2.2. Orchid mycorrhiza fungiTwo isolates of Tulasnella deliquescens (Juel) Juel (previously knownas Epulorhiza repens (N. Bernard) R.T.Moore) isolate Da-KP-0-1 and Pv-PC-1-1 (Nontachaiyapoom et al. 2010) were used in this study. Fungalisolate Da-KP-0-1 was obtained from a root of Dendrobium anosmumLind. and fungal isolate Pv-PC-1-1 was obtained from a root ofPaphiopedilum villosum (Lindl.) Stein. They were reported to be highlyeffective in seed germination promotion of many Dendrobium orchids(Nontachaiyapoom et al. 2011; Swangmaneecharern et al. 2012). Agarpieces containing hyphae of this fungus, stored in sterile water atroom temperature at Mae Fah Luang University, Chiang Rai, were usedfor the initial fungal culture. The agar pieces were placed on potatodextrose agar (PDA) containing antibiotics (30 μg/ml oxytetracycline,30 μg/ml streptomycin, and 30 μg/ml ampicillin) at 30 °C for one week