Plant regeneration, by organogenesis or somatic embryogenesis, from cell cultures and in vitro plant tissue culture is the basis for biotechnology usage in plant breeding. This research aimed to evaluate somatic embryogenesis from embryogenic calli of 'Hamlin', 'Pêra', 'Natal', 'Lima Verde', and 'Westin' sweet orange cultivars related to culture medium composition as source and concentration of carbohydrates with the use of MT culture medium modified with 500mg L-1 of malt extract, supplemented with sucrose, galactose, glucose, maltose, lactose, or sorbitol at concentrations of 18, 37, 75, 110 or 150mM at 27°C. Statistical design were complete randomized, in a factorial five (cultivars) x six (carbohydrate source) x six (carbohydrate concentration in culture medium) with five replicates. The production of somatic embryos varied with the genotype, as 'Hamlin' and 'Natal' cultivars registered higher number of embryos, whereas 'Lima Verde' and 'Westin' showed lower numbers. The best carbohydrate source was maltose, followed by lactose at concentrations of 37 and 75mM. Somatic embryogenesis was not observed on culture media supplemented with galatose, glucose or sorbitol in any studied cultivar.
Citrus sinensis; plant tissue culture; embryo
