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排序方式: 共有123条查询结果,搜索用时 711 毫秒
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Matheus H. O. de Sousa Jessica M. S. Morgan Karina Cesca Adriana Flach Neusa F. de Moura 《化学与生物多样性》2020,17(2)
The Cunila angustifolia essential oil was obtained from fresh leaves by hydrodistillation and analyzed by GC‐FID and GC‐MS to determine its chemical composition. The essential oil presented pulegone (29.5 %) and isomenthol (27.0 %) as major components, and other compounds such as menthone (8.6 %), neomenthol (7.2 %), menthyl acetate (2.5 %) and caryophyllene oxide (2.0 %) were identified. The cytotoxic activity of the essential oil was evaluated by MTS assay, with the human cancer cell lines of the lung (A549), breast (MCF‐7) and skin melanoma (SK‐Mel‐28). The assay showed the highest selectivity, to MCF‐7 cell lines, with IC50 equal to 34.0 μg mL?1, low selectivity for SK‐Mel‐28 cell lines, with IC50 equal to 279.9 μg mL?1, and no mortality to A549 cell lines. 相似文献
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ELVIA J. MELÉNDEZ‐ACKERMAN 《Plant Species Biology》2013,28(3):224-234
Nectar robbers may have direct and indirect effects on plant reproductive success but the presence of nectar robbing is not proof of negative fitness effects. We combined census data and field experiments to disentangle the complex effects of nectar robbing on nectar production rates, pollinator behavior, pollen export, and female reproductive success of Pitcairnia angustifolia. Under natural conditions flowers were visited by four different animal species including a robber‐like pollinator and a secondary robber. Natural levels of nectar robbing ranged from 40 to 100%. Natural variation in nectar robbing was not associated with fruit set in any year whereas seed set was weakly positively associated for 1 year only. Artificial nectar robbing did not increase nectar production or concentration, did not affect the behavior of long‐billed hummingbirds, and when faced with artificially robbed flowers, these visitors behaved as secondary nectar robbers. The number of stigmas within a patch that received pollen dye analogs and the average distance traveled by these analogs were not significantly different between robbing treatments (robbed flowers versus unrobbed flowers), but the maximum distance traveled by these pollen analogs was higher when nectar robbing was not prevented. Overall, the proportion of robbed flowers on an inflorescence had a neutral effect to a weak positive effect on the reproduction of individual plants (i.e. positive association between nectar robbing and fruit set in 2002) even when it clearly changed the behavior of its most efficient pollinator potentially increasing the frequency of nectar robbing within a plant. 相似文献
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Yalcuk A 《International journal of phytoremediation》2012,14(2):114-127
This study aims to remove the macro-sized nutrients that are present in the cheese whey powder solution through the use of constructed wetland systems. For this purpose, 70% and 40% demineralized solutions of cheese whey powder were used. For both concentrations, control reactors are run in parallel with Typha angustifolia planted reactors for the duration of a 92 day period. Zeolite and gravel were used as the filling material. The planted reactor, which was fed with the 70% solution, was named as Cheese Whey Powder Solution (CWPS) 1 and its unplanted control was named CWPS 2 while the reactor, which was fed with the 40% solution, was named as CWPS 3 and its unplanted control was named CWPS 4. The removal of COD, PO4-P and NH4-N were obtained as 37.47%, 45.62%, and 68.88% in CWPS 1; 24.89%, 35.74%, and 63.15% in CWPS 2; 51.15%, 54.96%, and 64.13% in CWPS 3; and 28.35%, 23.99%, and 65.92% in CWPS 4, respectively. 相似文献
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描述了泰国雨久花属Monochoria C.Presl一新变种:窄叶鸭舌草M.vaginalis var.angustifolia G.X.Wang。该新变种与原变种鸭舌草M.vaginalis var.vaginalis都具有类似的总状花序,但前者的叶片为窄披针形,3-7×0.3-2.0cm,叶片宽长比在0.1-0.4之间,叶基部裂片最长不超过2mm,总状花序具花3-7朵,而原变种鸭舌草的叶片较宽,为卵心形或心形,4-9×2-8cm,叶片宽长比在0.5-0.95之间,叶基部裂片最长可达到2cm,总状花序 相似文献
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两种水分生态型小叶章的生理生态特征研究 总被引:2,自引:1,他引:1
通过野外调查与控制试验相结合的方法,比较研究了两种水分生态型小叶章的生理生态特征,结果表明:(1)自然条件下,小叶章沼泽化草甸群落Simpson多样性指数显著高于小叶章草甸群落,但是小叶章草甸群落中小叶章种群生物量显著高于沼泽化草甸群落;草甸小叶章的株高、节长、叶长、叶宽及叶绿素含量均显著高于沼泽化草甸小叶章;叶片干重和叶鞘干、鲜重以及叶片与叶鞘生物量分配比为沼泽化草甸小叶章较高,而茎的干、鲜重和叶片鲜重、总地上生物量及茎生物量分配比均为草甸小叶章较高,但差异均不显著.(2)在人工控制水位条件下,两种生态型小叶章种群密度差异显著,而种群高度则无显著差异;两种生态型小叶章在0 cm、20 cm水位梯度下的叶长,30 cm水位梯度下的叶宽,以及0 cm水位梯度下的叶面积均存在显著差异,沼泽化草甸小叶章个体生长指标均对水位梯度具有显著响应,而典型草甸小叶章仅叶绿素含量对水位梯度具有显著响应.研究发现,两种生态型小叶章对水位条件的敏感程度不同,不同条件下对水位梯度具有不同的响应规律. 相似文献
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The distribution of the genetic variation within and among natural populations of A. ANGUSTIFOLIA growing in different regions in Brazil was assessed at microsatellite and AFLP markers. Both markers revealed high gene diversity ( H = 0.65; AR = 9.1 for microsatellites and H = 0.27; P = 77.8 % for AFLPs), moderate overall differentiation ( RST = 0.13 for microsatellites and FST = 0.10 for AFLPs), but high divergence of the northernmost, geographically isolated population. In a Bayesian analysis, microsatellite data suggested population structure at two levels: at K = 2 and at K = 3 in agreement to the geographical distribution of populations. This result was confirmed by the UPGMA dendrogram based on microsatellite data (bootstrap support > 95 %). Non-hierarchical AMOVA revealed high variation among populations from different A POSTERIORI defined geographical groups. The genetic distance between sample locations increased with geographical distance for microsatellites ( R = 0.62; P = 0.003) and AFLPs ( R = 0.32; P = 0.09). This pattern of population differentiation may be correlated with population history such as geographical isolation and postglacial colonization of highlands. Implications of the population genetic structure for the conservation of genetic resources are discussed. 相似文献
60.
模拟土壤温度升高对湿草甸小叶章生长及生理特性的影响 总被引:3,自引:0,他引:3
采用改进的电缆加热升温方法,研究了土壤温度升高1 ℃~3 ℃对湿草甸小叶章生长及生理特性的影响.结果表明:土壤温度升高明显促进了小叶章植株的生长淹水处理条件下各指标的增长程度依次为:根系总吸收面积(60%)>叶面积(37.32%)>分蘖数(25.81%)>根系体积(24.67%)>株高(18.2%);非淹水处理条件下为:根系总吸收面积(37.47%)>根系体积(36.26%)>叶面积(32.9%)>分蘖数(32.77%)>株高(12.09%).淹水处理条件下小叶章各生理指标对温度升高的响应较为显著,升温淹水处理下小叶章的总叶绿素含量、根部可溶性蛋白含量均呈增加趋势(9.8%和23.88%),而叶片可溶性蛋白和可溶性糖及根部可溶性糖含量显著下降(24.67%、22.92%和35.23%).说明土温升高1 ℃~3 ℃能够显著促进湿草甸小叶章的生长,且其生理特性对土温升高的响应程度因水分条件而异. 相似文献