In vitro SEED GERMINATION AND PROPAGATION OF Thunia marshalliana Rchb. f. ON SUBSTRATA OF LOW COST OPTIONS

Thunia marshalliana is a terrestrial orchid with immense horticultural importance. Its population in natural habitat is downsized due to different anthropogenic activities. A successful attempt was made for asymbiotic immature embryo culture and in vitro regeneration of plantlets on MS liquid medium with foam, saw dust, paddy straw and sugarcane bagasse as substrata besides agar. About 95% germination was recorded on medium with foam and sugarcane bagasse containing sucrose (3%) and NAA + BA (6 +3 µM in combination). Within 21 days of culture the immature embryos formed PLBs. The highest frequency of shoot formation occurred on medium containing agar and sugarcane bagasse as substrata where as many as 15 shoot buds developed per subculture within 13-14 days followed by medium on foam. The well rooted hardened plantlets were transferred to community potting mix containing charcoal pieces, brick pieces, coconut husks, decayed wood and sand topped with chopped mosses. About 70% of the transplants survived after two months of transfer. These suitable alternatives are cheaper than agar which can reduce the production cost in plant tissue culture to a great extent.