【目的】确定引起中国陕、豫两省苹果炭疽病的病原菌种类。【方法】对病原菌进行分离、纯化、致病性测定以及形态学鉴定、rDNA ITS区序列分析、rDNA ITS区特异引物CaInt2/ITS4扩增。【结果】自陕西、河南11个地点采集192份样本,经鉴定引起陕、豫两省苹果炭疽病的病原菌有2种,胶孢炭疽菌[Colletotrichum gloeosporioides(Penz.)Sacc.]和尖孢炭疽菌(C.acutatum J.H.Simmonds)。两种病原菌的区别主要在于分生孢子形态、菌落颜色、对引物CaInt2的特异性等。【结论】首次证实了中国苹果炭疽病可由尖孢炭疽菌(C.acutatum)引起。两种病原菌在陕、豫两省各地区均有分布,其中,胶孢炭疽菌(C.gloeosporioides)所占比例较高。
Objective Determining the possible pathogens of apple fruit bitter rot in Shaanxi and He nan provinces of China.Method The pathogens were isolated and their pathogenicities were determined.Identification was carried out by using traditional morphological methods and sequencing of rDNA-ITS with universal primers and species-specific primer CaInt2.Result One hundred and ninety two samples of diseased apple fruits were collected from eleven locations in Shaanxi and He nan provinces of China.Two fungal species,Colletotrichum gloeosporioides (Penz.) Sacc. and C. acutatum J.H. Simmonds were found as possible pathogens of apple fruit bitter rot in these regions. The two fungal pathogens can be distinguished on the basis of conidial morphology, colony color, growth rate and specific amplification by primers Calnt2/ITS4. [Conclusionl It has been confirmed that the apple fruit bitter rot in China is caused by two fungal species, Colletotrichum gloeosporioides and C. acutatum. Both species were distributed in the districts sampled, but C. gloeosporioides was more often isolated.