Effects of gibberellic acid (GA3) and activated coal on in vitro culture of Citrus limonia Osbeck x Poncirus trifoliata L. Raf. embryos

Abstract

This work utilized fruits of a single plant obtained from the cross between Citrus limonia Osb. c Poncirus trifoliata L. Raf. Seeds were removed and after excision, all the embryos, regardless their development stages, were inoculated in MS medium added with GA₃ (0.0, 0.01, 0.1 and 1.0 mg/L) and activated coal (0.0, 0.5, 1.0 and 2.0 g/L) in every possible combination. These treatments remained for 48 hours in the dark and afterwards in growth room at the temperature of 27 ± 1^oC with 16 hours lighting. After 40 days, seedlings were evaluated by the lengths of the aerial part and root system and percent of survival. The concentration of 0.1 mg/L of GA₃ interacts negatively in culture medium containing up to 2.0 g/L of activated coal. The concentration of 0.01 mg/L of GA₃ associated to activated coal concentration of 0.5 g/L to 2.0 g/L maximized the percentage of embryo survival. Embryos showed the highest length of root (4.5 cm) and shoot (2.1 cm) when cultivated in activated coal at 0.5 g/L and 2.0 g/L, respectively.