Synergistic effect of PPFD and mycorrhization for efficient in vitro propagation of Dendrobium chrysanthum wall. ex lindl.

Integration of optimal photosynthetic photon flux density (PPFD) and mycorrhization under in vitro conditions appears to have significant synergistic effect in enhancing the growth and survival of the medicinal orchid, Dendrobium chrysanthum under in vitro and ex vitro conditions. PPFD at 60 µmol m-2 s -1 was found to be optimal for root colonization for mycorrhizal association by fungi (73% colonization). The growth of mycorrhizal plantlets was observed to be superior at 60 µmol m-2 s -1 PPFD as compared to plantlets subjected to either lower or higher PPFD.