Micropropagation of caçari under different nutritive culture media, antioxidants, and levels of agar and pH

Abstract

The caçari (Myrciaria dubia) is a native fruit tree from Amazon with high concentrations of vitamin C. This study aimed to adjust a culture medium that meets the nutritional needs for the in vitro development of caçari, evaluating the effect of different concentrations and nutritive culture media, antioxidant, and levels of agar and pH. Three experiments were carried out in a completely randomized design: 1 - woody plant medium (WPM), Murashige and Skoog (MS) and Juan, Antonio, Diva and Silvia medium (JADS) nutritive media with 25, 50, 75 and 100% concentrations; 2 - pH (3.7, 4.7, 5.7 and 6.7) and agar concentrations (0, 3.5, 7.0 and 10.5 g.L^-1); 3 - Antioxidants [( ascorbic acid (AA), citric acid (CA), polyvinylpyrrolidone (PVP)] and concentrations (0, 100, 200, 300 mg.L^-1) on the control of phenolic oxidation of stem segments. After collection, the explants were disinfested in a laminar flow chamber, dipping in 70% ethanol for 3 min and 1.5% sodium hypochlorite for 12 min, followed by three washes in distilled and autoclaved water. After disinfestation, the explants were inoculated in 15 × 125 mm test tubes containing 30 mL culture medium, according to each experiment and their respective treatments. After 90 days, the number and length of sprouts (cm) and the oxidation were evaluated. The best results were obtained using the WPM medium at a concentration of 100% with 7 g.L^-1 agar, and pH adjusted to 5.7. The use of antioxidants in the tested conditions did not contribute to decrease in oxidation in explants, indicating that there is no need of adding them into the culture medium.

Keywords: Camu-camu, in vitro culture, Myrciaria dubia, organogenesis