Title : In vitro establishment of Colt cherry rootstock from two vegetative tissues
Abstract:
The establishment stage in the micropropagation of fruit plants is limited by the high presence of bacteria and fungi in mother plants, which systemically colonize the explants and invade the in vitro culture medium. This represents one of the most difficult problems to control in in vitro plant culture; especially woody species. This study evaluated the effect of three disinfection treatments on explants: T1 (3% NaDCC), T2 (1.25% sodium hypochlorite + 96º ethanol), and T3 (2 g/L sulfur + 10% PPM), aiming to achieve successful in vitro establishment. Contamination and phenolization (tissue oxidation) were assessed in two types of explants: (i) nodal segments and (ii) meristematic buds, under the three disinfection treatments, along with immersion in an antioxidant solution to control phenolization in disinfected explants. Contamination in the explants began to appear on the second day, while phenolization was observed from the fifth day onward. A completely randomized experimental design was employed, applying ANOVA and Tukey test for comparing means at 5%. Significant differences among treatments were found after 35 days of in vitro establishment. Treatments T1 and T2 showed no significant differences in the disinfection of either nodal segments or meristematic buds, achieving between 50% and 52.3% aseptic cultures. The best treatment obtained was T3 for the disinfection of meristematic buds, achieving 80% aseptic cultures and a low phenolization rate of 10%, when the meristematic buds were immersed in an antioxidant solution composed of citric acid and ascorbic acid, both at a concentration of 0.25 g/L for 20 minutes.
