对采自安徽油菜黑胫病菌分离株的ITS序列进行了测定和分析,结合GenBank中的有性型Leptosphaeriamaculans和Leptosphaeria biglobosa的ITS序列构建了系统发育树,将该病菌鉴定为Leptosphaeria biglobosa。在人工气候条件下,对Leptosphaeria biglobosa侵染条件的研究表明,油菜黑胫病菌是属偏高温高湿类型的病害,在温湿度条件不能得到满足时,病害就难以完成侵染发病|温度与保湿时间对Leptosphaeria biglobosa的侵染有很大的影响,病原菌侵染的最佳温度和保湿时间组合为:温度21～24℃,保湿48 h以上。保湿48 h以下,随着保湿时间的减少及培养温度的降低或升高,病情指数均降低|但在12～72 h各保湿梯度内,随培养温度由15～21℃上升,病情指数逐渐升高,而随培养温度由21～27℃上升,病情指数逐渐降低。
The species identity of the pathogen of Phoma stem canker was determined through a combined study of rDNA-ITS sequences. Phylogenetic analysis showed that the isolate clustered together with the isolates of Lepto-sphaeria biglobosa and was distinct from those of Leptosphaeria maculans. ITS sequence analysis indicated the isolate was Leptosphaeria biglobosa. Infection conditions and pathogenicity of Leptosphaeria biglobosa were conducted in controlled environment. The studies indicated that blackleg of oilseed rape frequently occurred under high tempera-ture and high humidity conditions and the pathogen couldn't infect the host when temperature and humidity were unsuitable;Temperature and wetness period cangreatly affect the infection of Leptosphaeria biglobosa,at 21-24℃ with over 48 h of wetness period was the favorite combination of temperature and wetness period for infection,below 48 h of wetness period,disease index decreased with decreasing wetness period and increasing or decreasing temper-ature. As wetness period from 12-72 h,disease index increased with temperature increasing from 15-21℃,but it reduced with temperature increasing from 21-27℃.
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