苎麻胶孢炭疽菌生物学特性的研究

Biological characters of the ramie anthracnose pathogen Colletotrichum gloeosporioides

本研究以苎麻炭疽菌(Colletotrichum gloeosporioides)为研究对象,主要研究了温度、pH、培养基成分、碳源和氮源、维生素和光照等因素对病原菌菌丝生长速率和产孢量的影响。结果表明,该菌菌丝生长的温度范围为10~40℃,生长最适温度为25℃。菌丝在pH为3.0~12.0的PDA培养基中均能生长。不同培养基对菌丝生长速率的测试显示,该菌在PDA上生长最快,该菌对各种碳源利用能力不同,其中对麦芽糖的利用率最高。另外,用PDA进行培养,分生孢子生成的温度范围为10~40℃,最适28℃。用不同培养基进行培养,牛肉膏培养基上产孢最多。相同的氮源、碳源不同其产孢量差异很大,硝酸钾和葡萄糖培养基中产孢效果更好。添加维生素B2的液体培养基里可以获得较大的生物量,同时可诱导大量分生孢子的产生。菌丝在12小时光暗交替条件下生长最快,但是分生孢子产量低,而连续黑暗培养更利于分生孢子的生成。本研究结果将为苎麻炭疽病的发生规律、苎麻炭疽病的生物防治和致病机理的研究提供理论基础和依据。

In this study,the effects of temperature,pH,medium composition,carbon and nitrogen sources,vitamins and light on the growth rate and sporulation of ramie anthracnose fungus(Colletotrichum gloeosporioides)were primarily investigated.The results showed that the temperature range for mycelial growth was 10~40℃,and the optimum temperature was 25℃.The fungus could grow on PDA medium at pH 3.0~12.0 and grew fastest on PDA medium.The pathogen under study varied in its ability to utilize different carbon,and maltose was found to be the best source of carbon for the growth.In addition,the it preferred temperature range of 10℃to 40℃for the sporulation when grown on PDA medium,and the optimum temperature for sporulation was 28℃.Maximum production of conidia was observed in the beaf extract medium.Among the carbon sources tested,the pathogen sporulated better in media containing glucose and potassium nitrate.The growth medium supplemented with vitamin B2 resulted in a larger mycelial biomass and producing a large number of conidia.Mycelium grew fastest under conditions of alternating 12-hour intervals of dark and light,but the yield of conidia was low,and continuous dark culture was more conducive to the formation of spores.The results provide a theoretical basis for the occurrence of ramie anthracnose,biological control and the pathogenic mechanism.