Morphoanatomical aspects of adventitious rooting and the establishment of an efficient vegetative propagation protocol for Mimosa ophthalmocentra
摘要
Mimosa ophthalmocentra is a native species of the Caatinga with high ecological and economic potential, particularly valued for its timber uses and suitability for the restoration of degraded areas. Although seed propagation is efficient, vegetative propagation offers advantages for multiplying superior genotypes and standardizing desirable traits. This study evaluated the effectiveness of the mini-cutting technique as a vegetative propagation method for the species, considering the effect of indole-3-butyric acid (IBA) and the position of the mini-cuttings (apical and basal) on rooting, as well as investigating the temporal dynamics and anatomical features of the rhizogenic process. The experiment was conducted in a completely randomized design in a 2 × 4 factorial scheme, using four IBA concentrations (0, 2000, 4000, and 6000 mg L⁻1). Rooting dynamics were monitored for 25 days, with morphological assessments every five days, and morphoanatomical analyses performed on histological sections stained with Alcian Blue and Safranin. Basal mini-cuttings exhibited higher rooting percentage and vigor, whereas apical mini-cuttings showed greater survival, particularly under intermediate IBA concentrations. Rooting occurred via direct rhizogenesis, originating from the vascular cambium, without prior callus formation. The results demonstrate the high rhizogenic competence of the species, even in the absence of exogenous regulators, and highlight the potential of the mini-cutting technique for large-scale vegetative propagation of M. ophthalmocentra, contributing to its domestication and commercial production.