Dai F M, Ren X J, Lu J P
Institute of Plant Protection, Shanghai Key Lab of Protected Horticultural Technology, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China.
Plant Dis. 2006 Nov;90(11):1460. doi: 10.1094/PD-90-1460A.
In 2004, fruits showing dark and sunken necrotic lesions were observed on strawberries (Fragaria × ananassa Duch. cv. Mei No. 3) in a field in Shanghai, China. All isolates obtained from the infected fruits easily produced orange spore masses and developed orange colonies with orange reverse colony color; none formed setae or the ascigerous stage in culture or on the host. The conidia were hyaline, straight and fusiform, 8 to 16 × 2.5 to 4 μm, and produced melanized, ellipsoid, ball- or pear-shaped appressoria at the end of germ tubes. These isolates were similar to those described for Colletotrichum acutatum J. H. Simmonds. To confirm pathogenicity of the isolate, inoculum suspension with 4 × 10 conidia/ml was sprayed onto 10 fruiting strawberry plants until runoff. The inoculated plants were maintained at 25°C and 100% relative humidity in a growth chamber with a 12-h period of fluorescent light daily. Plants inoculated with sterilized water were controls. After 3 days, dark brown lesions appeared in the leaves, petioles, and fruits of all inoculated plants. The symptoms were similar to those observed on the strawberry fruit from which the isolate was originally isolated. The pathogen was consistently reisolated from the symptomatic fruit. No symptoms were observed on the control plants. To our knowledge, this is the first report of C. acutatum as the casual agent of anthracnose fruit rot of strawberry in China.
2004年，在中国上海的一块田地里，人们观察到草莓（Fragaria × ananassa Duch. cv. Mei No. 3）果实上出现了深色且凹陷的坏死斑。从感染果实上分离得到的所有菌株很容易产生橙色孢子堆，并形成橙色菌落，菌落背面呈橙色；在培养物中或寄主上均未形成刚毛或子囊阶段。分生孢子透明、直且呈梭形，8至16×2.5至4μm，在芽管末端产生黑化的、椭圆形、球形或梨形附着胞。这些菌株与尖孢炭疽菌（Colletotrichum acutatum J. H. Simmonds）描述的菌株相似。为了证实该菌株的致病性，将含有4×10个分生孢子/毫升的接种悬浮液喷洒到10株结果期草莓植株上，直至径流。接种后的植株在生长室中保持在25℃和100%相对湿度，每天有12小时的荧光光照。用灭菌水接种的植株作为对照。3天后，所有接种植株的叶片、叶柄和果实上出现深褐色病斑。症状与最初分离该菌株的草莓果实上观察到的症状相似。病原菌始终能从有症状的果实上重新分离得到。对照植株未观察到症状。据我们所知，这是尖孢炭疽菌作为中国草莓炭疽病果实腐烂病原菌的首次报道。
