Madia M, Gaetán S
Fitopatología, Facultad de Agronomía, Universidad de Buenos Aires, Avda San Martín 4453, 1417, Buenos Aires, Argentina.
Plant Dis. 2005 Aug;89(8):911. doi: 10.1094/PD-89-0911C.
Common sage, Salvia officinalis L., is produced primarily in greenhouses for the culinary herb market in Argentina. Since 2003 during autumn and winter, powdery mildew symptoms have been repeatedly observed on potted common sage plants in commercial greenhouses located on the outskirts of Buenos Aires. The average disease incidence during this period was 85 to 90%. Circular, white, powdery patches developed on leaf surfaces and stems. Heavily infected leaves turned brown and died. Hyaline mycelium and nonlobed appressoria were observed. Conidiophores were simple with straight foot cells measuring 53.0 to 80.0 × 10.0 to 12.3 μm. Conidia were aseptate, hyaline, cylindrical to ovoid, measured 33.0 to 40.5 × 15.0 to 18.5 μm, did not contain fibrosine bodies, and were produced in chains. Cleistothecia were not observed. The pathogen was identified as Erysiphe cichoracearum DC (1). Pathogenicity was confirmed by gently pressing leaves displaying abundant sporulation onto the adaxial surface of healthy leaves. After 10 to 12 days, typical signs and symptoms of powdery mildew appeared on all inoculated plants. Pathogenicity tests were conducted in a greenhouse at 20 to 23°C and included 10 sage plants (five inoculated and five noninoculated). The experiment was performed twice, each time with the same result. Control plants did not show any signs or symptoms. E. cichoracearum DC was previously reported in the United States on Salvia sp. (2).To our knowledge, this is the first report of an outbreak of powdery mildew caused by E. cichoracearun on potted common sage plants produced in greenhouses in Argentina. References: (1) H. J. Boesewinkel. Rev. Mycol. Tome 41:493, 1977. (2) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989.
普通鼠尾草（Salvia officinalis L.）主要在温室中种植，供应阿根廷的烹饪香草市场。自2003年以来，在秋冬季节，位于布宜诺斯艾利斯郊区的商业温室中，盆栽普通鼠尾草植株上反复出现白粉病症状。在此期间，平均发病率为85%至90%。叶片表面和茎上出现圆形、白色的粉状斑块。严重感染的叶片变为褐色并死亡。观察到透明的菌丝体和无叶状附着胞。分生孢子梗简单，基部细胞直，大小为53.0至80.0×10.0至12.3μm。分生孢子无隔膜、透明、圆柱形至卵形，大小为33.0至40.5×15.0至18.5μm，不含纤维质体，呈链状产生。未观察到闭囊壳。该病原菌被鉴定为菊科白粉菌（Erysiphe cichoracearum DC）（1）。通过将大量产孢的叶片轻轻压在健康叶片的正面来确认致病性。10至12天后，所有接种的植株上均出现了典型的白粉病症状和体征。致病性试验在20至23°C的温室中进行，包括10株鼠尾草植株（5株接种，5株未接种）。该实验进行了两次，每次结果相同。对照植株未表现出任何症状和体征。菊科白粉菌（E. cichoracearum DC）此前在美国的鼠尾草属植物上有过报道（2）。据我们所知，这是阿根廷温室中盆栽普通鼠尾草植株上首次爆发由菊科白粉菌引起的白粉病的报道。参考文献：（1）H. J. Boesewinkel. Rev. Mycol. Tome 41:493, 1977. （2）D. F. Farr等人. 美国植物和植物产品上的真菌. 美国植物病理学会，明尼苏达州圣保罗，1989.
