Riccioni L, Conca G, Hartman G L
Istituto Sperimentale per la Patologia Vegetale, via C.G. Bertero 22, I-00156 Rome, Italy.
USDA, ARS, 1101 W. Peabody Drive, Urbana, IL 61801.
Plant Dis. 1998 Aug;82(8):959. doi: 10.1094/PDIS.1998.82.8.959C.
Anthracnose symptoms were observed on soybean (Glycine max (L.) Merr.) cv. Yale in Illinois in September 1996. Lower stems were girdled by lesions that contained black fungal stroma. Colletotrichum coccodes (Wallr.) S. J. Hughes was isolated from surface-sterilized portions of diseased stems incubated on potato dextrose agar (PDA). Cultures produced abundant black sclerotia and acervuli with setae. Acervuli produced straight and fusiform conidia (15 to 23 × 3 to 4 μm) in honey-colored masses. Ovate or long clavate appressoria were formed on slide microcultures. Pathogenicity tests were carried out in the greenhouse on soybean plants, cvs. Panda and Pony at the V4 growth stage, by (i) spraying a conidial suspension (2 ×10 conidia per ml) on seedlings and (ii) placing a mycelial PDA plug above the first two nodes of the stem, previously wounded with a sterile needle. Plain sterile water and plugs without mycelia were used as controls. Six plants per cultivar and per treatment were used. Plants were covered with polyethylene bags for 3 days. Anthracnose symptoms gradually appeared near maturity and plants senesced prematurely with both inoculation methods. Averaged over both cultivars, 100 and 50% of the plants showed symptoms when inoculated with a conidial suspension and mycelial plugs, respectively. Control plants did not have any symptoms. C. coccodes was consistently reisolated from stems, leaves, petioles, and pod peduncles with symptoms, and was not reisolated from noninoculated plants. Seeds collected from plants inoculated with either method showed infection rates up to 14 and 8% on cvs. Panda and Pony, respectively, while seeds collected from control plants showed 0% infection rate. The most common pathogen associated with soybean anthracnose is C. truncatum (Schwein.) Andrus and W. D. Moore, but other species have been reported to cause anthracnose. C. coccodes was reported on soybean in Italy (1). This pathogen has a wide host range and causes serious damage, mostly on solanaceous crops. This is the first report of the presence of the pathogen on soybean in the United States. Reference: (1) G. Conca et al. Petria 4:193, 1994.
1996年9月，在伊利诺伊州的大豆（Glycine max (L.) Merr.）品种Yale上观察到炭疽病症状。下部茎干被含有黑色真菌菌核的病斑环绕。从在马铃薯葡萄糖琼脂（PDA）上培养的病茎表面消毒部分分离出了围小丛壳菌（Colletotrichum coccodes (Wallr.) S. J. Hughes）。培养物产生了大量黑色菌核和具刚毛的分生孢子盘。分生孢子盘产生呈蜜色团块的直形和梭形分生孢子（15至23×3至4μm）。在玻片微培养上形成了卵形或长棍棒状附着胞。在温室中对处于V4生长阶段的大豆品种Panda和Pony进行了致病性测试，方法如下：（i）向幼苗喷洒分生孢子悬浮液（每毫升2×10个分生孢子），（ii）在茎的前两个节上方放置一个带有菌丝体的PDA菌块，茎预先用无菌针划伤。使用普通无菌水和无菌丝体的菌块作为对照。每个品种和每种处理使用6株植物。用聚乙烯袋覆盖植物3天。两种接种方法在接近成熟时炭疽病症状逐渐出现，植物过早衰老。两个品种的平均发病率分别为：接种分生孢子悬浮液时100%，接种菌丝体菌块时50%。对照植物没有任何症状。从有症状的茎、叶、叶柄和豆荚梗上始终能重新分离出围小丛壳菌，未接种的植物上未分离到该菌。用任一种方法接种的植物所结种子，品种Panda和Pony的感染率分别高达14%和8%，而对照植物所结种子的感染率为0%。与大豆炭疽病相关的最常见病原菌是菜豆炭疽菌（Colletotrichum truncatum (Schwein.) Andrus and W. D. Moore），但也有其他物种被报道可引起炭疽病。在意大利曾报道过围小丛壳菌侵染大豆（1）。该病原菌寄主范围广泛，造成严重危害，主要危害茄科作物。这是该病原菌在美国大豆上出现的首次报道。参考文献：（1）G. Conca等人，Petria 4:193，1994年。
