high in this extract. In the presence of 40 mg/ml T. polium extract, a significant protection was observed for native super coiled DNA of pBR322 plasmid DNA. In the presence of 32 mg/ml of T. polium extract, no trophozoite was after the 24th hour. 相似文献
8.
Six flavonol glycosides, compounds 1-3 from A. burnatii Gáyer and 4-6 from A. variegatum L., were obtained from their methanol extracts of aerial parts. The identified structures were quercetin 3-O-β-d-glucopyranoside-7-O-(6-E-p-coumaroyl)-β-d-glucopyranosyl-(1 → 3)-α-l-rhamnopyranoside (1), quercetin 3-O-β-d-glucopyranoside-7-O-β-d-glucopyranosyl-(1 → 3)-α-l-rhamnopyranoside (2), quercetin 3-O-β-d-glucopyranoside-7-O-(6-E-caffeoyl)-β-d-glucopyranosyl-(1 → 3)-α-l-rhamnopyranoside (3), kaempferol 3-O-β-d-galactopyranoside-7-O-α-l-arabinopyranoside (4), quercetin 3-O-β-d-glucopyranoside (5), and kaempferol 3-O-β-d-glucopyranoside (6). Compounds 1, 2 and 4 were isolated for the first time. The antioxidant potential of the methanol extracts and pure compounds was tested with different assays. 相似文献
9.
测定了椽竹竹材的理化性质,并与毛竹、青皮竹和绿竹竹材进行了比较分析.结果表明:椽竹各竹龄竹材的基本密度、气干密度和全干密度平均值分别为0.523～0.632 g·cm-3、0.656～0.801 g·cm-3和0.658～0.777 g·cm-3,随着竹龄增长各部位竹材密度表现出增大的趋势,3年生以上椽竹竹材基本密度小于参比竹种毛竹和青皮竹,大于绿竹.3年生以上椽竹竹材的平均气干体积于缩率和全干体积干缩率分别为9.6％和13.6％,大于毛竹;各竹龄椽竹竹材径向干缩率大于弦向干缩率和纵向干缩率.3年生以上椽竹竹材的灰分平均含量小于绿竹和青皮竹,酸不溶木素平均含量与青皮竹接近而小于绿竹,综纤维素含量大于80％,多戊糖、热水抽出物、1％NaOH抽出物平均含量均高于青皮竹和绿竹,而苯-醇抽出物平均含量小于青皮竹和绿竹.综合分析,椽竹作为纸浆材具有较高的利用价值. 相似文献
10.
Three new flavanes and eight known flavonoids were isolated from the fruits of Livistona chinensis. The structure of the new flavanes were established as 2S,3S-3,5,7,3′,5′-pentahydroxyflavane (1), 2R,3R-3,5,6,7,8,4′-hexahydroxyflavane (2) and 2R,3R-3,5,6,7,8,3′,5′-heptahydroxyflavane (3), respectively, on the basis of chemical and spectroscopic data. The antiproliferative activity against four human tumor cell lines (HL-60, Mata, HepG2 and CNE-1) was evaluated. 1 had significantly antiproliferative effects against HL-60 and CNE-1 with the IC50 of 0.2 ± 0.01 and 1.0 ± 0.1 μM, respectively, overpowering the reference compound in the assay (cisplatin). Most compounds also exhibited potent antioxidant activity. 相似文献
11.
Phytochemical investigation of the ethanol extract of the leaves of Andrographis paniculata yielded one novel diterpene (13R, 14R) 3, 13, 14, 19-tetrahydroxy-ent-labda-8 (17), 11-dien-16, 15-olide 1 which has an uncommon cis-diol groups in the lactone moiety, and 3, 19-isopropylidene-14-deoxy-ent-labda-8 (17), 13-dien-16, 15-olide 2, probably an artifact diterpene, together with eight known diterpenoids 3–10. The structures of these compounds were determined on the basis of spectral methods. The structure and stereochemistry of 1 was confirmed by X-ray crystallographic analyses. 相似文献
12.
13.
The tender leafstalks of Ledum palustre var.dilatatum were used as explants for the experiment.Uniform design for the most suitable media for shoots regeneration immediately at base of tender leafstalks,rooting and germplasm conservation in vitro was screened.The results showed that N6+ZT 2.65 mg·L-1+IAA 0.05 mg·L-1 was fits for shoots regeneration,the frequency of shoots induction was higher than 92.5%;MS(modified)+IAA 0.1 mg·L-1+Kt 0.75 mg·L-1 for rooting,the rate of rooting was 98%;N-68+B9 2.5 mg·L-1+ Ph... 相似文献
14.
Data on tree biomass are essential for understanding the forest carbon cycle and plant adaptations to the environment. We determined biomass accumulation and allometric relationships in the partitioning of biomass between aboveground woody biomass, leaves and roots in Nothofagus antarctica. We measured above- and belowground biomass of N. antarctica trees across different ages (5–220 years) and crown classes (dominant, codominant, intermediate and suppressed) in three site qualities. The biomass allocation patterns were studied by fitting allometric functions in biomass partitioning between leaves (ML), stem and branches (MS) and roots (MR). These patterns were tested for all pooled data and according to site quality and crown classes. Biomass accumulation varied with crown class and site quality. The root component represented 26–72% of the total biomass depending on age and site. N. antarctica scaling exponents for the relationships MLvs. MS, MAvs. MR, and MSvs. MR were close to those predicted by the allometric biomass partitioning model. However, when biomass allocation was analyzed by site quality the scaling exponents varied following the optimal partitioning theory which states that plants should allocate more biomass to the part of the plant that acquires the most limiting resource. In contrast, the crown class effect on biomass partitioning was almost negligible. In conclusion, to obtain accurate estimations of biomass in N. antarctica trees the allometric approach appears as an useful tool but the site quality should be taken into consideration. 相似文献
15.
Li HE Qiu JZ Yang ZQ Dong J Wang JF Luo MJ Pan J Dai XH Zhang Y Song BL Deng XM 《Fitoterapia》2012,83(1):241-248
In the present study, the antimicrobial activity of glycyrrhetinic acid (GA) against Staphylococcus aureus, and its influence on the production of S. aureus alpha-haemolysin (Hla) were investigated, along with the in vivo activity of GA against S. aureus-induced pneumonia. GA could not inhibit the growth of S. aureus, but the secretion of Hla by S. aureus was significantly inhibited by low concentrations of GA in a dose-dependent manner. Furthermore, in vivo data show that GA provides protection against staphylococcal pneumonia in a murine model system. 相似文献
16.
Gloria María Molina-Salinas Jorge Bórquez Alejandro Ardiles Salvador Said-Fernández Luis Alberto Loyola Aurelio San-Martín Isidro González-Collado Luis Manuel Peña-Rodríguez 《Fitoterapia》2010
The antituberculosis activity of 14 natural azorellane and mulinane diterpenoids isolated from Azorella compacta, Azorella madreporica, Mulinum crassifolium, and Laretia acaulis, together with eight semisynthetic derivatives, was evaluated against two Mycobacterium tuberculosis strains. The natural azorellanes azorellanol (3) and 17-acetoxy-13-α-hydroxyazorellane (6), and the semisynthetic mulinanes 13-hydroxy-mulin-11-en-20-oic-acid methyl ester (13) and mulinenic acid methyl ester (23), showed the strongest activity, with MIC values of 12.5 μg/mL against both strains. The methylated derivatives 13-hydroxy-mulin-11-en-20-oic-acid methyl ester (13), mulin-11,13-dien-20-oic acid methyl ester (15) and mulinenic acid methyl ester (23) proved to be more active than the parent compounds. 相似文献
17.
白蜡虫对低温的高度耐受性对其生存、繁殖及白蜡生产都至关重要。为探讨低温胁迫对白蜡虫hsp表达的影响,采用实时荧光定量PCR（qRT-PCR）,对白蜡虫二龄雄虫在低温胁迫下7个不同的 hsps（hsp21.5,hsp21.7,hsp40,hsp60,hsp70,hsc70,hsp90）的基因表达情况进行了检测。结果发现,除hsc70外,其余hsps均能被低温不同程度地诱导,其中hsp70、hsp21.7和hsp90的上调量十分显著。说明多数hsps都与白蜡虫幼虫应对低温胁迫相关。 相似文献
18.
Areej Mohammad Al-Taweel Shagufta Perveen Ghada Ahmed Fawzy Saleh Ibrahim Alqasoumi Kamal E.H. El Tahir 《Fitoterapia》2012
Two new flavane gallates were isolated from the leaves of Plicosepalus curviflorus. The structure of the new compounds was established as 2S,3R-3,3′,4′,5,7-pentahydroxyflavane-5-O-gallate (1) and 2S,3R-3,3′,4′,5,5′,7-hexahydroxyflavane-4′,5-di-O-gallate (2), respectively. In addition, seven known compounds (−)-catechin (3), quercetin (4), lupeol (5), β-sitosterol (6), pomolic acid (7), β-sitosterol 3-O-β-d-glucopyranoside (8) and 4-methoxycinnamic acid (9) were reported for the first time from the genus Plicosepalus. Compounds 1, 2 and 3 were investigated for their hypoglycemic activity and showed significant hypoglycemic activity in Swiss Albino mice. 相似文献
19.
Han Y.H. Chen Stan Vasiliauskas Gordon J. Kayahara Triin Ilisson 《Forest Ecology and Management》2009
Postfire tree species compositions are predicted to be the same prior to fire according to the direct regeneration hypothesis (DRH). We studied 94 upland boreal forest stands between 5 and 18 years after fire in Ontario, Canada. Postfire species-specific regeneration density was positively related to prefire stand basal area for Pinus banksiana, Populus spp., Betula papyrifera and Picea mariana, but not for Picea glauca and Abies balsamea. In addition, seedling density of Populus spp., B. papyrifera, P. mariana, P. glauca and A. balsamea were positively affected by build up index and, except Populus spp., their density increased with age of burn. To facilitate testing the DRH, we introduced a term called compositional difference (CD) that is the difference in a species relative percentage between the postfire and prefire stand. The testable null hypothesis is CD = 0 for a given species. CD was not different from 0 for P. banksiana, was 19.8% for Populus spp., 10.4% for B. papyrifera, −17.9% for P. mariana, −14.6% for P. glauca, and −14.9% for A. balsamea, indicating fire increases broadleaves at the expenses of mid- and late-successional coniferous species. Compositional increases of Populus spp. and B. papyrifera in postfire stands occurred mostly where these species were a minor component prior to fire. In conclusion, the DRH was supported by the specific positive relationships between postfire regeneration densities and prefire basal area for P. banksiana, Populus spp., B. papyrifera and P. mariana. However, if the DRH is used for predicting postfire composition, P. banksiana is the only species that had the same composition between postfire and prefire stands. Nevertheless, CD for P. banksiana was negatively related to its prefire composition. Similarly, CD for other species was negatively related to their prefire compositions with varying effects of build up index and age of burn. Our results suggest, if fire occurrences increase with global change, the boreal landscape will be more dominated by hardwoods and mixtures of conifers and hardwoods. 相似文献
20.
对混合菌液诱导和非诱导处理的喙尾琵甲幼虫抗菌肽进行了分离纯化及抑菌活性比较。结果显示:诱导组和非诱导组粗提物无抑菌活性,但是经凝胶色谱分离后,从非诱导组获得组分DZP1,对金黄色葡萄球菌、枯草芽孢杆菌表现出抑制作用;从诱导组获得组分YDP1,对金黄色葡萄球菌、枯草芽孢杆菌、绿脓杆菌具有活性,且YDP1活性明显强于DZP1;Tricine-SDS-PAGE检测表明DZP1和YDP1组成、种类基本一致,主要由20 kD以下分子量的小肽组成。研究结果表明:喙尾琵甲幼虫在诱导和非诱导条件下均可分离到具有抑菌活性的抗菌肽,菌液诱导可增强抗菌肽的活性和抑菌谱。 相似文献