Montero-Astúa M, Vásquez V, Rivera C
Centro de Investigación en Biología Celular y Molecular (CIBCM), Universidad de Costa Rica (UCR).
CIBCM and Facultad de Microbiología, UCR.
Plant Dis. 2002 Nov;86(11):1273. doi: 10.1094/PDIS.2002.86.11.1273B.
Powdery scab of potatoes, caused by Spongospora subterranea (Wallr.) Lagerheim f. sp. subterranea Tomlinson, is important worldwide due to its effect on tuber quality and transmission of Potato mop-top virus. Although powdery scab-like lesions have been observed on potato in Costa Rica (1), the presence of the pathogen has not been confirmed. During a survey in 2001, powdery scab-on was observed from a field and a greenhouse in the high elevation zone of the main potato-producing area of Costa Rica. Commercial potatoes with scab-like lesions were also obtained at a farmers' market. Scraping the lesions, and observing spore balls or cystosori with a honey-comb-like structure under light microscopy confirmed the identity of S. subterranea. The identity of the pathogen was also confirmed by enzyme-linked immunosorbent assay using monoclonal antibodies specific for S. subterranea (BioReba Ag, Reinach, Switzerland). Pathogenicity of S. subterranea was confirmed by a bioassay on tomato plants grown in nutrient solution culture (2). Tomato cv. Supermarmande plants were grown from seed in pots filled with quartz and watered with nutrient solution. Three weeks after planting, the roots were trimmed to 60 mm, and the plants were transferred to the nutrient solution for additional growth. After growing for 1 week in the nutrient solution, tomato seedlings were inoculated by replacing the nutrient solution with nutrient solution containing cystosori (20 mg/liter, wt/vol) that were scraped from the scab lesions. Zoosporangia of S. subterranea were observed in root hairs and epidermal cells of the seedlings 2 weeks after inoculation. To our knowledge, this is the first report that confirms the presence of S. subterranea on potato in Costa Rica. References: (1) R. Amador. Invest. Agri. Costa Rica. 1(1):16, 1987. (2) U. Merz. Bull. OEPP 19:585, 1989.
马铃薯粉痂病由马铃薯粉痂菌（Spongospora subterranea (Wallr.) Lagerheim f. sp. subterranea Tomlinson）引起，因其对块茎品质的影响以及马铃薯帚顶病毒的传播，在全球范围内都是一个重要问题。尽管在哥斯达黎加已观察到马铃薯上出现类似粉痂病的病斑（1），但病原菌的存在尚未得到证实。在2001年的一项调查中，在哥斯达黎加主要马铃薯产区的高海拔地区的一块田地和一个温室中发现了粉痂病。在一个农贸市场也获得了带有痂状病斑的商品马铃薯。刮去病斑，在光学显微镜下观察到孢子球或具有蜂窝状结构的包囊堆，从而确认了马铃薯粉痂菌的存在。使用针对马铃薯粉痂菌的单克隆抗体（瑞士雷纳赫市的BioReba Ag公司）通过酶联免疫吸附测定也证实了病原菌的身份。通过在营养液培养中种植的番茄植株上进行生物测定（2），证实了马铃薯粉痂菌的致病性。番茄品种Supermarmande的植株从种子开始在装满石英的花盆中生长，并用营养液浇灌。种植三周后，将根部修剪至60毫米，然后将植株转移到营养液中继续生长。在营养液中生长1周后，用含有从痂状病斑刮下的包囊堆（20毫克/升，重量/体积）的营养液替换营养液，对番茄幼苗进行接种。接种两周后，在幼苗的根毛和表皮细胞中观察到马铃薯粉痂菌的游动孢子囊。据我们所知，这是首次证实哥斯达黎加马铃薯上存在马铃薯粉痂菌的报告。参考文献：（1）R. 阿马多尔。《哥斯达黎加农业研究》。1(1):16，1987年。（2）U. 默茨。《欧洲植物保护组织通报》19:585，1989年。
