Abstract
The excised rice roots with attached scutellum were cultured simultaneously utilizing two separate media. The root base was supplied with 12.5% sucrose via scutellum, while the root tip was immersed in the inorganic nutrients of MS medium diluted 4 times. Both root and scutellum media were supplied with different concentrations of ABA and/or figaron. ABA supplied to the scutellum medium stimulated root growth only at the relatively low concentrations, while the high concentrations were inhibitory. On the other hand supplementation of ABA to the root medium drastically inhibited root growth. Although the primary root length was detectably stimulated when ABA 10-9 M was supplied to the scutellum medium, it was drastically inhibited in the case of decapitated roots cultured under the same conditions, but the fresh weight and lateral branches were detectably increased as compared with control. Also the effect of a mixture of figaron and ABA supplied to the scutellum medium (in the same concentrations which stimulated root growth when applied separately) was found to be drastically inhibitory for root growth. Furthermore the simultaneous application of figaron and ABA to scutellum and root media respectively inhibited root growth.
