Biological Characteristics And Optimize The System Of Agrobacterium Tumefaciens Mediated Transformation Of Aureobasidium Zeae

Maize eyespot,caused by Aureobasidium zeae is the one of important leaf diseases.At present,disease occurrence,typical symptom description of maize eyespot were reported but molecular pathogenesis mechanism of A.zeae has not been reported.Morphological characteristics of Aureobasidium zeae were studied by crossing method and hemocytometer;differential hosts of A.zeae to idenifing virulence and strong pathogenic strain were screened,and the classification standard of this disease was defined;ATMT of Aureobasidium zeae was established and optimized,and morphological characteristics and pathogenicity of transformants were obsevede Those results could revealed the pathogenesis mechanism of A.zeae.The main results were as follows:1.Isolation and identification pathogenic fungal of maize eyespot diseaseAureobasidium zeae,caused maize eyespot disease was identified by morphological and molecular method,indicated Aureobasidium zeae(Narita et Hiratsuka)Dingley causing maize eye spot disease2.The biological characteristics of A.zeaeA.zeae could grow under 15-30?,with optimal condition at 25?,pH 7,dark,sucrose,potassium nitrate,PDA,and the largest sporulation quantity at 25?,pH 7,dark,glucose,and the largest conidia germination at 28?,pH 8,alternating light and dark,maltose,beef extract.No conidia production of A.zeae was observed by adding different nitrogen sources into water agar plates and conidia germination was inhibited by adding single nitrogen source.3.Pathogenicity differentiation of A.zeaeA total of 78 strains of A.zeae were isolated from different provinces of China.Six inbred lines were screened as differential hosts of A.zeae to idenifing virulence by inoculating key t maize inbred-line.A.z-01 was strong pathogenic strain by morphological characteristics observation and inoculation differential hosts.4.Established and optimized the condition of ATMTThe transformation system of A.zeae was optimized.The concentration of condia of A.zeae for 106·mL-1 and the concentration of Agrobacterium AGL-1 OD600=0.6 were blended at ratio 3:1,Induction time was 1h,for 2 d in 25?.The efficiency of transformation is 142/106 mL-1.350 transformants were obtained by using the system.5.Morphological observation and pathogenicity analysis of mutantAccording to colony morphology of the transformants on PDA,the transformants were divided into 5 types,and the pathogenicity of transformants were analyzed,the most transformants could infect maize leavests after inoculation,the lesion was mainly divided into 5 types,and then mutants isolated could flow green fluorescence by fluorescence microscopy observation.