[Objective] This study aimed to provide reference and reduce the workload for screening standard DNA barcoding genes of plants. [Method] Three DNA barcoding genes ITS, ITS2 and rbcL were amplified from seven Xanthium ...[Objective] This study aimed to provide reference and reduce the workload for screening standard DNA barcoding genes of plants. [Method] Three DNA barcoding genes ITS, ITS2 and rbcL were amplified from seven Xanthium species under the same PCR condition： PCR amplification was started with initial denaturation at 95 ℃ for 4 min, followed by 35 cycles of denaturation at 94 ℃ for 30 s, annealing at 52 ℃ for 45 s, and extension at 72 ℃ for 45 s; the amplification was completed by holding the reaction mixture at 72 ℃ for 10 min to allow complete extension of PCR, and the PCR products were stored at 4 ℃. [Result] Three DNA barcoding genes ITS, ITS2 and rbcL were all amplified successfully. [Conclusion] This study indicates that PCR amplification conditions for DNA barcoding genes ITS,ITS2 and rbcL in plants may be consistent.展开更多
[Objective] The study was aimed to provide theoretical foundation for developing a new fungicide with high activity,low toxicity and low residua.[Method] Based on the plant growth rate and inhibition zone methods,the ...[Objective] The study was aimed to provide theoretical foundation for developing a new fungicide with high activity,low toxicity and low residua.[Method] Based on the plant growth rate and inhibition zone methods,the antifungal activity of extracts of every organ of Xanthium sibiricum,the fermentation liquid of endophytic fungi MC4-23,and the extract of mycelium were tested with six kinds of pathogenic fungi and three kinds of pathogenic bacteria respectively.[Result] The extract of every organ of Xanthium sibiricum,the fermentation liquid of endophyic fungi MC4-23,and the extract of mycelium all had antifungal activities.The acetone extracts of Xanthium sibiricum had stronger antifungal activities than the ethanol extracts of Xanthium sibiricum.The extracts of leaf have the strongest antifungal activities against fungi and bacteria.The inhibition rates of the six pathogenic fungi were all above 47.8%,and the inhibition diameters of the three pathogenic bacteria were all above 0.5 centimeter.The fermentation liquid of endophytic fungi also had strong activities against the fungi and bacteria.The inhibition rates of the six pathogenic fungi were all above 68.1%.The extracts of root of Xanthium sibiricum and the mycelium of endophytic fungi were all had antifungal activities.[Conclusion] Xanthium sibiricum and endophyic fungi MC4-23 had great value of development and utilization.展开更多
Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish, implying that this invasive plant could release biologically active volatile organic compounds （VOCs） into the...Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish, implying that this invasive plant could release biologically active volatile organic compounds （VOCs） into the environment to affect other plants＇ growth. This phenomenon was further studied by evaluating the phytotoxic effects of X. italicum essential oil against two dicot plants, amaranth （Amaranthus mangostanus L.） and lettuce （Lectuca sativa L.）, and two monocot plants, wheat （Triticum aestivum Linn） and ryegrass （Lolium multiforum）, and analyzing the chemical composition of the oil. Among the 4 test species, amaranth was the most sensitive plant, 0.5μl/mL essential oil application resulted in a 50% reduction on root elongation, and 2.5 μl/mL essential oil almost completely inhibited its seedling growth. Wheat was the least sensitive species, whose root growth was reduced to 36% of control by 5 μl/mL essential oil. The essential oil exerted moderate inhibitory effect on both lettuce and ryegrass. Compared to a commercial herbicide-Harness, X. italicum oil exhibited stronger phytotoxicity on amaranth, lettuce and wheat, but weaker activity on ryegrass. The chemical composition of the essential oil isolated by hydrodistillation from the aerial parts of X. italicum Moretti was analyzed by GC/MS. Thirty two compounds were identified, representing 94.89% of total oil, which was found to be rich in monoterpene hydrocarbons （60.71%）. The main constituents of the oil were limonene （51.61%）, germacrene B （6.98%）, 6-cadinol （5.94%）, β-pinene （5.23%）, α-caryophyllene （5.1%） and bornyl acetate （3.15%）. Bioassay revealed the dominant constituent-limonene, was unlikely the responsible phytotoxic compound due to its low biological activity; rather, there might be other oil constituent（s） that either act alone, or work together, and possibly assisted by synergistic effect, to display the phytotoxic activity. Our results suggested that X. italicum might produce allelopathic VOCs to facilitate its invasion success. This is the first report on the phytotoxic activity and the chemical composition of the essential oil of X. itaficum Moretti from China.展开更多
Weed control is one of the major constraint factors in crop production around the world. Field experiments were conducted during 2008-2009 under intercropping systems involving alfalfa （Medicago sativa L.）, sweet po...Weed control is one of the major constraint factors in crop production around the world. Field experiments were conducted during 2008-2009 under intercropping systems involving alfalfa （Medicago sativa L.）, sweet potato （lpomoea batatas [L.] Lain.）, peanut （Arachis hypogaea L.）, and sunflower （Helianthus annuus L.） in maize （Zea mays L.） without any weeds control methods taken. The results demonstrate that maizellsunflower is most effective on weed suppression and that it also has a more competitively inhibitory effect on Xanthium compared with the other patterns by evaluating the Xanthium density and dry weight under different intercropping systems with maize. Maizellpeanut, maizellalfalfa and maizel]sweet potato intercrops have no apparent inhibitory effect on weeds. To further investigate the effect of maize]lsunflower on weed control, indoor pot experiments were conducted by determining the effect of extractions on germination rate （GR）, root vigor, MDA （malondialdehyde）, SOD （superoxide dismutase） and POD （peroxidase） content of Xanthium. The results better prove that maizellsunflower extractions have more significant inhibitory effect on GR and young root vigor of Xanthium than maize monocrop extractions.展开更多
[ Objective ] Xanthium plants （non-Chinese species） are quarantine pests in China. This study aimed to distinguish and identify seven Xanthium spe- cies using ITS2 sequence as DNA barcode. [Method] ITS2 gene was amp...[ Objective ] Xanthium plants （non-Chinese species） are quarantine pests in China. This study aimed to distinguish and identify seven Xanthium spe- cies using ITS2 sequence as DNA barcode. [Method] ITS2 gene was amplified using universal primers to obtain ITS2 sequences of seven Xanthium species, which were then sequenced. ITS2 sequences of seven Xanthium species were compared and analyzed by MEGA 5.1 software, and the phylogenetic tree was constructed. [ Result] A total of 242 variable sites were found in 1TS2 sequences of Xanthium species, including 12 singleton variable sites. [ Conclusion] Xanthium species can be distinguished and identified based on ITS2 sequences.展开更多
The fuel properties of coastal plant Xanthium sibiricum were investigated in thermogravimetrics.The distributed activation energy model was employed in the kinetic analysis and a simplified mathematical model that can...The fuel properties of coastal plant Xanthium sibiricum were investigated in thermogravimetrics.The distributed activation energy model was employed in the kinetic analysis and a simplified mathematical model that can predict the thermogravimetry curves was proposed.The results show that the initial decomposition temperature tends to increase with the heating rate.The distributed E values ranged from 169.08 to 177.43 kJ/mol,and the frequency factor values ranged from 6.59× 10~8 to 1.22×10^(12)/s at different conversion rates.Furthermore,the prediction made with the simplified mathematical model perfectly matched the experimental data,and the model was found to be simple and accurate for the prediction of devolatilization curves.展开更多
8,12-sesquiterpene lactones(STLs)are an important class of natural products with unique pharmaceutical activities.For years the pathway leading to 8,12-STLs remains an enigma.Xanthium strumarium accumulates abundant 8...8,12-sesquiterpene lactones(STLs)are an important class of natural products with unique pharmaceutical activities.For years the pathway leading to 8,12-STLs remains an enigma.Xanthium strumarium accumulates abundant 8,12-STLs,and xanthatin is a characteristic 8,12-STL in it.Xanthatin has been previously postulated to be derived from germacrene A,but the steps from germacrene A to xanthatin are unknown.As part of an effort to understand the xanthatin biosynthetic pathway.This study reports the characterization of a unique germacrene A oxidase(XsGAO)from X.strumarium.Unlike a classical GAO enzyme,which is known to catalyze a three-step oxidation of germarene A to yield germacrene A acid(GAA),surprisingly,XsGAO catalyzed only one-step conversion of germacrene A to germacrene A alcohol.We discussed that GAO may be pressured to acquire a novel activity during the evolutionary path for the biosynthesis of 8,12-STLs.展开更多
Xanthium strumarium(X.strumarium)is a traditional Chinese medicine with a long history.In recent years,with the development of modern pharmacology and chemical analysis technology,research on X.strumarium has been dee...Xanthium strumarium(X.strumarium)is a traditional Chinese medicine with a long history.In recent years,with the development of modern pharmacology and chemical analysis technology,research on X.strumarium has been deepend.This paper aims to systematically summarize the chemical compositions and pharmacological effects of X.strumarium,in order to provide theoretical basis and reference for further exploration in its clinical application and drug development.展开更多
Objective: To assess the impacts, mode of entry, trends, status, distribution and management practices of Xanthium strumarium (X. strumarium) in Borena Zone of Oromia Region. Methods: Four study districts and eight ke...Objective: To assess the impacts, mode of entry, trends, status, distribution and management practices of Xanthium strumarium (X. strumarium) in Borena Zone of Oromia Region. Methods: Four study districts and eight kebeles (peasant associations) were purposively selected based on distribution level and data from agricultural offices. Then, randomly, eight key informants were selected from each kebele. Data were collected using semi-structured interview and analyzed using SPSS version 21. Results: All respondents (100%) acknowledged that X. strumarium highly invaded the study area and its spread was increasing both in time and space. According to respondents, X. strumarium was introduced to the area mainly along with improved seed varieties, food aid, flood, animals and vehicles, and easily dispersed by clinging to animal hides and human clothing. In the past time, X. strumarium caused high level of damage on native biodiversity and thus respondents worried that this might continue in the future. Similarly, respondents (98.4%) stated that X. strumarium was out of control in the study area and they recommended further investigation by concerned body to control the spread. Conclusions: In conclusion, X. strumarium is spreading rapidly in the study area by threatening native biodiversity and adversely affecting agroeconomy of the farmers and the country. Therefore, it needs the effort of all concerned bodies to control the impacts.展开更多
Objective:To evaluate immature mosquitocidal properties of Xanthium strumarium plant extracts against Culex mosquitoes at Entomology Laboratory,Maraki Campus,University of Gondar.Methods:The immature mosquitocidal act...Objective:To evaluate immature mosquitocidal properties of Xanthium strumarium plant extracts against Culex mosquitoes at Entomology Laboratory,Maraki Campus,University of Gondar.Methods:The immature mosquitocidal activity of plant extracts was tested by following World Health Organization recommended protocol.Acetone,methanol and water extracts were prepared at 50,100,150,200 and 250 mg/L concentrations and tested against third and fourth instar larvae and pupae of Culex mosquitoes.The mortality rate of immature mosquitoes was recorded after 24,48 and 72 h exposure period continuously.Results:Third instar larvae after 24 h exposure period,maximum mortality of 77.80%was recorded at 250 mg/L concentration of acetone extract.After 48 h and 72 h exposure period,maximum mortality of 88.90%was recorded in acetone extract in all the tested concentration.The maximum mortality of fourth instar larvae was 88.90%in acetone extract at 200 and 250 mg/L concentrations.Pupal mortality was also greater in acetone extract.The percentage of mortality in all the stage of mosquitoes was higher in acetone extract followed by methanol and water extract.Conclusions:The percentage of mortality is associated with concentration of the extracts tested and exposure period.This laboratory study confirmed immature mosquitocidal activity of Xanthium strumarium leaf extracts against Culex mosquitoes.The aqueous leaf extract can be used by applying on small man-made breeding places to prevent adult emergence.展开更多
基金Supported by Science and Technology Project of Jiangsu Entry-Exit Inspection and Quarantine Bureau(2012KJ54)~~
文摘[Objective] This study aimed to provide reference and reduce the workload for screening standard DNA barcoding genes of plants. [Method] Three DNA barcoding genes ITS, ITS2 and rbcL were amplified from seven Xanthium species under the same PCR condition： PCR amplification was started with initial denaturation at 95 ℃ for 4 min, followed by 35 cycles of denaturation at 94 ℃ for 30 s, annealing at 52 ℃ for 45 s, and extension at 72 ℃ for 45 s; the amplification was completed by holding the reaction mixture at 72 ℃ for 10 min to allow complete extension of PCR, and the PCR products were stored at 4 ℃. [Result] Three DNA barcoding genes ITS, ITS2 and rbcL were all amplified successfully. [Conclusion] This study indicates that PCR amplification conditions for DNA barcoding genes ITS,ITS2 and rbcL in plants may be consistent.
基金Supported by Platform Project of the Ministry of Science and Technology of China for Microorganism Resources(2005DKA2120721)~~
文摘[Objective] The study was aimed to provide theoretical foundation for developing a new fungicide with high activity,low toxicity and low residua.[Method] Based on the plant growth rate and inhibition zone methods,the antifungal activity of extracts of every organ of Xanthium sibiricum,the fermentation liquid of endophytic fungi MC4-23,and the extract of mycelium were tested with six kinds of pathogenic fungi and three kinds of pathogenic bacteria respectively.[Result] The extract of every organ of Xanthium sibiricum,the fermentation liquid of endophyic fungi MC4-23,and the extract of mycelium all had antifungal activities.The acetone extracts of Xanthium sibiricum had stronger antifungal activities than the ethanol extracts of Xanthium sibiricum.The extracts of leaf have the strongest antifungal activities against fungi and bacteria.The inhibition rates of the six pathogenic fungi were all above 47.8%,and the inhibition diameters of the three pathogenic bacteria were all above 0.5 centimeter.The fermentation liquid of endophytic fungi also had strong activities against the fungi and bacteria.The inhibition rates of the six pathogenic fungi were all above 68.1%.The extracts of root of Xanthium sibiricum and the mycelium of endophytic fungi were all had antifungal activities.[Conclusion] Xanthium sibiricum and endophyic fungi MC4-23 had great value of development and utilization.
基金financially supported by the International Science and Technology Cooperation Program of China (2010 DFA 92720-06)the One Hundred Person Project of the Chinese Academy of Sciences granted to Chi ZHANGthe West Light Foundation of the Chinese Academy of Sciences granted to Hua SHAO (LHXZ201202)
文摘Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish, implying that this invasive plant could release biologically active volatile organic compounds （VOCs） into the environment to affect other plants＇ growth. This phenomenon was further studied by evaluating the phytotoxic effects of X. italicum essential oil against two dicot plants, amaranth （Amaranthus mangostanus L.） and lettuce （Lectuca sativa L.）, and two monocot plants, wheat （Triticum aestivum Linn） and ryegrass （Lolium multiforum）, and analyzing the chemical composition of the oil. Among the 4 test species, amaranth was the most sensitive plant, 0.5μl/mL essential oil application resulted in a 50% reduction on root elongation, and 2.5 μl/mL essential oil almost completely inhibited its seedling growth. Wheat was the least sensitive species, whose root growth was reduced to 36% of control by 5 μl/mL essential oil. The essential oil exerted moderate inhibitory effect on both lettuce and ryegrass. Compared to a commercial herbicide-Harness, X. italicum oil exhibited stronger phytotoxicity on amaranth, lettuce and wheat, but weaker activity on ryegrass. The chemical composition of the essential oil isolated by hydrodistillation from the aerial parts of X. italicum Moretti was analyzed by GC/MS. Thirty two compounds were identified, representing 94.89% of total oil, which was found to be rich in monoterpene hydrocarbons （60.71%）. The main constituents of the oil were limonene （51.61%）, germacrene B （6.98%）, 6-cadinol （5.94%）, β-pinene （5.23%）, α-caryophyllene （5.1%） and bornyl acetate （3.15%）. Bioassay revealed the dominant constituent-limonene, was unlikely the responsible phytotoxic compound due to its low biological activity; rather, there might be other oil constituent（s） that either act alone, or work together, and possibly assisted by synergistic effect, to display the phytotoxic activity. Our results suggested that X. italicum might produce allelopathic VOCs to facilitate its invasion success. This is the first report on the phytotoxic activity and the chemical composition of the essential oil of X. itaficum Moretti from China.
基金supported by the National Key Technologies R&D Program of China during the 11th Five-Year Planperiod (2007BAD89B01)
文摘Weed control is one of the major constraint factors in crop production around the world. Field experiments were conducted during 2008-2009 under intercropping systems involving alfalfa （Medicago sativa L.）, sweet potato （lpomoea batatas [L.] Lain.）, peanut （Arachis hypogaea L.）, and sunflower （Helianthus annuus L.） in maize （Zea mays L.） without any weeds control methods taken. The results demonstrate that maizellsunflower is most effective on weed suppression and that it also has a more competitively inhibitory effect on Xanthium compared with the other patterns by evaluating the Xanthium density and dry weight under different intercropping systems with maize. Maizellpeanut, maizellalfalfa and maizel]sweet potato intercrops have no apparent inhibitory effect on weeds. To further investigate the effect of maize]lsunflower on weed control, indoor pot experiments were conducted by determining the effect of extractions on germination rate （GR）, root vigor, MDA （malondialdehyde）, SOD （superoxide dismutase） and POD （peroxidase） content of Xanthium. The results better prove that maizellsunflower extractions have more significant inhibitory effect on GR and young root vigor of Xanthium than maize monocrop extractions.
基金Supported by Science and Technology Project of Jiangsu Entry-Exit Inspection and Quarantine Bureau(2012KJ54)
文摘[ Objective ] Xanthium plants （non-Chinese species） are quarantine pests in China. This study aimed to distinguish and identify seven Xanthium spe- cies using ITS2 sequence as DNA barcode. [Method] ITS2 gene was amplified using universal primers to obtain ITS2 sequences of seven Xanthium species, which were then sequenced. ITS2 sequences of seven Xanthium species were compared and analyzed by MEGA 5.1 software, and the phylogenetic tree was constructed. [ Result] A total of 242 variable sites were found in 1TS2 sequences of Xanthium species, including 12 singleton variable sites. [ Conclusion] Xanthium species can be distinguished and identified based on ITS2 sequences.
基金Supported by the National Key Technology R&D Program of China(Nos.2011BAD13B07,2013BAB01B00)
文摘The fuel properties of coastal plant Xanthium sibiricum were investigated in thermogravimetrics.The distributed activation energy model was employed in the kinetic analysis and a simplified mathematical model that can predict the thermogravimetry curves was proposed.The results show that the initial decomposition temperature tends to increase with the heating rate.The distributed E values ranged from 169.08 to 177.43 kJ/mol,and the frequency factor values ranged from 6.59× 10~8 to 1.22×10^(12)/s at different conversion rates.Furthermore,the prediction made with the simplified mathematical model perfectly matched the experimental data,and the model was found to be simple and accurate for the prediction of devolatilization curves.
基金This work was supported by a grant from the National Natural Science Foundation of China(31370339).
文摘8,12-sesquiterpene lactones(STLs)are an important class of natural products with unique pharmaceutical activities.For years the pathway leading to 8,12-STLs remains an enigma.Xanthium strumarium accumulates abundant 8,12-STLs,and xanthatin is a characteristic 8,12-STL in it.Xanthatin has been previously postulated to be derived from germacrene A,but the steps from germacrene A to xanthatin are unknown.As part of an effort to understand the xanthatin biosynthetic pathway.This study reports the characterization of a unique germacrene A oxidase(XsGAO)from X.strumarium.Unlike a classical GAO enzyme,which is known to catalyze a three-step oxidation of germarene A to yield germacrene A acid(GAA),surprisingly,XsGAO catalyzed only one-step conversion of germacrene A to germacrene A alcohol.We discussed that GAO may be pressured to acquire a novel activity during the evolutionary path for the biosynthesis of 8,12-STLs.
基金supported by National Nature Science Foundation of China(81973284)Scientific Research Foundation of the Education Department of Liaoning Province(LJKZ0944).
文摘Xanthium strumarium(X.strumarium)is a traditional Chinese medicine with a long history.In recent years,with the development of modern pharmacology and chemical analysis technology,research on X.strumarium has been deepend.This paper aims to systematically summarize the chemical compositions and pharmacological effects of X.strumarium,in order to provide theoretical basis and reference for further exploration in its clinical application and drug development.
文摘Objective: To assess the impacts, mode of entry, trends, status, distribution and management practices of Xanthium strumarium (X. strumarium) in Borena Zone of Oromia Region. Methods: Four study districts and eight kebeles (peasant associations) were purposively selected based on distribution level and data from agricultural offices. Then, randomly, eight key informants were selected from each kebele. Data were collected using semi-structured interview and analyzed using SPSS version 21. Results: All respondents (100%) acknowledged that X. strumarium highly invaded the study area and its spread was increasing both in time and space. According to respondents, X. strumarium was introduced to the area mainly along with improved seed varieties, food aid, flood, animals and vehicles, and easily dispersed by clinging to animal hides and human clothing. In the past time, X. strumarium caused high level of damage on native biodiversity and thus respondents worried that this might continue in the future. Similarly, respondents (98.4%) stated that X. strumarium was out of control in the study area and they recommended further investigation by concerned body to control the spread. Conclusions: In conclusion, X. strumarium is spreading rapidly in the study area by threatening native biodiversity and adversely affecting agroeconomy of the farmers and the country. Therefore, it needs the effort of all concerned bodies to control the impacts.
基金Supported by University of Gondar(UoG/Budget/no 6215/2015).
文摘Objective:To evaluate immature mosquitocidal properties of Xanthium strumarium plant extracts against Culex mosquitoes at Entomology Laboratory,Maraki Campus,University of Gondar.Methods:The immature mosquitocidal activity of plant extracts was tested by following World Health Organization recommended protocol.Acetone,methanol and water extracts were prepared at 50,100,150,200 and 250 mg/L concentrations and tested against third and fourth instar larvae and pupae of Culex mosquitoes.The mortality rate of immature mosquitoes was recorded after 24,48 and 72 h exposure period continuously.Results:Third instar larvae after 24 h exposure period,maximum mortality of 77.80%was recorded at 250 mg/L concentration of acetone extract.After 48 h and 72 h exposure period,maximum mortality of 88.90%was recorded in acetone extract in all the tested concentration.The maximum mortality of fourth instar larvae was 88.90%in acetone extract at 200 and 250 mg/L concentrations.Pupal mortality was also greater in acetone extract.The percentage of mortality in all the stage of mosquitoes was higher in acetone extract followed by methanol and water extract.Conclusions:The percentage of mortality is associated with concentration of the extracts tested and exposure period.This laboratory study confirmed immature mosquitocidal activity of Xanthium strumarium leaf extracts against Culex mosquitoes.The aqueous leaf extract can be used by applying on small man-made breeding places to prevent adult emergence.
