Diao Y Z, Fan J R, Wang Z W, Liu X L
Department of Plant Pathology, China Agricultural University, Beijing 100193.
Plant Dis. 2013 Jan;97(1):138. doi: 10.1094/PDIS-04-12-0403-PDN.
Anthracnose, caused by Colletotrichum spp., is a severe disease and results in large losses in pepper (Capsicum frutescens) production in China (4). Colletotrichum boninense is one of the Colletotrichum species in pepper in China. In August 2011, anthracnose symptoms (circular, sunken lesions with orange to black spore masses) were observed on pepper fruits in De-Yang, Sichuan Province, China. Three single-spore isolates (SC-6-1, SC-6-2, SC-6-3) were obtained from the infected fruits. A 5-mm diameter plug was transferred to potato dextrose agar (PDA); the isolates formed colonies with white margins and circular, dull orange centers. The conidia were cylindrical, obtuse at both ends, and 10.5 to 12.6 × 4.1 to 5.0 μm. The colonies grew rapidly at 25 to 28°C, and the average colony diameter was 51 to 52 mm after 5 days on PDA at 25°C. Based upon these characters, the causal agent was identified as C. boninense. To confirm the identity of the isolates, the internal transcribed spacer (ITS) regions were amplified with the ITS1/ITS4 universal primers (1). The internal transcribed spacer (ITS) sequences (Accession No. JQ926743) of the causal fungus shared 99 to 100% homology with ITS sequences of C. boninense in GenBank (Accession Nos. FN566865 and EU822801). The identity of the causal agent as C. boninense was also confirmed by species-specific primers (Col1/ITS4) (2). In a pathogenicity test, five detached ripe pepper fruits were inoculated with 1 μl of a conidial suspension (10 conidia/mL) or five fruits with 1 μl of sterile water were kept as control. After 7 days in a moist chamber at 25°C, typical anthracnose symptoms had developed on the five inoculated fruits but not on control fruits. C. boninense was reisolated from the lesions, and which was confirmed by morphology and molecular methods as before. There have reports of C. boninense infecting many species of plants, including pepper (3). To our knowledge, this is the first report of C. boninense causing anthracnose on pepper in China. References: (1) A. K. Lucia et al. Phytopathology 93:581, 2002. (2) S. A. Pileggi et al. Can. J. Microbiol. 55:1081, 2009. (3) H. J. Tozze et al. Plant Dis. 93:106, 2009. (4) M. L. Zhang. J. Anhui Agri. Sci. 2:21, 2000.
由炭疽菌属（Colletotrichum spp.）引起的炭疽病是一种严重病害，给中国的辣椒（Capsicum frutescens）生产造成了巨大损失（4）。瓜哇炭疽菌（Colletotrichum boninense）是中国辣椒上的炭疽菌种类之一。2011年8月，在中国四川省德阳市的辣椒果实上观察到炭疽病症状（圆形、凹陷病斑，带有橙色至黑色的孢子堆）。从受感染果实中获得了三个单孢分离株（SC - 6 - 1、SC - 6 - 2、SC - 6 - 3）。将一个直径5毫米的菌块转移至马铃薯葡萄糖琼脂（PDA）培养基上；这些分离株形成的菌落边缘白色，中心呈圆形、暗橙色。分生孢子呈圆柱形，两端钝圆，大小为10.5至12.6×4.1至5.0微米。菌落在25至28°C下生长迅速，在25°C的PDA培养基上培养5天后，平均菌落直径为51至52毫米。基于这些特征，确定病原菌为瓜哇炭疽菌。为了确认分离株的身份，使用ITS1/ITS4通用引物扩增了内部转录间隔区（ITS）区域（1）。致病真菌的内部转录间隔区（ITS）序列（登录号JQ�26743）与GenBank中瓜哇炭疽菌的ITS序列（登录号FN566865和EU822801）具有99%至100%的同源性。通过种特异性引物（Col1/ITS4）（2）也证实了病原菌为瓜哇炭疽菌。在致病性试验中，用1微升分生孢子悬浮液（10个分生孢子/毫升）接种5个离体成熟辣椒果实，另外5个果实接种1微升无菌水作为对照。在25°C的保湿箱中放置7天后，5个接种果实上出现了典型的炭疽病症状，而对照果实未出现症状。从病斑上重新分离出瓜哇炭疽菌，并如前所述通过形态学和分子方法进行了确认。有报道称瓜哇炭疽菌可感染多种植物，包括辣椒（3）。据我们所知，这是瓜哇炭疽菌在中国引起辣椒炭疽病的首次报道。参考文献：（1）A. K. Lucia等人，《植物病理学》93:581，2002年。（2）S. A. Pileggi等人，《加拿大微生物学杂志》55:1081，2009年。（3）H. J. Tozze等人，《植物病害》93:106，2009年。（4）M. L. Zhang，《安徽农业科学》2:21，2000年。
