Propagação vegetativa de erva-mate (Ilex paraguariensis Saint Hilaire Aquifoliaceae)

Abstract

Erva-mate (Ilex paraguariensis) has an economical and environmental importance to the southern area of Brazil. However, there is no enough technologies of vegetative propagation, which are important to improve yield and quality. This study had as objectives to evaluate the propagation of erva-mate trees trough cuttings and to establish an ex vitro acclimatization and micro-cutting rooting protocols from embryo cultures. Vegetative propagation potential was evaluated considering shading intensity of the stock plant and origin and size of the cuttings. Cuttings were grabbed from stock plants growing under light or shade conditions and prepared in two types (one-bud and regular types). The evaluations were the percentage of lived and died cuttings, cuttings unchanged, shoot and callus growth, shoot length, rooting, leaf survival, number and length of roots and number and length of leaves in new shoots. For acclimatization and ex vitro rooting were evaluated five concentrations of indol butyric acid (IBA) (0; 250; 500; 1,000 and 2,000 ppm) and five substrates (vermiculite, sand, carbonized rice hull, commercial substrate of pinus bark, and coconut bark). The evaluations were the percentage of cuttings unchanged, callus formation, rooting and mortality, number and length of roots, micro-cutting length, fresh weight of roots, and number of leaves in new shoots. The highest cutting unchanged was gotten with cuttings from plants growing in light. Callus formation, presence of leaves and new shoot growth affected rooting. Cuttings collected from vegetative propagated plants showed higher percentage of rooting and root length. The highest rooting percentage and micro-cutting growth were found with 1,000 ppm of IBA during acclimatization period. Acclimatization and ex vitro rooting of erva-mate micro-cuttings can be done in the substrate of carbonized rice hull and commercial substrate of pinus bark.