Plant regeneration induced from mature embryo-derived callus of Balinese red rice (Oryza sativa Cv. Barak Cenana)

Recalcitrant regeneration is one of the bottlenecks for plant improvement, especially in monocotyledonous species. In this research, plantlet regeneration of a native rice cultivar Oryza sativa ‘Barak Cenana’, high-value local Balinese red rice was successfully demonstrated. Compact nodular calli were induced from excised seed derived mature embryos of ‘Barak Cenana’ rice. Although 2,4-D was necessary for callus induction, a combination of 2,4-D in regeneration medium caused reduction of green spot and shoot meristemoid differentiation. Root differentiation was firstly regenerated where meristematic shoots were thereafter developed from calli. The highest number of shoot regeneration regenerated from green spots and numbers of plantlet with complete shoot/root development were observed when transferred calli to Murashige and Skoog (MS) medium containing 5 mgL-1. Multiple shoot formation of regenerated plantlets revealed for efficient regeneration system, which was firstly reported in this present study and will potentially serve for plant improvement of this native rice, Barak Cenana.