Cyrtopodium paludicolum germination with two Tulasnella isolates

ABSTRACT Symbiosis between orchid seeds and mycorrhizal fungi has been reported to be a determining factor in the success of germination and protocorm development in vitro. The aim of this study was to isolate and identify by molecular analysis the mycorrhizal fungus associated with Cyrtopodium paludicolum, and to evaluate its efficiency in facilitating seed germination and development. Germination experiments were carried out using a fungus isolated from C. paludicolum (CH01) and Epidendrum secundum (M65), which has been successfully used a number of times in symbiotic germination. The experiments were conducted in a completely randomized design with treatments of CH01, M65 as well as under asymbiotic conditions. The mycobiont CH01 was successfully isolated from Cyrtopodium paludicolum and identified as Tulasnella sp. Treatments with both fungi reached a higher germination percentage than under asymbiotic conditions, indicating no specificity in the relationship between Cyrtopodium paludicolum and the fungi. The results presented have the potential to advance research into the propagation and conservation of C. paludicolum, a native of the Cerrado biome.摘要：已有研究证实，兰科种子与菌根真菌（mycorrhizal fungi）的共生关系，是影响其体外萌发与原球茎（protocorm）发育成败的关键决定因素。本研究旨在分离并通过分子分析（molecular analysis）鉴定与沼泽卷瓣兰（Cyrtopodium paludicolum）共生的菌根真菌，并评估其促进种子萌发与发育的效能。本研究采用两株供试真菌开展萌发实验：一株为分离自C. paludicolum的菌株CH01，另一株为此前多次成功应用于兰科共生萌发的Epidendrum secundum来源菌株M65。实验采用完全随机设计，设置CH01接种、M65接种及非共生培养（asymbiotic conditions）三组处理。经分离与分子鉴定，菌株CH01分离自C. paludicolum，归类为胶膜菌属（Tulasnella sp.）待定种。两组真菌接种处理的种子萌发率均高于非共生培养组，表明C. paludicolum与该类真菌之间不存在宿主特异性关联。本研究结果可为塞拉多生物群区（Cerrado biome）本土物种C. paludicolum的繁育与保护研究提供有力支撑。