2.4-Dichlorophenoxyacetic acid and sucrose in rhizogenesis maintenance and induction in cuttings of cagaita and mangabeira from cerrado

Abstract

The Cerrado has a vast diversity of fruit plant species. Among them, the cagaita and mangabeira trees stand out because of their fruits nutritional potential. They propagate through seeds, a method that generates genetically distinct plants. Thus, it would be of interest to propagate these plants through vegetative propagation techniques aiming to select superior and identical genotypes from the mother plant. Therefore, the objective was to establish a methodology for maintenance, survival, and rooting induction of Eugenia dysenterica and Hancornia speciosa var. pubescens in nutrient solution with different sucrose concentrations added with 2.4-dichlorophenoxyacetic auxin (2.4-D). In the cagaita and mangabeira tree cuttings, five sucrose concentrations were evaluated: 0, 5, 10, 15, and 20% for the first; and 0, 10, 20, 30, and 40 % for the second species. In addition to these, the control was deionized water. To the sucrose solution was added 190 g L-1 NH4NO3, Ca3ClO, K2SO 4, and 3.00 mg L -1 of 2.4-D. We also performed a second test for cagaita tree, which was evaluated different doses of 2.4-D: 0, 0.5, 1.0, 1.5, and 2.0 mg L-1; and control (deionized water). In all experiments, the completely randomized design was used. We collected data on survival, contamination, cuttings with permanent leaves, base oxidation, callus formation, and root starts. In the first cagaita tree experiment, cuttings survival was higher than 80%. In the second trial, the use of 2.4-D did not favor the survival of the cuttings, nor did it promote the formation of root starts. For mangabeira was observed survival values of 100% in all treatments evaluated, and root starts were also found in its herbaceous cuttings.