EFFECT OF PLANT GROWTH REGULATORS ON ORGANOGENESIS IN PROTOCORM-LIKE BODY (PLBS) OF Cymbidium dayanum IN VITRO

The present study was conducted to investigate the effect of plant growth regulator on in vitro regulation of Protocom-like-bodies (PLBs) of Cymbidium dayanum without any phyto-hormone. PLBs of Cymbidium dayanum species were explanted on Modified Murashige and Skoog (Shimasaki, 1995) medium supplemented with three types of elicitors such as “Chitosan H”, Marine Sweet (N-acethyl glucosamine) and “Hyaluronic acid ” (HA) with various concentrations. New PLBs and shoots were successfully regenerated after the application of elicitor with modified MS medium. “Chitosan H” at 0.1 mg L -1 was the highest PLBs induction rate (93%) and shoots formation rate (79%) observed with medium containing “Chitosan H”at 1 mg L -1 . Medium containing “HA” at 1 mg L -1 was the high frequency of PLBs formation rate (100%) and shoots formation rate (93%) observed at medium containing 0.001 mg L -1 and 1 mg L -1 “HA”. For induction of PLBs and shoots, “Marine Sweet” at 0.1 mg L -1 was most effective for maximum PLBs formation rate (87%) and shoot formation rate (67%). A comparative study of effective “Chitosan H”, “Hyaluronic acid 9” and “Marine Sweet” found that “Hyaluronic acid” was the best plant growth regulators which enhance both PLBs and shoots formation.