【作者】 吴琪；

【导师】 刘淑艳；

【作者基本信息】 吉林农业大学 ， 植物病理学， 2008， 硕士

【摘要】 通过2005～2007近两年时间的基本调查,获得了大连市草坪草主要病害的种类、危害程度、病原物及分布的基本数据,共发现病害9种,鉴定出病原菌9属12种。调查的病害有锈病（Rusts）、弯孢叶枯病（Curvularia Blight）、镰刀枯萎病（Fusarium Blight）、黑孢霉叶枯病（Nigrospora Blight）、白粉病（Powdery Mildew）、禾草离蠕孢叶枯病（Bipolaris Blight）、褐斑病（Brown Patch）、壳针孢叶枯病（Septoria Spot）、壳二孢叶枯病（Ascochyta Blight）;鉴定出的真菌有早熟禾柄锈菌（Puccinia poae-nemoralis）、禾冠锈菌（P.coronata Corda var.coronata）、禾草叶褐锈病菌（Puccinia rubigo-vera）、新月弯孢霉菌（Curvularia lunata）、膝曲弯孢霉菌（Curvularia geniculata）、早熟禾根腐镰孢霉[Fusarium poae（PK.）Wr.]、球黑孢霉[Nigrospora sphaeri（Sacc.）Mason]、禾布氏白粉菌（Blumerea graminis DC.）、禾草离蠕孢（Bipolaris sorokiniana）、立枯丝核菌（Rhizoctonia solani Kvh）,小麦颖枯壳针孢菌（Septoria nodorum）、禾生壳二孢菌（Ascochyta grammicola Sacc）。以上均为大连新纪录,其中黑孢霉叶斑病（Nigrospora Blight）、禾草离蠕孢叶枯病（Bipolaris Blight）、壳针孢叶枯病（Septoria Spot）、壳二孢叶枯病（Ascochyta Blight）为辽宁省病害新纪录种;禾草叶褐锈病菌（Puccmia rubigo-vera）,早熟禾根腐镰孢霉[Fusarium poae（PK.）Wr.]、球黑孢霉[Nigrosporasphaeri（Sacc.）Mason],小麦颖枯壳针孢菌（Septoria nodorum）,禾生壳二孢菌（Ascochytagrammicola Sacc）为辽宁省病原新记录。调查中发现黑孢霉叶斑病的发生呈上升趋势,所以,本文对黑孢霉叶斑病进行了较为系统的研究。现将研究结果介绍如下:2005年七月对大连市的草坪草黑孢霉叶斑病病株采样、分离纯化,并对其病原菌形态、生物学特性、致病性等方面进行测定。依据柯赫氏证病法和有关材料进行鉴定,确认为球黑孢霉菌[Nigrospora sphaerica（Sacc.）Mason]。对球黑孢霉进行了生物学特性研究。结果表明,球黑孢霉菌丝生长的温度范围在10～35℃,孢子萌发温度范围为5～40℃。菌丝生长及产孢的最适温度均为25℃;孢子萌发的最适温度为28℃,24h萌发率高达89.2%。在12h光暗交替条件下菌落生长量最大,孢子萌发率也最高,而8h黑暗16h光照处理的菌落直径最小;连续光照的产孢量最大为82.43×10⁶个/mL,连续黑暗产孢量最小为38.96×10⁶个/mL。病原菌生长的pH范围为3.0～11.0,而pH 4.0～9.0最适合生长,pH3.0～9.0范围内均能产孢,pH=6.32时球黑孢霉产孢量最大,为7.24×10⁶个/mL。菌落生长的最佳碳源是果糖,3d后的菌落直径为62.77mm;在2%的蔗糖和葡萄糖中球黑孢霉的分生孢子萌发率较高,分别为79.83%和78.63%,而在2%的半乳糖和甘露糖中球黑孢霉的分生孢子萌发率较低,分别为40.47%和38.27%,在蔗糖中产孢量最大,为8.70×10⁶个/mL。果糖是促进病菌生长和孢子形成的良好碳源,而琼脂糖既不利于菌落生长又不利于产孢。在不同的氮源中,硝酸铵有利于球黑孢霉的生长,3d后的菌落直径为65.73mm,而氯化铵有利于孢子的形成,在CK中球黑孢霉的分生孢子萌发率最高为79.8%,而在氯化铵中病原菌分生孢子萌发率最低为22.8%。L-谷氨酸既不利于病菌生长也不利于产孢。球黑孢霉分生孢子在水滴和100%的空气湿度时,其孢子萌发率均在99%以上,当湿度低于90%时,分生孢子的萌发率迅速由85%降至20%,在空气湿度为70%时,病菌分生孢子则不能萌发。胡萝卜培养基有利于菌落生长,培养3d的菌落直径为62.83mm。利用含毒介质法对11种化学药剂进行室内毒力测定,结果表明:70%甲基硫菌灵（thiophanate-methyl）、50%代森锰锌（Mancozeb）、75%百菌清（Daconil）、50%多菌灵（Carbendazim）在100mg/L浓度下抑菌效果十分明显,多菌灵对球黑孢霉的抑菌率最高,达到100%。选取这四种药剂配置不同浓度梯度的含药培养基,进行抑菌试验,制作毒力回归方程。四种药剂的EC₅₀值分别为4.5663mg/L、8.3740mg/L、9.1625mg/L、10.0440mg/L。更多还原

【Abstract】 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.更多还原