Yun H Y, Kim Y H, James T Y
Systematic Mycology and Microbiology Laboratory, USDA-ARS, Beltsville, MD 20705.
Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Korea.
Plant Dis. 2011 Mar;95(3):358. doi: 10.1094/PDIS-09-10-0697.
Kudzu (Pueraria montana var. lobata (Willd.) Maesen & S. Almeida) is a weedy, fabaceous vine that is native to and widely distributed in Asia where it is used for various medicinal purposes such as treating convulsions and fever (2). In the United States, especially the southeastern states, kudzu has become a problematic invasive species that overgrows nearly every substrate on which it occurs. Thus, biological control strategies for controlling this vine are of great interest (4). From October to November 2004, a disease of kudzu was observed in Gwangju and Pyeongtaek in Gyeonggi Province, Korea. The disease appeared on leaves and stems as numerous, discrete, small galls, which enlarged, becoming yellowish orange and eventually erupting into orange, pulverulent sori. Galls were scattered or gregarious, amphigenous, predominately hypophyllous, and sometimes formed along veins as well as on petioles and stems. Sori that formed from galls were solitary but sometimes became confluent, 0.1 to 1 mm in diameter, globose to subglobose, and orange to dark orange; walls were hyaline and thin. Sporangia were copious in sori, typically polyhedral due to compression or globose, 16 to 32 μm in diameter, with smooth, hyaline walls and orange contents. Zoospores were not observed during several failed attempts to germinate sporangia. On the basis of morphological descriptions and keys (3), the fungus was identified as Synchytrium minutum (Pat.) Gäum. (Chytridiomycota), the only species of Synchytrium known to occur on Pueraria (1,3). Comparison with specimens from China and New Guinea (BPI 794733 and BPI 1109528) confirmed this identification. Portions of the nLSU and nSSU rDNA from one of the two Korean specimens deposited as voucher material in the U.S. National Fungus Collections (BPI 880898 and BPI 880899) were sequenced (GenBank Accession Nos. HQ324138 and HQ324139), and a subsequent BLAST search against GenBank confirmed placement in the genus Synchytrium with 95% similarity to S. decipiens. S. minutum is widespread in Asia and Oceania and also has been reported from California (1,3). To our knowledge, this is the first report of S. minutum in Korea (1) and is noteworthy to those interested in biological control of kudzu because S. minutum may have potential in this regard. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , September, 2010. (2) H. S. Jung. M.S. thesis. Seoul National University, Seoul, Korea, 1997. (3) J. S. Karling. Synchytrium. Academic Press Inc., New York, NY, 1964. (4) M. A. Weaver et al. Biol. Control 50:150, 2009.
葛藤（Pueraria montana var. lobata (Willd.) Maesen & S. Almeida）是一种蔓生的豆科藤本植物，原产于亚洲并在亚洲广泛分布，在亚洲它被用于多种药用目的，如治疗惊厥和发烧（2）。在美国，尤其是东南部各州，葛藤已成为一种有问题的入侵物种，几乎在其所生长的每一种基质上都过度生长。因此，控制这种藤本植物的生物防治策略备受关注（4）。2004年10月至11月，在韩国京畿道的光州和平泽观察到葛藤的一种病害。该病在叶片和茎上表现为大量离散的小瘤，这些小瘤会增大，变成黄橙色，最终破裂形成橙色粉状的孢子堆。瘤分散或聚集，两面生，主要生于叶背面，有时也沿叶脉以及叶柄和茎上形成。由瘤形成的孢子堆单个存在，但有时会融合，直径0.1至1毫米，球形至近球形，橙色至深橙色；壁透明且薄。孢子堆中有大量孢子囊，通常因挤压呈多面体状或球形，直径16至32微米，壁光滑、透明且内含橙色物质。在几次使孢子囊萌发的尝试失败过程中未观察到游动孢子。根据形态学描述和检索表（3）将该真菌鉴定为微小集壶菌（Synchytrium minutum (Pat.) Gäum.）（壶菌门），这是已知在葛属植物上出现的唯一一种集壶菌（1,3）。与来自中国和新几内亚的标本（BPI 794733和BPI 1109528）比较证实了这一鉴定。对存放在美国国家真菌收藏馆（BPI 880898和BPI 880899）作为凭证材料的两份韩国标本之一的部分nLSU和nSSU rDNA进行了测序（GenBank登录号HQ324138和HQ324139），随后在GenBank上进行的BLAST搜索证实其归属于集壶菌属，与欺骗集壶菌（S. decipiens）相似度为95%。微小集壶菌在亚洲和大洋洲广泛分布，在加利福尼亚也有报道（（1,3）。据我们所知，这是微小集壶菌在韩国的首次报道（1），对于那些对葛藤生物防治感兴趣的人来说值得关注，因为微小集壶菌在这方面可能具有潜力。参考文献：（1）D. F. Farr和A. Y. Rossman。真菌数据库。系统真菌学与微生物学实验室，从http://nt.ars-grin.gov/fungaldatabases/获取，2010年9月。（2）H. S. Jung。硕士论文。韩国首尔国立大学，首尔，1997年。（3）J. S. Karling。集壶菌属。学术出版社，纽约，纽约，1964年。（4）M. A. Weaver等人。生物防治50:150，2009年。
