细极链格孢发育及其侵染铁皮石斛的显微观察

摘要

Alternaria tenuissima was a pathogen of black spot inDendrobium officinale. The development ofAlternaria tenuissima and its infection process on leaves of Dendrobium officinale were observed in this paper. The results showed that growth rate of Alternaria tenuissima was fast, infected host by wound, then it could germinate and colonize on leaves ofDendrobium officinale. Conidia ofAlternaria tenuissima germinated in 12h, hyphae forming in 24h, conidiophores producing in 3-4d of inoculation with some chain-like spores, then a large amount of hyphae and conidia were formed in 5-6d, and covering on wound tissue of host.%细极链格孢是引起铁皮石斛黑斑病的病原菌。文章观察病原菌的生长发育及其侵染铁皮石斛叶片过程。结果表明：细极链格孢发育速度较快，通过伤口侵染寄主植物，并能在叶片上萌发、生长和定殖，从而引起病害。分生孢子于12h时萌发，24h形成菌丝，第3-4d产生孢子梗，并在其上着生链状分生孢子，第5-6d时产生大量菌丝和分生孢子，并布满了整个伤口组织。