Abstract: The effect of plant hormones on the regulating direction of differentiation and organogenesis from explant were studied by using young panicIes of haploid rice. A concensration of 2 mg/l showed the results that 2, 4 -D induced callus formation, NAA induced root formation greatly, KT inhibited callus formation and organ differentiation. KT (2mg/l ) +NAA (2mg/l ) did not induce callus tissue but a great number of plantlets differentiated from explant directly. When KT/NAA=2:2, the differentiation percentage of plantlets was higher, being 76%. The tests of different concentrations of 2, 4 -D showed that the concentration of 2 or 4 mg/l induced callus formation up to 94%. Callus subculture on solid and liquid media showed when the lower concentration of 2, 4 -D (0.5-1.0mg/l ) were added with KT (0.1mg/l ), callus grew sturdy and redifferentiation was better. Albino plantlets which regenerated from haploid rice somatic explant were very few. Possibility of using calli-clones to the study of mutant and somatic genetices was discussed. With regard to the callus redifferentiation, not only kinetin is needed, but also the effect of auxin concen-tration of the induction medium is also remarkable.

Key words: regeneration, plantlets, haploid, hormone