A Two-Step Approach to Scale Up Green Plant Regeneration Through Somatic Embryogenesis from in vitro Cultured Immature Inflorescences of a Male Sterile Line and a Maintainer Line of Rice

Abstract

ABSTRACT A novel, two-step protocol for rapid propagation of cyto-plasmic male sterile (CMS: A line) and maintainer (B line) line of rice through somatic embryogenesis was developed and more than 100-170 green plantlets from A and B lines were regenerated per single immature inflorescence after 8 weeks of culture. Immature inflorescence explants of IR58025A and IR58025B were cultured on an induction medium supplemented with 2 mg l−1 2,4-dichlorophenoxy acetic acid (2,4-D) and 0.5 mg l−1 6-benzyl amino purine (BAP) for a period of 2 weeks. The medium under appropriate conditions of explant age and hormones allowed predetermination of partially differentiated cells of the individual spikelet into an embryogenically competent proembryogenic group. Differentiation of these proembryogenic groups was achieved by transferring them to embryo proliferation medium containing a high concentration of BAP, proline and maltose for a period of 2 weeks. About 800-1200 green plants could be regenerated after 8 weeks of cu...