Isolation and Identification of Mycorrhizal Fungi from Eleven Terrestrial Orchids

Abstract

Mycorrhizal fungi were isolated from eleven terrestrial orchid species, namely Calanthe rubens, Calanthe rosea, Cymbidium sinense, Cymbidium tracyanum, Goodyera procera, Ludisia discolor, Paphiopedilum concolor, P. exul, P. godefroyae, P. niveum and P. villosum. Healthy roots of orchid hosts were collected from various parts of the country. Isolation of mycorrhizal fungi from pelotons was carried out using a modification of Masuhara and Katsuya method. Identification was based on morphological characteristics. Nuclei were stained with safranin O using Bandoni’s method. Seven genera and fourteen species of mycorrhizal fungi were identified: Ceratorhiza cerealis, C. goodyerae-repentis, C. pernacatena, C. ramicola, Ceratorhiza sp., Epulorhiza calendulina, E. repens, Rhizoctonia globularis, Sistotrema sp., Trichosporiella multisporum, Tulasnella sp. Waitea circinata and two Rhizoctonia species. Nuclear staining revealed that all strains were binucleate except for W. circinata which was multinucleate. Pure cultures were maintained on PDA slant and liquid paraffin at the Culture Collection, Department of Plant Pathology, Kasetsart University.