RESUMEN
ABSTRACT The effects of various sucrose concentrations as carbon source and natural additives in different media on plantlet growth of Phalaenopsis hybrid 'Pink' were studied. Plantlets were cultured on two media (Murashige and Skoog [MS] and Vacin and Went [VW]) supplemented with 0, 10, 20, 30 and 40 g L-1 sucrose either with 0, 10 and 20% (v/v) coconut water (CW) or carrot juice (CJ) as natural additives. After four months of culture, the combination of sucrose and CW supplemented with both media affected plantlet growth where most of the plantlets showed slow growth and survival frequency (0-80%) with increasing concentrations of CW in all sucrose concentrations. However, plantlet growth on both media containing only 20 g L-1 sucrose without CW was optimal in terms of root number, root length, leaf number, leaf length, leaf width, fresh weight, dry weight and plant height. The combination of sucrose and CJ supplemented with MS medium resulted in overall good plantlet growth with 100% survival frequency. The combination of sucrose (20 g L-1) and CJ (10%) supplemented with MS medium increased root length, leaf length, leaf width and plant height. Plantlet growth was also optimal in the combination of 20 g L-1 sucrose and 10% CJ supplemented with VW medium. The results of this study indicate that Phalaenopsis hybrid 'Pink' cultured on the combination of sucrose (20 g L-1) and CJ (10%) supplemented with either MS or VW media can be used for plantlet growth of this species.