Department of Plant Physiology, College of Basic Sciences and Humanities, G.B. Pant University of Agriculture and Technology, Pantnagar-263 145, Uttaranchal.
Mature embryos of rice (Oryza sativa L. cv Pusa Basmati I) were cultured on agar nutrient media containing 2 mgl−1 2,4-D and 30 gl−1 sucrose. An opaque, yellowish white, compact and well-organized callus tissue was formed by the proliferation of scutellar cells. Globular somatic embryos arose from single cells of the scutellar epithelium on the surface of the proliferating callus in three weeks. These globular structure showed distinct bipolarity even at early stage of development and developed directly into well organized somatic embryos. Embryos passed through globular, heart and torpedo stages which grew to cotyledonary stage for plantlet formation. Histological studies confirmed all the three stages of somatic embryos. On the contrary, studies in other mono cots have shown that somatic embryos proceed through globular, coleoptiles and scutellar stages and that there is no involvement of heart shape stage of the embryo.
Callus, plant regeneration, rice and somatic embryogenesis
