A further and detail examination of the GGB yield from all of the PGR combinations were carried out and shown in Table 2. We observed that the GGBs were even initiated with the MS PGR-free medium (control). However the best PGR combination was determined, using 5.37 มิวM NAA with no cytokinin addition, yielding 7.71+/-1.23 and 5.37 +/- 1.22 GGBs per explant (proximal part), respectively.