The Study On The Allelopathy Of Extracts Of The Root And The Rhizosphere Of Parsley On Fusarium Oxysporiumf. Sp.cucumeris

Allelopathy exists abroad in the nature, which has become one of most developing future technology for sustainable agriculture at 21st century, because it doesn't introduce chemical substances to the nature system that are decomposed difficultly, and it without remnant poison or environment pollute, and so on. Thus, allelopathy is a potential measure on the prevention of diseases to sustainable agriculture development. In the study, the allelopathy of the extracts of the root and the rhizosperic soil of parsley on Fusarium oxysporiumf.sp.cucumeris was studied by growth rate method .The results showed all had allelopathy on Fusarium oxysporiumf.sp.cucumeris that the extracts of the root of parsley from different solvent(water,ethanol, diethyl ether) in different degree .The aqueous extract of the root of parsley inhibited the growth of Fusarium oxysporiumf. sp.cucumeris at higher concentrations (from 100% to 10% ) , and the lower concentration of them promoted the mycelial growth ; the ethanol or diethyl ether extract of the root of parsley inhibited the growth of Fusarium oxysporiumf.sp.cucumeris within the range of experimental concentration; that the extract of ethanol inhibited the growth of Fusarium oxysporiumf.sp.cucumeris was superior to the other solvents , the inhibitory rate reached 42.31%. there was a tendency that inhibitory rate of different solvent extract of root agaist Fusarium oxysporiumf.sp.cucumeris dropped down with decreasing concentration and prolong time. the ethanol extract of the rhizosporic soil of parsley inhibited the growth of Fusarium oxysporiumf.sp.cucumeris significantly at higher concentrations(from RS100% to RS60% ), and the largest inhibitory rate was 94.3%. The higher concentration, the better allelopathic effect, which was more than that of corresponding extract of the nonrhizosphere, adding up to 49.02%; the lower concentration (RS40% and RS20%)of the ethanol extract of the rhizosperic soil of parsley promoted the mycelial growth lightly, but which was less than that of corresponding extract of the nonrhizosphere obviously. the rule of result about allelopathy of aqueous extract of the rhizosperic soil of parsley on Fusarium oxysporiumf. sp. cucumeris was similar with that of ethanol extract, but the inhibitory rate of aqueous extract aganst Fusarium oxysporiumf.sp.cucumeris were less than that of ethanol extract, and its highest inhibitory rate was 21.27%; however, diethyl ether extract of the rhizosperic soil of parsley increased the mycelial growth more or less, but all were less than that of corresponding extracts of the soil in same condition .the extract of the root or the rhizosperic soil of parsley all had allelopathy agaist Fusarium oxysporiumf. sp. cucumeris evidently, which related to the concentration of extract and acting time. In this study, ethanol was optimal as solvent, but diethyl ether was not appropriate to extract the rhizosperic soil of parsley.