Plants of Baccharis （Asteraceae） genus are commonly known in Argentina as ＂carqueja＂. The antimicrobial activity and minimal inhibitory concentration of B. articulata, B. trimera and B. crispa aqueous and ethanoli...Plants of Baccharis （Asteraceae） genus are commonly known in Argentina as ＂carqueja＂. The antimicrobial activity and minimal inhibitory concentration of B. articulata, B. trimera and B. crispa aqueous and ethanolic extracts were evaluated by using the micro-well dilution method. Previously, the components of extracts were analyzed by spectroscopial means. Gram-positive bacteria were more sensitive to Baccharis species extracts than Gram-negative bacteria. Out of 3 plant species, B. trimera showed significant antibacterial activity and aqueous and ethanolic extracts were active against Staphylococcus aureus （MIC = 2,500 μg/mL and 1,250 μg/mL, respectively） and Listeria monocytogenes （MIC = 625 μg/mL and 625 μg/mL, respectively）. All ethanolic extracts inhibited the growth of the selected Gram-positive （MIC values ranged between 625 μg/mL and 1,250 μg/mL）. Therefore, all Gram-negative bacteria were resistant to the ethanolic and aqueous extracts tested. One flavone, genkawanin, was identified from the three ethanolic extracts as the responsible of antibacterial activity. Two terpenes, hawtriwaic acid and bacrispine, were identified from ethanolic extract of B. crispa and B. trimera as the responsibles of antibacterial activity. These preliminary studies corroborated the antimicrobial activity of the selected plants used in folklore medicine. Therefore, they could be potential sources of new antimicrobial agents used in treatment of infectious diseases.展开更多
This study aimed to investigate, for the first time, the plant growth, essential oil content and their chemical substances ofBaccharis trimera （Less.） DC., the first Brazilian variety of medicinal plant, in response...This study aimed to investigate, for the first time, the plant growth, essential oil content and their chemical substances ofBaccharis trimera （Less.） DC., the first Brazilian variety of medicinal plant, in response to five doses of organic fertilizer （0, 10, 20,30, 40 and 50 ton/ha） over two harvest moments-120 d and 242 d after transplanting （DAT）. The work was carried out fromFebruary to October 2011 at the experimental farm of the Sao Paulo State University ＂Julio de Mesquita Filho＂ （UNESP）, Brazil.The seedlings of B. trimera var. CPQBA-1 were respectively transplanted into experiment plots under six treatments： 0, 10, 20, 30,40 and 50 ton/ha of organic fertilizer. Each treatment had four replications and each plot consisted of 12 plants. Then they wereharvested at 120 DAT and 242 DAT, and the essential oil were extracted by hydrodistillation and analyzed by gas chromatograph.The results were subjected to analysis of variance and the means were analysed using Tukey＇s test （5%） followed by a regressionanalysis. The fertilizer dose significantly influenced the height of the plants in the second harvest, while the higher dose of organicfertilizer positively impacted the essential oil content in the first harvest. Also, the level of organic fertilizer was directly correlatedwith the production of dry matter during the regrowth. Twenty-seven substances were identified in the essential oil samples, and themajor components were： bicyclogermacrene, trans-caryophyllene, germacrene-D, spathulenol and caryophyllene oxide. Thesefindings suggest that to obtain higher yields of dry matter ofB. trimera, it should be harvested around 242 DAT and organic fertilizershould be applied approximately to 50 ton/ha. Furthermore, higher doses of organic fertilizer and harvest at 120 DAT is able toincrease the essential oil content.展开更多
Aims While a growing number of studies have demonstrated the impor-tance of intraspecific differences within plant species on associ-ated arthropod communities,little is known regarding the relative strength of these ...Aims While a growing number of studies have demonstrated the impor-tance of intraspecific differences within plant species on associ-ated arthropod communities,little is known regarding the relative strength of these effects compared to environmental factors.In this study,we examined whether intraspecific plant differences and nutrient fertilization interact to shape the arthropod community of a dominant coastal shrub,Baccharis pilularis(coyote bush).Methods We overlaid a fertilization treatment on a 12-year-old common garden experiment planted with erect and prostrate architectural morphs of Baccharis in california,USA.to collect the associated arthropod community,we vacuum sampled the crown of each Baccharis and identified individuals to species or morphospecies.Important Findings We found that arthropod richness and abundance were 2-to 3-fold greater on prostrate Baccharis than on erect morphs,but observed no main effects of fertilizer addition on the over-all arthropod communities.Predators responded as strongly as herbivores to plant morph,and both were unaffected by nutrient additions.Only the specialist stem galler,Gnorimoschema bac-charisella,showed an interactive response to plant morph and fertilization.Nitrogen,phosphorous and potassium addition had opposite effects on the two morphs,increasing stem gall abun-dance by 50%on prostrate morphs,but reducing galling by 20%on erect morphs.the architectural complexity of prostrate morphs could be the driving mechanism of differences in arthropod assemblages.Overall,our results demonstrate that communitylevel consequences of intraspecific differences in plants are strong,rather than being context dependent,and are generally maintained under different resource environments.the growing number of studies showing strong genotype than nutrient effects on associated arthropod communities suggests that this might be a generalized pattern.展开更多
文摘Plants of Baccharis （Asteraceae） genus are commonly known in Argentina as ＂carqueja＂. The antimicrobial activity and minimal inhibitory concentration of B. articulata, B. trimera and B. crispa aqueous and ethanolic extracts were evaluated by using the micro-well dilution method. Previously, the components of extracts were analyzed by spectroscopial means. Gram-positive bacteria were more sensitive to Baccharis species extracts than Gram-negative bacteria. Out of 3 plant species, B. trimera showed significant antibacterial activity and aqueous and ethanolic extracts were active against Staphylococcus aureus （MIC = 2,500 μg/mL and 1,250 μg/mL, respectively） and Listeria monocytogenes （MIC = 625 μg/mL and 625 μg/mL, respectively）. All ethanolic extracts inhibited the growth of the selected Gram-positive （MIC values ranged between 625 μg/mL and 1,250 μg/mL）. Therefore, all Gram-negative bacteria were resistant to the ethanolic and aqueous extracts tested. One flavone, genkawanin, was identified from the three ethanolic extracts as the responsible of antibacterial activity. Two terpenes, hawtriwaic acid and bacrispine, were identified from ethanolic extract of B. crispa and B. trimera as the responsibles of antibacterial activity. These preliminary studies corroborated the antimicrobial activity of the selected plants used in folklore medicine. Therefore, they could be potential sources of new antimicrobial agents used in treatment of infectious diseases.
文摘This study aimed to investigate, for the first time, the plant growth, essential oil content and their chemical substances ofBaccharis trimera （Less.） DC., the first Brazilian variety of medicinal plant, in response to five doses of organic fertilizer （0, 10, 20,30, 40 and 50 ton/ha） over two harvest moments-120 d and 242 d after transplanting （DAT）. The work was carried out fromFebruary to October 2011 at the experimental farm of the Sao Paulo State University ＂Julio de Mesquita Filho＂ （UNESP）, Brazil.The seedlings of B. trimera var. CPQBA-1 were respectively transplanted into experiment plots under six treatments： 0, 10, 20, 30,40 and 50 ton/ha of organic fertilizer. Each treatment had four replications and each plot consisted of 12 plants. Then they wereharvested at 120 DAT and 242 DAT, and the essential oil were extracted by hydrodistillation and analyzed by gas chromatograph.The results were subjected to analysis of variance and the means were analysed using Tukey＇s test （5%） followed by a regressionanalysis. The fertilizer dose significantly influenced the height of the plants in the second harvest, while the higher dose of organicfertilizer positively impacted the essential oil content in the first harvest. Also, the level of organic fertilizer was directly correlatedwith the production of dry matter during the regrowth. Twenty-seven substances were identified in the essential oil samples, and themajor components were： bicyclogermacrene, trans-caryophyllene, germacrene-D, spathulenol and caryophyllene oxide. Thesefindings suggest that to obtain higher yields of dry matter ofB. trimera, it should be harvested around 242 DAT and organic fertilizershould be applied approximately to 50 ton/ha. Furthermore, higher doses of organic fertilizer and harvest at 120 DAT is able toincrease the essential oil content.
基金EEB summer grants from the Department of Ecology and Evolutionary Biology,University of Tennessee(to M.N.B.-G.and M.A.R.-C.)the Miller Institute for Basic Research in Science(to G.M.C.).
文摘Aims While a growing number of studies have demonstrated the impor-tance of intraspecific differences within plant species on associ-ated arthropod communities,little is known regarding the relative strength of these effects compared to environmental factors.In this study,we examined whether intraspecific plant differences and nutrient fertilization interact to shape the arthropod community of a dominant coastal shrub,Baccharis pilularis(coyote bush).Methods We overlaid a fertilization treatment on a 12-year-old common garden experiment planted with erect and prostrate architectural morphs of Baccharis in california,USA.to collect the associated arthropod community,we vacuum sampled the crown of each Baccharis and identified individuals to species or morphospecies.Important Findings We found that arthropod richness and abundance were 2-to 3-fold greater on prostrate Baccharis than on erect morphs,but observed no main effects of fertilizer addition on the over-all arthropod communities.Predators responded as strongly as herbivores to plant morph,and both were unaffected by nutrient additions.Only the specialist stem galler,Gnorimoschema bac-charisella,showed an interactive response to plant morph and fertilization.Nitrogen,phosphorous and potassium addition had opposite effects on the two morphs,increasing stem gall abun-dance by 50%on prostrate morphs,but reducing galling by 20%on erect morphs.the architectural complexity of prostrate morphs could be the driving mechanism of differences in arthropod assemblages.Overall,our results demonstrate that communitylevel consequences of intraspecific differences in plants are strong,rather than being context dependent,and are generally maintained under different resource environments.the growing number of studies showing strong genotype than nutrient effects on associated arthropod communities suggests that this might be a generalized pattern.
