<i>In vitro</i> propagation of <i>Caesalpinia spinosa</i> (Mol.) O. Kuntz from axillary buds of selected trees

Abstract

Guarango or tara [Caesalpinia spinosa (Mol.) O. Kuntz] is a tree native to the Andes, with great economic importance and for reforestation programs. The aim of this work was to in vitro propagate this specie from axillary buds of selected trees. During in vitro establishment, the effect of sodium hypochlorite (3.0%) with different times of disinfection (5.0, 10, 15 min), as well as the effect of 6-BAP on the in vitro response of buds were studied. For multiplication, different combination of 6-BAP with 0.1 mg l-1 ANA were tested. A free-growth regulator culture medium was used for rooting. The best results for in vitro establishment were achieved with a disinfection treatment with sodium hypochlorite 3.0% for 10 minutes and cultivation in a culture medium with 0.25 mg l-1 6-BAP, which 90% of buds in vitro established, with a length of 6.71 cm. The highest multiplication rate of shoot (2.88 per explant) was obtained with 1.0 mg l-1 6-BAP and 0.1 mg l-1 ANA, after 60 days of culture. The 55% of these shoots developed roots in a half-strength basal salts MS culture medium free of regulators of growth. Keywords: biodiversity, conservation, forest plant, guarango, tissue culture