Víchová J, Vejražka K, Cholastová T, Pokorný R, Hrudová E
Mendel University, Brno, Czech Republic.
Agricultural Research Ltd., Troubsko, Czech Republic.
Plant Dis. 2011 Jan;95(1):79. doi: 10.1094/PDIS-08-10-0614.
Safflower (Carthamus tinctorius L.) is an oil crop that is suitable for dry growing conditions in the Czech Republic. Most of the Czech production is used as bird feed. Typical anthracnose symptoms were observed at one safflower field in the Moravia Region of the Czech Republic during the 2005 growing season. Since then, the disease has become widespread with 100% yield losses observed in several locations in 2009. Symptoms consisted of circular spots on leaves and stem blight characterized by dark-colored stem lesions bearing salmon-colored conidia masses in acervuli. A fungus was isolated from symptomatic safflower plants (cv. Sabina) on potato dextrose agar and incubated at 25°C as described by Kwon et al. (3). The color of fungal colonies changed from white to gray with age with salmon-orange pigmentation on the reverse side of plates. Similar observations had been reported by Jelev et al. (1). Conidia were colorless, fusiform, and measured 10 to 17 μm (mean 13.59) × 4 to 8 μm (mean 5.98). Morphology suggested a Colletotrichum sp. To fulfill Koch' postulates, safflower plants at the BBCH 12 growth stage (second leaf fully expanded) were spray inoculated with a conidia suspension (1 × 10 conidia/ml). Growth chamber conditions were temperature 20 ± 1°C, relative humidity 70 ± 5%, with a 16-h photoperiod. Control plants were treated with sterile distilled water. Typical anthracnose symptoms were observed 1 week after inoculation. Control plants were symptomless. The pathogen was reisolated from infected stems and leaves. PCR with primers CaInt2 and ITS4 was used to confirm the identification of a Colletotrichum sp. Reaction products obtained with these primers were approximately 500 bp long. The ribosomal DNA internal transcribed spacer region containing ITS1, 5.8S, and ITS2 of the isolate from safflower was sequenced and identified with the BLASTn program. The sequence matches with 100% similarity to the sequence of the Glomerella acutata teleomorph of Colletotrichum acutatum (GenBank Accession No. AB548282) and 100% similarity to C. simmondsii (GenBank Accession No. GU183359). C. acutatum and C. simmondsii can be distinguished from each other by pigment color (4), with the safflower isolate matching the description of C. simmondsii. Kim et al. (2) recorded C. acutatum on safflower fields in the Euiseong area of Korea in 1997. To our knowledge, this is the first report of C. simmondsii causing safflower anthracnose in the Czech Republic. References: (1) Z. J. Jelev et al. Plant Dis. 92:172, 2008. (2) W. G. Kim et al. Plant Pathol. J. 15:62, 1999. (3) J. H. Kwon et al. Plant Pathol. J. 15:172, 1999. (4) R. G. Shivas and Y. P. Tan. Fungal Divers. 39:111, 2009.
红花（Carthamus tinctorius L.）是一种适合在捷克共和国干旱生长条件下种植的油料作物。捷克的大部分红花产量用作鸟饲料。2005年生长季节期间，在捷克共和国摩拉维亚地区的一块红花田观察到典型的炭疽病症状。自那时以来，该病已广泛传播，2009年在几个地方观察到产量损失达100%。症状包括叶片上的圆形斑点和茎枯病，其特征是茎部病斑颜色深，在分生孢子盘上带有鲑鱼色分生孢子团。从有症状的红花植株（品种Sabina）上在马铃薯葡萄糖琼脂上分离出一种真菌，并按照权等人（3）所述在25°C下培养。真菌菌落的颜色随着时间从白色变为灰色，平板背面有鲑鱼橙色色素沉着。耶列夫等人（1）曾有过类似观察结果。分生孢子无色，梭形，大小为10至17μm（平均13.59）×4至8μm（平均5.98）。形态学表明是一种炭疽菌属真菌。为了满足柯赫氏法则，在BBCH 12生长阶段（第二片叶子完全展开）的红花植株用分生孢子悬浮液（1×10个分生孢子/毫升）进行喷雾接种。生长室条件为温度20±1°C，相对湿度70±5%，光周期为16小时。对照植株用无菌蒸馏水处理。接种1周后观察到典型的炭疽病症状。对照植株无症状。从受感染的茎和叶中重新分离出病原体。使用引物CaInt2和ITS4进行PCR以确认炭疽菌属真菌的鉴定。用这些引物获得的反应产物长度约为500 bp。对来自红花的分离物的包含ITS1、5.8S和ITS2的核糖体DNA内部转录间隔区进行测序，并用BLASTn程序进行鉴定。该序列与尖孢炭疽菌（Colletotrichum acutatum）的有性型尖孢小球腔菌（Glomerella acutata）的序列100%相似（GenBank登录号AB548282），与西蒙兹炭疽菌（C. simmondsii）的序列100%相似（GenBank登录号GU183359）。尖孢炭疽菌和西蒙兹炭疽菌可通过色素颜色区分（4），红花分离物与西蒙兹炭疽菌的描述相符。金等人（2）于1997年在韩国蔚城地区的红花田记录到尖孢炭疽菌。据我们所知，这是西蒙兹炭疽菌在捷克共和国引起红花炭疽病的首次报道。参考文献：（1）Z. J. 耶列夫等人，《植物病害》92:172，2008年。（2）W. G. 金等人，《植物病理学杂志》15:62，1999年。（3）J. H. 权等人，《植物病理学杂志》15:172，1999年。（4）R. G. 希瓦斯和Y. P. 谭，《真菌多样性》39:111，2009年。
