- 期刊
金線蓮莖腐病及其病原菌
Stem Rot of Taiwan Anoectochilus and Its Causal Organism
摘要
金線蓮莖腐病(stem rot)的病原菌經分離鑑定為Fusarium oxysporum Schl.，普遍發生在金線蓮的栽培場，是本省新發現的一種重要病害。莖腐病菌之大孢子壁薄而纖細，具有足細胞。面頂細胞較細，有1-4隔膜，而其中以3個隔膜者最為普遍，大小為12.8-36.3 × 3.3-4.9μm。小孢子0-1隔膜，大小為6.2-16.2 × 2.5-5.0μm；分生孢子柄為單生瓶狀枝，長度為5-15μm(平均9.55μm)，厚膜胞子球形，表面平滑而壁厚，單一或成對著生於菌絲末端或菌絲間，直徑5-16μm；本菌最適生長之溫度24 C，最適生長之酸鹼度為pH 5-6，最適生長之水份潛勢 -10 bar。測定本茵的寄主範圍．發現其無法感染其它蘭科植物，因此推測可能係－新的分化小種。
並列摘要
Taiwan Anoectochilus (including Anoectochilus formosanus and A. Koshunensis), the native orchid species widely distributed among 800 to 1500 meters altitute mountains in Taiwan, is used as herb for medical purposes. Due to great extent of collections, it is nearly extincted from its native habitats. Recently, extensive cultivations are practiced using seedlings raised by tissue culture techniques. Stem rot is a prevailing disease of this new crop which caused considerable yield loss during the artificial cultivation. The causal fungus was identified as Fusarium oxysporum with following characteristics: Macroconidia are abundant, sickle-like shaped, thin-walled, 1-4 septa, 12.8-36.3X 3.3-4.9 μm, with an attenuated apical cell and a foot-shaped basal cell. Conidiophorcs are monophialidic, and very short 5-15 μm. Chlamydospores are present with diameter of 5-16 μm. The optimum temperature and pH for mycelial growth were 24 C and 5-6, respectively. The optimum water potential for mycelial growth and sporulation was -10 bars. The fungus was pathogenic only to A. formosanus and A. koshunensis but not to other members of orchidaceae. It is most likely that this fungus is a new forma specialis of F. oxysporum.