A phytotoxin from Xanthomonas campestris pv. retroflexus was isolated using a chromatographer and HPLC, and the components were identified to be a mixture of minor molecular compounds including organic acids and cyclo...A phytotoxin from Xanthomonas campestris pv. retroflexus was isolated using a chromatographer and HPLC, and the components were identified to be a mixture of minor molecular compounds including organic acids and cyclo-（proline-phenylalanine）. The greenhouse cultivation test was used to determine the influence of the isolated fractions on the growth of target weed redroot pigweed （Amaranthus retroflexus L）. The experimental results demonstrated that the cyclo-（Pro-Phe） had the weed inhibit activity obviously on dicotyledonous weed and the mixture with six organic acids showed stronger bioactivity. Further, greenhouse and field test were processed, and the test showed that the use of the toxin appeared to have the potential to be developed further as a bioherbicide system to control weedy grasses.展开更多
The genus Phaeoacremonium is associated die-back of various woody hosts. In this study, Phaeoaeremonium specie was isolated from necrotic woody tissue of Platanus occidentalies L. （Platanus）. Morphological and cultu...The genus Phaeoacremonium is associated die-back of various woody hosts. In this study, Phaeoaeremonium specie was isolated from necrotic woody tissue of Platanus occidentalies L. （Platanus）. Morphological and cultural characteristics were used to identify the species, which known, and being described as Phaeoacremonium aleophillum. This is the first report on identifying Phaeoacremonium aleophillum from Platanus in Iraq, previously reports accommodate Cephalosporium acremonium from Platanus trees. This specie is able to produce toxic metabolites. Applications of P. aleophillum crude and cell-free filtrates induced severe chlorosis and necrosis on Platanus leaves after 24 hours of treatment with P. aleophillum culture filtrate. A novel phytotoxin was isolated from P. aleophillurn and culture filtrate was identified as galactouronic acid.展开更多
Nimbya alternantherae is a leaf spot fungus isolated from Alternanthera philoxeroides.It could produce phytotoxin to Alternanthera philoxeroides in several kinds of liquid media,especially in modified Fries.The filtra...Nimbya alternantherae is a leaf spot fungus isolated from Alternanthera philoxeroides.It could produce phytotoxin to Alternanthera philoxeroides in several kinds of liquid media,especially in modified Fries.The filtrate of the pathogen was chromatographed on a DM-130 colophony column eluting with methanol,and evaporation of the solvent gave a brown mush.The crude product was then extracted with ethyl acetate.The toxin could be purified as white needles by re-crystallizing from benzene and acetone（volume ratio is 1∶1） and silica gel chromatograph.The results of elemental analysis,MS,IR and NMR indicate that molecular weight of the toxin was 240,formula was C11H12O6,and its chemical name was 2-acetyl-3,4-dihydroxy-5-methoxyphenyl-acetic acid（Vulculic acid）.展开更多
基金Supported by the National Natural Science Fotmdation of China （No.30370939）, Natural Science Foundation of Zhejiang Province （No.300054） and Science Research Plan of Zhejiang Province （No.2004C22005）.
文摘A phytotoxin from Xanthomonas campestris pv. retroflexus was isolated using a chromatographer and HPLC, and the components were identified to be a mixture of minor molecular compounds including organic acids and cyclo-（proline-phenylalanine）. The greenhouse cultivation test was used to determine the influence of the isolated fractions on the growth of target weed redroot pigweed （Amaranthus retroflexus L）. The experimental results demonstrated that the cyclo-（Pro-Phe） had the weed inhibit activity obviously on dicotyledonous weed and the mixture with six organic acids showed stronger bioactivity. Further, greenhouse and field test were processed, and the test showed that the use of the toxin appeared to have the potential to be developed further as a bioherbicide system to control weedy grasses.
文摘The genus Phaeoacremonium is associated die-back of various woody hosts. In this study, Phaeoaeremonium specie was isolated from necrotic woody tissue of Platanus occidentalies L. （Platanus）. Morphological and cultural characteristics were used to identify the species, which known, and being described as Phaeoacremonium aleophillum. This is the first report on identifying Phaeoacremonium aleophillum from Platanus in Iraq, previously reports accommodate Cephalosporium acremonium from Platanus trees. This specie is able to produce toxic metabolites. Applications of P. aleophillum crude and cell-free filtrates induced severe chlorosis and necrosis on Platanus leaves after 24 hours of treatment with P. aleophillum culture filtrate. A novel phytotoxin was isolated from P. aleophillurn and culture filtrate was identified as galactouronic acid.
基金National 863 Project(2001AA246012)National Science Foundation of China(301 70619,30300024)+1 种基金Jiangsu Province Science Foundation(BK2001066)Key Technologies R&D Program for 10th Five-year Plans(2001BA611B-06-1-5)
文摘Nimbya alternantherae is a leaf spot fungus isolated from Alternanthera philoxeroides.It could produce phytotoxin to Alternanthera philoxeroides in several kinds of liquid media,especially in modified Fries.The filtrate of the pathogen was chromatographed on a DM-130 colophony column eluting with methanol,and evaporation of the solvent gave a brown mush.The crude product was then extracted with ethyl acetate.The toxin could be purified as white needles by re-crystallizing from benzene and acetone（volume ratio is 1∶1） and silica gel chromatograph.The results of elemental analysis,MS,IR and NMR indicate that molecular weight of the toxin was 240,formula was C11H12O6,and its chemical name was 2-acetyl-3,4-dihydroxy-5-methoxyphenyl-acetic acid（Vulculic acid）.
