The Isolation And Identification Of Pathogen And Prevention Test To Botrytis Cinerea On Aquilaria Sinensis

Aquilaria sinensis（Lour.）Gilg is a national level two rare and endangered plant、a national level two key protected wild plant.Up to now,about 76000 aquilaria trees have been introduced and cultivated from Zhuhai,Guangdong Province in Mingwei Township,Yibin City,Sichuan Province.However,in recent years,the occurrence of Botrytis cinerea is more frequent,seriously affecting its growth and economic value,bring a great loss to the local area.In this paper,Aquilaria sinensis trees were investigated from Yibin city in Sichuan province.To observe the morphological characteristics of the pathogen of Botrytis cinerea of Aquilaria sinensis on the branches.In accordance with organizational separation,the pathogen was purified by pure culture strains.Through the morphological and molecular biological identification of pathogenic bacteria,Botrytis cinerea was identified as a pathogen.In order to discuss the growth and spore germination conditions,the biological characteristics of pathogen were further studied.In the antagonistic test,compared with different antagonistic bacteria on the pathogenic bacteria inhibitory effect.Combined with field control technology,the indoor efficacy test was looking for pesticides which had a better effect on the inhibition of pathogen,and then applied to the field trials.The results of the study are as follows:There are differences in the growth rate of pathogenic bacteria on the five different media,and PDA medium is the most suitable for hypha growth.The optimum temperature for spore germination and mycelial growth was 25℃,and the optimum pH was 6.0.Mycelium grew fastest under the full light conditions.Among the tested carbon and nitrogen sources,suitable for the growth of carbon sources were sucrose and fructose,nitrogen source were peptone and beef extract.The higher the relative humidity,the higher the rate of germination of Botrytis cinerea,Botrytis cinerea germinated highest in the nutrient solution containing lactose.Three kinds of antagonistic bacteria were selected to test the antagonistic effect of the tested bacteria.Plate confrontation test showed that the three kinds of antagonistic bacteria on the growth of mycoplasma had some inhibition.The inhibitory rate of Bacillus subtilis,Trichoderma viride and Trichoderma harzianum on mycelial growth of pathogenic bacteria were 51.88%,77.26%and 80.82%,respectively.Ten kinds of fungicides were selected for the indoor toxicity test,the results showed that70%mancozeb WP,50%iprodione WP,70%thiophanate-methyl WP,50%pyrethrin WP and50%carbendazim WP had better inhibitory effect on the mycelial growth of pathogen,and the inhibition rate increased with increasing drug concentration.However,the toxicity of each agent to pathogenic bacteria was significant,with EC₅₀0 of 3ug/mL,1.65ug/mL,1.31ug/mL,1.20ug/mL and 0.64ug/mL,respectively.And then 100%cfu/g Trichoderma harzianum WG,50%carbendazim WP and 50%procymidone WP were selected for field efficacy trials.The results showed that before and after treatment of these three kinds of medicaments,there was a certain control effect but no significant difference.