Indica rice

Rice (Oryza sativa L. cultivar Pusa Basmati-1) cultures initiated from mature caryopses were used to study the pathway of morphogenesis. Histological analysis revealed almost all the stage of somatic embryogenesis. In the initial stage of development, scutellum swelled and callus was formed that contained embryogenic cells on the periphery and parenchymatous cells in the internal region. Embryogenic cells underwent a series of organised divisions and formed proembryos that further developed into globular somatic embryos with suspensor. There was no apparent vascular connection between the developing embryos and mother tissue. The embryos further developed into heart-shaped and ultimately into bipolar embryos. Fully developed somatic embryos resembled zygotic embryos with coleoptile and scutellum. Development of secondary somatic embryos from the scutellum of primary somatic embryos was also observed.

The effect of calcium chloride on callus induction and plant regeneration from cultured immature embryos of Indian barley (Hordeum vulgare L. cultivar BL-2) and seeds of indica rice (Oryza sativa L. cultivar Pusa Basmati-1) has been investigated. Murashige and Skoog's medium containing Gamborg's medium vitamins and 20.7 M, 12.47 M & 0.2 M picloram was used for callus induction, subculture and plant regeneration in barley cultures respectively. Rice callus was induced on Murashige and Skoog's medium supplemented with 11.31M 2,4-dichlorophenoxyacetic acid and subsequently regenerated on MS medium containing 2.68 M 1-naphthaleneacetic acid and 8.87 M 6-benzylaminopurine. The basal media at different stages of culture were supplemented with different levels of calcium chloride (0 to 29.9 mM). Calcium chloride was found to be essential for plant regeneration. Higher level of calcium chloride at various phases of culture prior to regeneration was beneficial for regeneration of both barley and rice cultures. The optimum requirement was same for the two plants though for both the plants this level varied with the phases of culture. Regeneration frequency up to 100% with 2-2.5 folds higher number of regenerated plantlets was achieved when calcium chloride concentration in the induction and subculture media was raised to 14.95 mM and reduced to 2.99 mM in the regeneration medium.