| Wood is susceptible to fungal decay in use of process,resulting in waste of wood and the decrease of mechanical properties.Now,the water-borne wood preservatives could effectively improve the anti-fungi property of wood.However,if the treated woods with wood preservatives after the expiration of life were not harmless treatment,they would be harmful to the ecological environment.Therefore,the low toxic and efficient wood preservatives from the plant have been became a research focus recent years.Moreover,the wood has anisotropic properties,and leading to the lower uptake of wood preservative.Thus,the high-pressure treatment,etc.were usually used to improve the uptake of preservatives,and the anti-fungi ability of wood.So the uptake of wood preservatives would be improved with the effective changes in the permeability.Based on the knowledge that the burdock leaves contain a variety of antifungal active ingredients which could achieve a better antifungal property against wood fungi,and the Coriolus versicolor could change the permeability of wood.The antifungal substances in burdock leaves were extracted and mixed with the traditional preservatives to obtain a new wood preservative with lower toxicity and high efficiency in this paper.And the sapwood of Populus davidiana was bioincied by Coriolus versicolor to improve the permeability and antifungal property.The conclusions are of great significance,which provides a scientific and theoretical basis for the anti-fungi property of fast-growing forest.The main contents and conclusions of this paper are listed as follows:(1)The extraction of burdock leaves was carried out by pre-test,single factor and Response Surface Method,and the composition was analyzed by liquid chromatography.The results showed that the average extraction rate was 44.86%.And the main components of the extract were organic acids,flavonoids,alcohols and other antibacterial active substances,indicated that this extract method could effectively obtain the active ingredient in burdock leaves.(2)The effects of extracts from burdock leaves on C.versicolor,Gloceophyllum trabeum and enzyme secretion were analyzed.The results showed that the extract had better antifungal property against the two kinds of wood decay fungi.And the minimum inhibitory concentration was 1.88%,2.31%,the minimum bactericidal concentrations against C.versicolor and G.trabeum were about 2.2% and 3.0%,respectively.The extract could inhibit the secretion of the lignin degrading enzyme of C.versicolor and cellulase degrading enzyme secretion of G.trabeum,which effective changed the degrading enzyme system of wood rot fungi.The average reduction of Lignin Peroxidase,Manganese Peroxidase and Laccase from C.versicolor was 84.92% at the concentration of 1.88%.The average reduction of Exoglucanase and Endoglucanase was 89.03% at the concentration of 2.31%.(3)The fractional inhibitory concentration was applied to confirm the antifungal property of the compounds for the Cinnamaldehyde mixed with extract and 3-iodo-2-propynyl-butylcarbamate(IPBC)mixed with extract.The result indicated that there was synergistic antifungal effect against C.versicolor and G.trabeum for the IPBC mixed with extract,and the comprehensive efficacy was improved by 5.26 times.The antifungal property of Cinnamaldehyde mixed with extract was additive effect to against C.versicolor and synergistic antibacterial to against G.trabeum.(4)The mechanical properties of the samples which were bioincied by C.versicolor were significantly changed.And the overall trend of mechanical properties were changed first and then decreased.The permeability of bioincied pieces was analyzed,and the trend of penetration distance was S-type growth.In addition,the FT-IR analysis showed that the C.versicolor selective degraded the composition of P.davidiana sapwood specimens that the degradability of lignin was stronger than cellulose and hemicellulose.(5)In the vivo antifungal experiment of compounded medicament,the average uptake rates of IPBC-extract and Cinnamic aldehyde-burdock were respectively increased by 49.60% and 0.56% comparing with the un-pretreated specimens.And the best uptake of pretreated specimens for the compounds was at 17 days that were increased 89.97% and 16.99%.The antifungal properties of un-pretreated specimens absorbing the single agents(IPBC,Cinnamic aldehyde,extract)and the compound(IPBC-extract,Cinnamic aldehyde-extract)were significantly increased,and the mass loss was about 5% against the C.versicolor comparing with the control.The anti-brown rot fungi property of the specimens dipped by IPBC-extract was increased from the slightly decay resistance to the decay resistance level,and the mass loss rate decreased by 22.52% at 17 days.In addition,the weight loss rate for Cinnamic aldehyde-extract compound was 71.75%,and that was decay resistance grade at 22 days. |
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