Direct and indirect organogenesis from nodal segments, leaves and roots of Eugenia involucrata DC

Abstract

Eugenia involucrata DC. (Myrtaceae) is a tree native to Argentina, Brazil, Paraguay and Uruguay, with important economic potential. Its propagation and conservation are limited by the recalcitrant characteristic of its seeds, being tissue culture an efficient method for these purposes. In this work, the effect of explant type and different combinations of plant growth regulators, BAP, TDZ and ANA on adventitious shoot formation, rooting and seedling formation of E. involucrata were evaluated. Three experiments were developed, induction, shoot differentiation and greenhouse seedling acclimatization. BAP and TDZ hormones induced callus and shoots from nodal, root and leaf segments. The maximum percentage of shoot formation by direct organogenesis was obtained in nodal segments grown on MS ½ medium with 2.25 mg/L BAP and the maximum frequency of callus formation was obtained in nodal or root explants grown on MS ½ medium supplemented with TDZ, alone or combined with ANA. Maximum adventitious shoot formation, by indirect organogenesis, was obtained in nodal segments, induced on MS ½ medium supplemented with 1.1 mg/l TDZ+0.93 mg/l ANA and subcultured on MS ½ medium with 0.5 mg/l TDZ+1 g/l activated charcoal. Shoot apices obtained from direct and indirect organogenesis rooted in vitro on PGRs-free MS ½ medium, forming seedlings that were then acclimatized in greenhouses, showing a high survival rate six months after transplanting.