引起I-107杨树溃疡病的病原菌大孢不高双胞菌的研究

2008年4月～2011年6月，通过对I-107杨溃疡病病原分离、野外接种致病性测定试验、病原菌的形态观察及ITS序列分子鉴定，结果表明，该病的病原菌鉴定为大孢不高双胞菌，在我国的杨树上属于首次报道，由它引起I-107杨溃疡病为杨树新病害。野外接种1年生I-107杨树幼苗，10天后的发病率为100％；该病原菌的分生孢子器为黑色，分生孢子梗缺；产孢细胞瓶梗状，无色，4．5～9．6μm×4．5—7．4μm；分生孢子圆柱形到长圆形，或窄卵圆形，成熟的分生孢子有2个细胞，无色，基部细胞窄，顶部细胞略宽，分隔处缢缩，2个细胞的分生孢子比单细胞的分生孢子更大，23．1—31．6Iμm×6．7～9．8μm，平均为27．7μm×8．9μm；未成熟的分生孢子为单细胞，16．5—26．1μm×6．2—8．5μm，平均为22．7μm×8．9μm。

Study on Canker of Populus x euramericana CL ＇74/76＇ Caused by Apiocarpella macrospora

Canker fungus of Populus x euramericana CL ＇ 74/76＇ was isolated in laboratory, inoculated pathoge- nicity tests in field, morphological observation of pathogenic fungus and ITS sequences identification were also car- ried out from April 2008 to June 2011. The results show that the pathogenic fungus is identified as Apiocarpella ma- crospora, which is reported for the first time and also a new disease on the poplar in China. One-year poplar seed- lings are inoculated in field and then the incidence is 100 % after ten days. Pycnidia of the pathogenic fungus is black, conidiophores absent; conidiogenous cell is phialide, hyaline, 4.5 - 9.6 μm× 4.5 - 7.4 μm. Conidia are cylindrical to long circle, or narrow ovoid in shape, mature conidia have 1 euseptate, hyaline, narrow base cells, apex cells slightly wide, constriction at separating. Two cell conidia are larger than one cell conidia, 23.1 -31.6 μm×6. 7 -9. 8 μm, average 27.7μm ×8.9 μm. Immature eonidia are lcell, 16. 5 ~26. 1 μm x6. 2 × 8.5μm, average 22.7 μm ×8.9 μm.