Bobev S G, Castlebury L A, Rossman A Y
Agricultural University, Plovdiv, Bulgaria.
Systematic Mycology and Microbiology Laboratory, USDA-ARS, Beltsville, MD 20705.
Plant Dis. 2008 Jan;92(1):173. doi: 10.1094/PDIS-92-1-0173A.
In the winter of 2007, severe damage was observed on numerous indoor potted plants of Dracaena sanderiana hort. Sander ex Mast. ("lucky bamboo") in Plovdiv, Bulgaria, which were imported from a country of unknown origin. These plants were already in the retail distribution stream. Initially, the internodes of infected stems appeared pale green with yellowish lesions. An upward spreading necrosis led to a weakness of the stems with wilt and death of the plants occurring within 2 weeks. Eventually, entire stems were covered with numerous, black, globose-to-ellipsoid acervuli with sparse, black setae. The fungus was aseptically isolated from stem lesions on potato dextrose agar (PDA) on which it produced fast-growing, pale pink colonies. On the plant and in culture, the conidia were hyaline, broadly clavate to cylindrical, occasionally slightly curved, and measured 20 to 34 × 6.7 to 10.0 μm (average 28 × 8.5 μm). On the basis of the symptoms on the plant and morphological, cultural, and molecular characteristics, the fungus was identified as Colletotrichum dracaenophilum D.F. Farr & M.E. Palm (1). Pathogenicity of the fungus was confirmed by artificial inoculation of healthy plants of D. sanderiana (three replicates). Stems were inoculated by inserting small mycelial plugs from 7-day-old PDA cultures into wounds that were subsequently covered with Parafilm strips. After 2 weeks, pale green lesions started developing on all inoculated plants and the fungus was successfully reisolated. No symptoms were found around the pure agar control wounds. The specimen from Bulgaria was deposited in the U.S. National Fungus Collections (BPI 877337) with the derived culture deposited as CBS 121453. In addition, the internal transcribed spacer region of the nrDNA of this isolate was sequenced and deposited as GenBank Accession No. EU003533. To our knowledge, this is the first report of C. dracaenophilum on potted plants outside of China and is the first report of this species in Bulgaria. Reference: (1) D. F. Farr et al. Mycol. Res. 110:1395, 2006.
2007年冬季，在保加利亚普罗夫迪夫，人们观察到许多从来源不明国家进口的室内盆栽富贵竹（Dracaena sanderiana hort. Sander ex Mast.）受到严重损害。这些植物已进入零售分销渠道。最初，受感染茎的节间呈现淡绿色并带有淡黄色病斑。坏死向上蔓延，导致茎部柔弱，植株在两周内枯萎死亡。最终，整个茎上布满了许多黑色的、球形至椭圆形的分生孢子盘，并有稀疏的黑色刚毛。该真菌从茎部病斑上无菌分离到马铃薯葡萄糖琼脂（PDA）上，在其上形成生长迅速的淡粉色菌落。在植株上和培养物中，分生孢子透明，宽棍棒形至圆柱形，偶尔略弯曲，大小为20至34×6.7至10.0μm（平均28×8.5μm）。根据植株上的症状以及形态、培养和分子特征，该真菌被鉴定为嗜龙血炭疽菌（Colletotrichum dracaenophilum D.F. Farr & M.E. Palm）（1）。通过对健康富贵竹植株进行人工接种（三个重复），证实了该真菌的致病性。通过将7日龄PDA培养物中的小菌丝块插入伤口，随后用Parafilm条覆盖来对接种茎。两周后，所有接种植株上开始出现淡绿色病斑，并且成功地再次分离到了该真菌。在纯琼脂对照伤口周围未发现症状。来自保加利亚的标本保存在美国国家真菌收藏中心（BPI 877337），衍生培养物保藏为CBS 121453。此外，对该分离株nrDNA的内部转录间隔区进行了测序，并作为GenBank登录号EU003533保存。据我们所知，这是嗜龙血炭疽菌在中国境外盆栽植物上的首次报道，也是该物种在保加利亚的首次报道。参考文献：（1）D.F. Farr等人，《真菌研究》110:1395，2006年。
