title: Effect of 2,4-d, hydric stress and light on indica rice (Oryza sativa) somatic embryogenesis.
abstract: With the purpose of increasing the embryogenesis regeneration process in vitroplants obtained from somatic embryos of the indica rice variety CR-5272 (Oryza sativa L.), two independent experiments were performed. The first experiment consisted in the effect of combination of three concentrations of the gelling agent Phytagel (1.8. 2.4. and 3 gL(-1)) and four 2,4-D concentrations (2.26, 4.52. 6.78, and 9.05 microM) on the induction and subsequent regeneration of embryogenic calli. On the second experiment, the pre-regeneration phase was modified: calli were subjected to darkness or diffuse light conditions for one, two, and three weeks. In embryogenesis induction, 35% calligenesis was obtained using the MS culture medium supplemented with 6.78 microM of 2.4-D and 2.4 gL(-1) Phytagel, whereas on the control treatment (MS medium supplemented with 9.05 microM of 2.4-D and 3 gL(-1) Phytagel ) 24% calligenesis was obtained. In addition, regeneration percentages were improved (22% and 16% for calli induced with the above treatments, respectively). Furthermore, in light exposure experiments, the best result was obtained by exposing the embryogenic calli to darkness for one week in pre-regeneration, followed by direct light exposure during the regeneration phase.
authors.affiliation: Centro de Investigación en Biología Celular y Molecular. Universidad de Costa Rica, San José. Costa Rica. menesesa@catie.ac.cr
authors.forename: Allan
authors.initials: A
authors.lastname: Meneses
authors.forename: Dora
authors.initials: D
authors.lastname: Flores
authors.forename: Miguel
authors.initials: M
authors.lastname: Muñoz
authors.forename: Griselda
authors.initials: G
authors.lastname: Arrieta
authors.forename: Ana M
authors.initials: AM
authors.lastname: Espinoza
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology*; D047108:Embryonic Development / Q000187:drug effects; D006540:Herbicides / Q000494:pharmacology*; D008027:Light; D012275:Oryza / Q000187:drug effects* / Q000196:embryology; D012038:Regeneration / Q000187:drug effects
chemical_list: D006540:Herbicides; D015084:2,4-Dichlorophenoxyacetic Acid