Tozze H J, Massola N M, Câmara M P S, Gioria R, Suzuki O, Brunelli K R, Braga R S, Kobori R F
Departamento de Entomologia, Fitopatologia e Zoologia Agrícola, ESALQ/USP, CP9, 13418-900, Piracicaba, SP, Brazil.
Departamento de Agronomia, UFRPE, Dois Irmãos, 52171-900, Recife, PE, Brazil.
Plant Dis. 2009 Jan;93(1):106. doi: 10.1094/PDIS-93-1-0106A.
Colletotrichum boninense was isolated from pepper (Capsicum annuum) fruits (cv. Amanda) with preharvest anthracnose symptoms collected in the Brazilian states of Rio Grande do Sul and São Paulo in July of 2005. In the field, the disease affected mature fruits and leaves with an incidence near 25%. Typical symptoms in fruits were circular, sunken lesions with orange spore masses in a dark center. Three single conidia isolates were obtained from infected fruits. When grown on potato dextrose agar at 25°C with a 12-h photoperiod, these isolates produced white colonies with a cream-to-orange color in the opposite side, but no sclerotia. Conidia were cylindrical, had obtuse ends and a hilum-like low protuberance at the base, and measured 13.5 to 15.5 × 4.6 to 5.1 μm. Conidial length/width ratio was 2.8 to 3.0. These morphological characteristics are consistent with the description of C. boninense (1). To confirm pathogen identity, the internal transcribed spacer rRNA region was sequenced (GenBank Accession Nos. FJ010199, FJ010200, and FJ010201) and compared with the same region of C. boninense (GenBank Accession No. DQ286160.1). Similarity between these sequences was 98 to 99%. The pathogenicity of the three isolates was determined on pepper fruits cv. Amanda. Attached as well as detached fruits from potted plants were inoculated. Inoculation was performed by depositing 40-μl droplets of a suspension (10 conidia per ml) on the surfaces of nonwounded (detached n = 5; attached n = 5) and wounded (detached n = 5; attached n = 5) fruits with a sterilized hypodermic needle. Incubation took place in a moist chamber for 12 days at 25°C with a 12-h photoperiod. Inoculation of control fruits was similar in procedure and number to that of test fruits, except sterile distilled water was used instead of the conidial suspension. Symptoms, observed in wounded and nonwounded test fruits 3 to 5 days after inoculation, were characterized by necrotic, sunken zones containing acervuli, black setae, and orange spore masses. Control fruits presented no symptoms. Pathogens reisolated from infected fruits showed the same morphological and molecular characteristics of the isolates previously inoculated. To our knowledge, this is the first report of C. boninense infecting pepper in Brazil. Reference: (1) J. Moriwaki et al. Mycoscience 44:47, 2003.
2005年7月，从巴西南里奥格兰德州和圣保罗州采集的具有采前炭疽病症状的辣椒（品种阿曼达）果实中分离出了博宁炭疽菌。在田间，该病影响成熟果实和叶片，发病率接近25%。果实上的典型症状是圆形、凹陷的病斑，中央深色，有橙色孢子堆。从受感染果实中获得了三个单分生孢子分离株。当这些分离株在25°C、12小时光周期的马铃薯葡萄糖琼脂上生长时，形成白色菌落，背面呈奶油色至橙色，但不产生菌核。分生孢子呈圆柱形，两端钝圆，基部有类似脐的低突起，大小为13.5至15.5×4.6至5.1μm。分生孢子长宽比为2.8至3.0。这些形态特征与博宁炭疽菌的描述一致。为了确认病原菌的身份，对其内部转录间隔区rRNA区域进行了测序（GenBank登录号：FJ010199、FJ010200和FJ010201），并与博宁炭疽菌的同一区域（GenBank登录号：DQ286160.1）进行了比较。这些序列之间的相似性为98%至99%。在辣椒品种阿曼达的果实上测定了这三个分离株的致病性。对接种盆栽植物上的附着果实和离体果实进行了接种。接种方法是用无菌皮下注射针将40μl悬浮液（每毫升含10个分生孢子）滴在未受伤（离体n = 5；附着n = 5）和受伤（离体n = 5；附着n = 5）的果实表面。在25°C、12小时光周期的保湿箱中培养12天。对照果实的接种程序和数量与试验果实相似，只是用无菌蒸馏水代替分生孢子悬浮液。接种后3至5天，在受伤和未受伤的试验果实上观察到的症状表现为坏死、凹陷区域，含有分生孢子盘、黑色刚毛和橙色孢子堆。对照果实未出现症状。从受感染果实中重新分离出的病原菌表现出与先前接种的分离株相同的形态和分子特征。据我们所知，这是博宁炭疽菌在巴西感染辣椒的首次报道。参考文献：(1) J. Moriwaki等人，《真菌科学》44:47，2003年。
