Biological characters and rDNA ITS sequences of pathogen of poplar leaf blight

脱氧核糖核酸用一个修改 CTAB 方法从白杨叶老家的病原体的紧张被提取。它的顺序(601bp ) 被使用通用教材 ITS1 和 ITS4 开始从病原体放大(登记没有。DQ011257 ) 。比作核苷酸序列从 GenBank 获得了数据库，紧张与 Alternariaalternate (AY787684 ) 被聚类进同质， Al-ternaria 轮流出现(AY354228 ) 与 98% 的相同，因此，紧张作为 Alternaria alternata (Fr ) 被检查 Keissler。为 conidia 萌芽和病原体的菌丝体生长的最佳的条件被测试。为 conidia 发芽和菌丝体生长的最佳的温度是 25 ℃，并且最佳的 pH 是 6。菌丝体在 10 ℃ and30 ℃相当慢慢地成长，生长在上面停止 35 ℃。在测试的六培养基之中， PDA + 白杨叶果汁媒介为菌丝体生长是很有利的。

DNA was extracted from the strain of pathogen of poplar leaf blight using a modified CTAB method. ITS sequence （601bp） was initially amplified from the pathogen by using the universal primers ITSl and ITS4 （registered No, DQ011257）. Comparing to the nucleotide sequences acquired from GenBank database, the strain is clustered into the homogeneity with Alternaria alternate （AY787684） and Alternaria alternate （AY354228）, with a homology of 98%, thus the strain was checked as Alternaria alternata （Fr.） Keissler. The optimal conditions for conidia germination and mycelium growth of the pathogen were tested, The optimal temperature for conidia germinating and mycelium growth is 25℃, and the optimal pH value is 6. Mycelium grows rather slowly at 10℃ and 30℃ and growth stops at above 35 ℃. Among the six culture mediums tested, PDA ＋ poplar leaf juice medium is most favorable for mycelium growth.