烟草灰霉病病原鉴定及其生物学特性

Identification and evaluation in biological characteristics of tobacco grey mould pathogen

对广西烟草灰霉病的病原、生物学特性进行了初步的研究。根据该病原菌的形态特征、致病性及rDNA-ITS序列测定,将该病原菌鉴定为灰葡萄孢(Botrytis cinerea Pers)。该病原菌菌丝在5℃-30℃的温度范围内均可生长,产生分生孢子的温度范围为10℃-25℃,菌核形成温度范围为15℃-22.5℃,最适温度均为20℃;分生孢子萌发的温度范围为7.5℃-30℃,最适温度为20℃-25℃。在pH 2-9的范围内该菌均能生长,最适pH为6。分生孢子需在高湿条件下才能萌发,相对湿度低于100%时不能萌发。完全光照对该菌菌丝生长有促进作用,而完全黑暗更利于产孢、孢子萌发及菌核的形成。单糖及双糖、有机氮及硝态氮是病原菌较好的C、N源。分生孢子和菌核的致死温度分别是42℃和46℃。

Tobacco grey mould pathogen in Guangxi and its biological characteristics were identihed and prehmmarily studied. Botrytis cinerea Pers was suggested based on morphology, pathogenicity and analysis of sequences of ribosome rDNA-ITS. For mycelia growth, sporulation, and sclerotium formation, temperature ranged from 5 ℃ to 30℃, IO℃ to 25℃, and 15℃ to 22.5℃ respectively, with optimum temperature of 20℃. For conidial germination, range of tempera- ture was 7.5℃-30℃, and the optimum temperature was between 20℃-25℃. The range of pH for mycelia growth was between 2-9, and the optimum pH was 6. Conidia did not germinate in condition of relative humidity bellow 100%. Flu-orescent light could promote mycelia growth, but the darkness was suitable for sporulation, conidial germination, and sclerotium formation. Monosaccharides and disaccharides, and organic nitrogen and nitrate were better sources of C and N, respectively. The lethal temperature for the spores and the sclerotium was 42℃ and 46℃, respectively.