Symbiotic seed germination for conservation and cultivation of orchids holds colossal merit as mycorrhizal fungus in its system improves their growth and adaptability. Symbiotic activity is highly specific in some species, but in other cases the same fungus from one species is effective in a series of related species. The present work describes inter-specific activity of three fungal isolates from seedling root of Vanda thwaitesii to support seed germination and seedling growth of V. wightii, a closely related species from India. Among the three isolates, two designated as Wyd2 and Idk were identified as Ceratobasidium sp through sequencing of ITS1 and ITS4 regions. One isolate designated as Wyd1 did not clad with any described genera, but remained as an out-group under the family Ceratobasidiaceae. All the three isolates possessed binucleate hyphae producing ellipsoidal, oval or barrel shaped monilioid cells and supported 80–95% seed germination, transforming 70–85% of them into protocorms in 30 days duration. Symbiotic seedling development starting with the promeristem formation, first leaf development and second leaf initiation occurred in 95% of the protocorms in a time interval of 60 days compared to 90–120 days through asymbiotic method. The fungal isolates from Vanda thwaitesii evaluated are proved effective in V. wightii for its symbiotic seed germination and thus useful to mycorrhiza assisted conservation.