In Vitro Culture of Immature Peach Embryos

Embryo culture of peach and nectarine in an improvement program for development of early maturation cultivars is an indispensable process. This study aimed to evaluate the effect of BAP and GA3 on the in vitro immature embryo development of peach and nectarine. Seeds from mature peach and nectarine fruits, obtained by natural crossing of ‘Aurora 1’, ‘Tropical’, ‘Rubrosol’ and ‘Centenária’ cultivars, were removed and treated for five minutes in ethanol (70%), followed by sodium hypochlorite (20%) for 20 minutes and then washed 3 times with distilled and autoclaved water. The ovules were inoculated in 250 mL bottles, containing 50 mL of Wood Plant Medium culture medium, with 150% of the original concentration, modified at the GA3 (0; 0.1; and 1 mg.L-1) and BAP (0; 0.2; 0.4; and 0.8 mg.L-1) concentrations in all possible combinations. The experiment was a completely randomized block design in a 4 x 3 x 4 factorial, with four replications, each consisting of 4 seeds in a test tube. The data were subject to ANOVA and qualitative data means were compared with Tukey’s test at P = 0.05 of probability.  The quantitative data were compared using polynomial regression.  After 60 and 90 days, the plantlets were harvested and the average length of the aerial part (CPA), number of leaves (NF), average length of the root system (CSR) and average weight of the total fresh mass (PMFT) were recorded. The best in vitro development of the plantlets of peach and nectarine was obtained with the use of 1 mg.L^-1 of GA₃ combined with 0.5 to 0.8 mg.L^-1 of BAP.