Shoot Elongation of Phaius tankervilliae
Elongation of shoots was found to be most excellent on GA3 containing medium over other media supplemented with different hormones. Transferring the micro shoots to MS + GA3 (2.89 - 14.43 _M) produced better elongation (data not shown), with GA3 (2.89 _M) producing maximum elongation of 4.0 cm (Sathyanarayana et al. 2008). The gibberellins are concerned in several physiological process regulations such as seed germination, initiation and growth of flowers and shoot elongation (Rkhis et al. 2006 and Ben Nissan et al. 2004) observed that GA3 (gibberellic acid) has role in cell elongation in stems. At this time for shoot elongation purpose, 0.5 cm long shoots were cut and transferred to ½, ¾ and standard MS media supplemented with GA3 (0.5gm liter). In ¾ MS media, shoots were elongated up to 4 cm within eight days while in the two other concentrations of MS media (1/2 , ¾ MS), no prominent response can be achieved. There was shown to be gradual but continuous increase in the length of shoots. The elongation was shown to be solely depends on the presence of GA3 hormone because no significant shoot elongation was observed in the control jars containing ¾ MS media without GA3 supplementation..