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The basic data of main turfgrass diseases,damage degree,pathogen and their distribution in Dalian City were obtained by the survey during 2005～2007.Nine diseases were found,12 species of pathogen which belonging to 9 genus were identified.They were Rusts,Curvularia Blight,Fusarium Blight,Powdery Mildew, Bipolaris Blight,Brown patch,Septoria Spot,Ascochyta Blight;Fungi were identified as Puccinia poae-nemoralis,P.coronata Corda var.coronata,Puccinia rubigo-vera,Curvularia lunata,Curvularia geniculata,Fusarium poae（PK.）Wr.,Nigrospora sphaeri（Sacc.） Mason,Blumerea graminis DC.,Bipolaris sorokiniana,Rhizoctonia solani Kvh,Septoria nodorum,Ascochyta graminicola Sacc.Above were new records in Dalian City.Among them,Nigrospora Blight,Curvularia Blight,Bipolaris Blight,Septoria spot, Ascochyta Blight were new records in Liaoning province.Nigrospora Blight occured more and more severe which has been researched very little in our country at present.So systematic studies on Nigrospora Blight was done in this paper.The results as follows:The disease turfgrass leaves were collected in Dalian in July,2005 and the fungus was isolated on PDA and purified by single spore isolation.Based on the Koch’s postulates method,the pathogen of turfgrass nigrospora blight was identified as Nigrospora sphaerica（Sacc.） Mason.The results of the biological studies on Nigrospora sphaerica showed that the favorable temperature for mycelia growth and conidia germination is at 10～35℃and the optimal temperature was 25℃for mycelia growth and conidia production.The optimal temperature for spore germination was 28℃;rate of conidial germination in 24h was 89.2%;the optimum temperature for sporogenesis was 28℃and Nigrospora sphaerica did not produce spores at lower than 5℃.Fungus grew well and the rate of spore germination was high under the treatment of 12h alternation of darkness and light.The colony diameter was smallest under 16h darkness and 8h light.In the continuously dark condition the spores were produced greatly up to 82.43×106 /mL,and in the continual illumination condition the spores were produced less to 38.96×106/mL.The hypha grew well at pH 3.0～11.0,and the pH4.0～9.0 was the optimal.The spores could be produced at pH3.0～9.0 and reached to the top,7.24×106/mL,at pH=6.32.Best carbon resources was fructose and the colony diameter was 62.77mm 3 days after inoculation;The rate of conidia germination was 79.83%in 2%saccharose and 78.63%in dextrose,both of which were higher than in the other carbon sources.The lowest rate of conidia germination was 40.47%and 38.27%in galactose and amrita.The highest sporulation was 8.70×106/mL in 2%saccharose.The fructose was the best carbon source for mycelia growth and sporulation.But agarose inhibited hyphae growth and sporulation.Among different nitrogen sources,NH4NO3 performs better for mycelia growth and the colony diameter was 65.73mm in 3 days.The highest rate of conidia germination was 79.8%in CK and the lowest was 22.8% in NH4CL.L-Glutamic reduced hyphae growth and sporulation.Nigrospora sphaerica conidia when the waterdrop and 100%relative humidity,its spore germination rate above 99%,when the relative humidity is lower than 90%,the conidia germination rate to 85%to drop to 20%rapidly,when the relative humidity is 70%,the germ minute lives the spore not to be able to sprout.The carrot culture medium was advantageous in the colony grows,raises 3 day-long colony diameter was 62.83mm.The toxicity of eleven fungicides and its concentrations were determined by testing the conidial germination rate and colony growth.The results indicated that conidia germination was effectively inhibited by 50%Carbendazim,75%Daconil,50%Mancozeb,70%thiophanate-methyl in100mg/L concentration.The best effect reached to 100%by Carbendazim.The EC50 of the four kinds of fungicides were 4.5663mg/L、8.3740 mg/L、9.1625 mg/L、10.0440 mg/L individually.
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