Phytopathology. 2000 Jul;90(7):691-8. doi: 10.1094/PHYTO.2000.90.7.691.
ABSTRACT Dendryphion penicillatum and Pleospora papaveracea were isolated from blighted Papaver somniferum and Papaver bracteatum plants grown in growth chambers and the field in Beltsville, MD. The etiology of the diseases was determined, and the fungi are being investigated as potential mycoherbicides to control the narcotic opium poppy plant. P. papaveracea is known to be a highly destructive seedborne pathogen of Papaver somniferum, causing seedling blight, leaf blight, crown rot, and capsule rot. Single conidia and ascospores were isolated and cultures established from naturally infested seed and diseased foliage and pods of opium poppy from Iran, Colombia, Venezuela, Sweden, India, and the United States (Maryland and Washington). Mycelia and conidia of P. papaveracea and D. penicillatum produced on necrotic leaf tissues appear morphologically similar, and the fungi were previously considered to be anamorph and teleomorph. However, no anamorph/teleomorph connection could be established, and the fungi appear to be distinct taxa. P. papaveracea produced conidia, mature pseudothecia, and chlamydospores in vitro and on infected stems. D. penicillatum produced conidia, microsclerotia, and macronematous conidiophores. Although both fungi were pathogenic to three poppy cultivars, conidial inoculum from P. papaveracea cultures was more virulent than conidial inoculum from D. penicillatum. Eight-week-old plants became necrotic and died 8 days after inoculation with a conidial suspension of P. papaveracea at 2 x 10(5) spores per ml. Disease severity was significantly enhanced by inoculum formulations that contained corn oil, by higher conidial inoculum concentrations, and by increased wetness periods. Symptoms on plants inoculated with either pathogen included leaf and stem necrosis, stem girdling, stunting, necrotic leaf spots, and foliar and pod blight. Inoculated seedlings exhibited wire stem, damping-off, and root rot. Conidia, and less frequently pseudothecia, of P. papaveracea and conidia of D. penicillatum were produced abundantly on inoculated, necrotic foliage, pods, and seedlings. Cultures from conidia or ascospores reisolated from these tissues consistently produced fungi whose morphologies were typical of the fungus from which the inoculum was derived.
文摘 从生长在马里兰州贝尔茨维尔温室和田间的枯萎罂粟和罂粟上分离出了枝孢菌和罂粟纸层孔菌。确定了疾病的病因，并且正在研究这些真菌作为控制麻醉鸦片罂粟植物的潜在生防真菌。已知 P. papaveracea 是一种高度破坏性的种子传播病原体，可导致罂粟幼苗枯萎、叶片枯萎、冠腐和蒴果腐烂。从伊朗、哥伦比亚、委内瑞拉、瑞典、印度和美国（马里兰州和华盛顿）的受感染种子和患病叶片以及罂粟荚中分离出单个分生孢子和子囊孢子，并建立了培养物。在坏死叶片组织上产生的 P. papaveracea 和 D. penicillatum 的菌丝体和分生孢子在形态上看起来相似，并且这些真菌以前被认为是无性态和有性态。然而，无法建立无性态/有性态连接，并且这些真菌似乎是不同的分类单元。P. papaveracea 在体外和感染的茎上产生分生孢子、成熟的假囊壳和厚垣孢子。D. penicillatum 产生分生孢子、微菌核和大分生孢子梗。尽管两种真菌均对三种罂粟品种具有致病性，但来自 P. papaveracea 培养物的分生孢子接种物比来自 D. penicillatum 的分生孢子接种物更具毒力。用 2 x 10(5)个孢子/ml 的假囊壳分生孢子悬浮液接种 8 周龄的植物后，8 天内植物坏死并死亡。用玉米油、更高的分生孢子接种物浓度和更长的湿润期处理的接种物配方显著增强了疾病的严重程度。用两种病原体接种的植物的症状包括叶片和茎坏死、茎环缢、矮化、坏死叶斑以及叶片和荚果腐烂。接种的幼苗表现出线状茎、猝倒和根腐。P. papaveracea 的分生孢子和假囊壳较少见，以及 D. penicillatum 的分生孢子在接种的坏死叶片、荚果和幼苗上大量产生。从这些组织中重新分离出的分生孢子或子囊孢子的培养物始终产生与接种物来源真菌形态典型的真菌。
