Regeneration Of Floral Organs In Vitro In Oryza Sativa.

In this study, the induction of floral organ pistil and palea/lemma from the callus was described in Oryza sativa.. For induction of floral organs, different explants—including young embryo, lemma, palea and pistil—were used for callus induction with different combinations of N~6-benzyladenine (6-BA) and 2,4-dichlorophenoxyacetic acid (2,4-D). High frequencies of callus formation from pistil and young embryo explants were achieved. Floral organs were induced after calli from pistils were transferred to medium containing both zeatin and 2,4-D. The morphological characteristics of the pistil-like organs are very similar to those formed in planta though with minor differences. Further histological study revealed that the in vitro pistil contains an ovule within its ovary. Furthermore, a pistil-specific gene, 0sMADS3 used as a molecular marker for pistil identity, was expressed in the pistil-like organs as it was in pistils in the flower of the plant. Palea/lemma-like structures in vitro are similar to Palea/lemma in planta in their morphology, however, they have different number of main veins and cell types from those in planta as indicated by morphological observation.