陕西线辣椒炭疽病原菌的鉴定及生物学特性研究
Identification and Biological Characterization of Anthrax Bacteria in Xianlajiao Chili Pepper in Shaanxi Province

为了搞清陕西省线辣椒主产区炭疽病的致病菌类型及其主要生物学特性，对采自陕西省宝鸡市线辣椒主产区具有炭疽病症状的80份线辣椒果实样品进行致病病原菌分离、鉴定、主要生物学特性研究及多基因联合分析。结果表明，从80份病样中共鉴定出4种不同的炭疽菌，即尖孢炭疽菌（Colletotrichum acutatum）、大豆炭疽菌（Colletotrichum truncatum）、菠菜炭疽菌（Colletotrichum spinaciae）和博宁炭疽菌（Colletotrichum boninense），4种炭疽菌所占比率依次为83.75%、13.75%、1.25%和1.25%；尖孢炭疽菌对线辣椒的致病力最强，其次是大豆炭疽菌，菠菜炭疽菌对线辣椒致病力较弱，博宁炭疽菌对线辣椒没有致病力。生物学特性研究表明，温度25 ℃、连续光照、pH=6、碳源葡萄糖、氮源酵母浸膏最适合尖孢炭疽菌菌丝生长，温度30 ℃、连续光照、pH为5～6、碳源麦芽糖、氮源酵母浸膏最适合尖孢炭疽菌菌株产孢；温度30 ℃、连续光照、pH为7、碳源果糖、氮源蛋白胨最适合大豆炭疽菌菌丝生长，温度30 ℃、连续黑暗、pH为5～6、碳源麦芽糖、氮源脯氨酸最适合大豆炭疽菌菌株产孢；温度30 ℃、连续光照、pH为9~11、碳源麦芽糖、氮源蛋白胨最适合菠菜炭疽菌菌丝生长；温度30 ℃、连续黑暗、pH为5～6、碳源麦芽糖、氮源蛋白胨最适合菠菜炭疽菌菌株产孢。在陕西省线辣椒上发现尖孢炭疽菌，为首次报道；在辣椒上发现菠菜炭疽菌，亦为首次报道。
In order to determine the types and biological characteristics of anthrax bacteria in Xianlajiao chili pepper in Shaanxi province,80 pepper fruit samples with anthracnose symptoms were collected from Baoji,the main production area of Xianlajiao Chili pepper in Shaanxi province and the pathogens were isolated and identified biological characteristics and sequence analyzed using Multi-gene combination method .The results showed that four different types of anthrax strain were identified from 80 samples,including Colletotrichum acutatum,Colletotrichum truncatum,Colletotrichum spinaciae,and Colletotrichum boninense,and their proportion were 83.75%,13.75%,1.25% and 1.25% respectively,C.acutatum presented the strongest virulence to Xianlajiao pepper fruit,followed by C.truncatum and C.spinaciae with weak pathogenicity,but C.boninense was avirulence.The study of the biological characteristics analysis displayed the optimal environment and medium conditions for the hypha growth and spore production for every type of anthrax bacteria.For C.acutatum,the optimal conditions for hypha growth included environment condition of 25 ℃ temperature,continuous illumination,and medium with pH 6,glucose for carbon source,yeast extract for nitrogen source,the optimal conditions for spore production included environment condition of 30 ℃ temperature,continuous illumination,and medium with pH 5-6,maltose for carbon source,yeast extract is for nitrogen source.For C.truncatum,the optimal conditions for hypha growth and spore production were 30 ℃,continuous illumination,pH 7,fructose,peptone,and 30 ℃,continuous darkness,pH 5-6,maltose,proline,respectively.For C.spinaciae,the optimal conditions for hypha growth and spore production were 30 ℃,continuous illumination,pH 9-11,maltose,peptone,and 30 ℃,continuous darkness,pH 5-6,maltose,peptone,respectively.This is the first report about the identification of C.acutatum in Xianlajiao chili