Specimens of Cymodocea(Viridiplantae,Magnoliophyta)collected on the Tunisian coasts showed a particular morphological and anatomical difference with the classical descriptions of Cymodocea nodosa(Ucria)Asch.the only s...Specimens of Cymodocea(Viridiplantae,Magnoliophyta)collected on the Tunisian coasts showed a particular morphological and anatomical difference with the classical descriptions of Cymodocea nodosa(Ucria)Asch.the only species of this genus reported in the Mediterranean Sea.In order to precise the taxonomic identity of the new specimens we aimed in this work(i)to verify the identity of the new forms,(ii)to evaluate the genetic diversity of the population,(iii)to test the validity of the existing identification keys of the Tunisian Cymodocea populations.Four stations located in two regions of the Tunisian coasts were sampled.Leaf morphological and anatomical characters used in taxonomic identification were measured(e.g.,number of cross veins,shape of the apex).The genetic study was performed using three most common chloroplast markers for plant characterization(DNA barcodes rbcL,matK and trnHpsbA).The morphological study revealed the presence of three C.nodosa morphotypes,described here for the first time,while the molecular characterization did not allow the discrimination of these morphological types.In regard to these results,it would be wise to review the classical identification keys of the Cymodocea genus.展开更多
Objective:To monitor the distribution of Cymodocea nodosa(Ucria)Ascherson in Las Canteras Beach(Las Palmas de Gran Canaria,Spain),comparing the status in 2005 with the distribution observed in 1985 and 1995.Methods:Fi...Objective:To monitor the distribution of Cymodocea nodosa(Ucria)Ascherson in Las Canteras Beach(Las Palmas de Gran Canaria,Spain),comparing the status in 2005 with the distribution observed in 1985 and 1995.Methods:Field observations by selfcontained underwater breathing apparatus diving records and cartographic report.Results:The seagrass meadow originally distributed between the beach and a bar of volcanic rocks,which sheltered it from the strong north-east winds and swells.Since 1985 a gradual reduction of its extent has been observed and more than 80%of the original canopy disappeared in twenty years time,mostly due to the anthropogenic impact and modification of the sedimentary dynamics of the beach.Conclusions:The degradation of this seagrass meadow determinates the loss of the only meadow in the north of the island of Gran Canaria and the absence of a management plan for its conservation.展开更多
Objective:To evaluate the antibacterial activity of Halophila stipulacea(H.stipulacea), Cymodocea serrulata(C.serrulata) and Halodule pinifolia(H.pinifolia) against seven human bacterial pathogens.Methods:The antibact...Objective:To evaluate the antibacterial activity of Halophila stipulacea(H.stipulacea), Cymodocea serrulata(C.serrulata) and Halodule pinifolia(H.pinifolia) against seven human bacterial pathogens.Methods:The antibacterial activities of the extracts on the various test organisms using disc diffusion method and Minimum Inhibitory Concentraction(MIC).Results: Methanol and chloroform extracts of all the three seagrasses were active against all the tested pathogens,whereas the hexane extract of seagrasses was not active against Staphylococcus aureus (S.aureus).Antibacterial activity of three seagrass screened,was in the order of H.pinifolia 】 H.stipulacea.】 C.serrulata.Conclusions:This antibacterial studies can further investigated on seagrasses for purification of bioactive substance and its possible utility in disease control.展开更多
Objective:To identify the larvieidal activity of the seagrass extracts.Methods:Seagrass extracts,Syringodium isoelifolium(.S.isoetifolium),Cymodocea serrulata and Hulophila beccarii,were dissolved in DMSO to prepare a...Objective:To identify the larvieidal activity of the seagrass extracts.Methods:Seagrass extracts,Syringodium isoelifolium(.S.isoetifolium),Cymodocea serrulata and Hulophila beccarii,were dissolved in DMSO to prepare a graded series of concentration.Batches of 25 early 4th instars larvae of Aedes aegypti(Ae.aegypti) were transferred to 250 ml.enamel bowl containing199 mL of distilled water and 1 mL of plant extracts(0.01 mg- 0.1 mg).After 24 h the mortality rate was identified with the formulae[(%of lest mortality-%of control mortality)/(100-%of control morlality)]× 100.Each experiment was conducted with three replicates and a concurrent control group.A control group consisted of 1 mL of DMSO and 199 mL of distilled water only.Results:The root extract of S.isoelifolium showed maximum larvicidal activity with minimum concentration of extract of LC_(50)= 0.0604 ± 0.0040)μg/mL with lower confidence limit(LCL)-upper confidence limit(UCL) =(0.051-0.071) and LC_(90)=0.0972 μg/mL followed by leaf extract of S.isoelifolium showed LC_(50)=(0.062 ± 0.005)μ'g/mL.The regression equation of pool and leaf extract of S.isoelifolium for4th instar larvae were Y =4.909- 1.32x(R^2= 0.909) and Y= 2.066+ 1.2x(R^2 =0.897) respectively.The results of the preliminary photochemical constituents shows the presence of saponin,steroids,terpenoid,phenols,protein and sugars.Conclusions:from the present study the ethanolic extracts of seagrass of S.isoelifolium possesses lead compound for development of larvieidal activity.展开更多
文摘Specimens of Cymodocea(Viridiplantae,Magnoliophyta)collected on the Tunisian coasts showed a particular morphological and anatomical difference with the classical descriptions of Cymodocea nodosa(Ucria)Asch.the only species of this genus reported in the Mediterranean Sea.In order to precise the taxonomic identity of the new specimens we aimed in this work(i)to verify the identity of the new forms,(ii)to evaluate the genetic diversity of the population,(iii)to test the validity of the existing identification keys of the Tunisian Cymodocea populations.Four stations located in two regions of the Tunisian coasts were sampled.Leaf morphological and anatomical characters used in taxonomic identification were measured(e.g.,number of cross veins,shape of the apex).The genetic study was performed using three most common chloroplast markers for plant characterization(DNA barcodes rbcL,matK and trnHpsbA).The morphological study revealed the presence of three C.nodosa morphotypes,described here for the first time,while the molecular characterization did not allow the discrimination of these morphological types.In regard to these results,it would be wise to review the classical identification keys of the Cymodocea genus.
基金Supported by the Obra Social de La Caja Insular de Ahorros de Canarias(2004-2005).
文摘Objective:To monitor the distribution of Cymodocea nodosa(Ucria)Ascherson in Las Canteras Beach(Las Palmas de Gran Canaria,Spain),comparing the status in 2005 with the distribution observed in 1985 and 1995.Methods:Field observations by selfcontained underwater breathing apparatus diving records and cartographic report.Results:The seagrass meadow originally distributed between the beach and a bar of volcanic rocks,which sheltered it from the strong north-east winds and swells.Since 1985 a gradual reduction of its extent has been observed and more than 80%of the original canopy disappeared in twenty years time,mostly due to the anthropogenic impact and modification of the sedimentary dynamics of the beach.Conclusions:The degradation of this seagrass meadow determinates the loss of the only meadow in the north of the island of Gran Canaria and the absence of a management plan for its conservation.
文摘Objective:To evaluate the antibacterial activity of Halophila stipulacea(H.stipulacea), Cymodocea serrulata(C.serrulata) and Halodule pinifolia(H.pinifolia) against seven human bacterial pathogens.Methods:The antibacterial activities of the extracts on the various test organisms using disc diffusion method and Minimum Inhibitory Concentraction(MIC).Results: Methanol and chloroform extracts of all the three seagrasses were active against all the tested pathogens,whereas the hexane extract of seagrasses was not active against Staphylococcus aureus (S.aureus).Antibacterial activity of three seagrass screened,was in the order of H.pinifolia 】 H.stipulacea.】 C.serrulata.Conclusions:This antibacterial studies can further investigated on seagrasses for purification of bioactive substance and its possible utility in disease control.
基金Supported by Ministry of Environment and Forest[Grant No.D.O.NO.3/2/2004 CS(M)-11.12.2006]
文摘Objective:To identify the larvieidal activity of the seagrass extracts.Methods:Seagrass extracts,Syringodium isoelifolium(.S.isoetifolium),Cymodocea serrulata and Hulophila beccarii,were dissolved in DMSO to prepare a graded series of concentration.Batches of 25 early 4th instars larvae of Aedes aegypti(Ae.aegypti) were transferred to 250 ml.enamel bowl containing199 mL of distilled water and 1 mL of plant extracts(0.01 mg- 0.1 mg).After 24 h the mortality rate was identified with the formulae[(%of lest mortality-%of control mortality)/(100-%of control morlality)]× 100.Each experiment was conducted with three replicates and a concurrent control group.A control group consisted of 1 mL of DMSO and 199 mL of distilled water only.Results:The root extract of S.isoelifolium showed maximum larvicidal activity with minimum concentration of extract of LC_(50)= 0.0604 ± 0.0040)μg/mL with lower confidence limit(LCL)-upper confidence limit(UCL) =(0.051-0.071) and LC_(90)=0.0972 μg/mL followed by leaf extract of S.isoelifolium showed LC_(50)=(0.062 ± 0.005)μ'g/mL.The regression equation of pool and leaf extract of S.isoelifolium for4th instar larvae were Y =4.909- 1.32x(R^2= 0.909) and Y= 2.066+ 1.2x(R^2 =0.897) respectively.The results of the preliminary photochemical constituents shows the presence of saponin,steroids,terpenoid,phenols,protein and sugars.Conclusions:from the present study the ethanolic extracts of seagrass of S.isoelifolium possesses lead compound for development of larvieidal activity.
