IN VITRO PROPAGATION OF VACHELLIA MACRACANTHA, AN IMPORTANT SPECIES OF THE SEASONALLY DRY TROPICAL FOREST IN NORTHERN PERU

Vachellia macracantha (ex Acacia macracantha) is one of the most important tree species in the Seasonally Dry Tropical Forest (SDTR) of northern Peru. The study aims to develop an efficient callus induction and micropropagation protocol from microcuttings of adult trees of this mentioned species, distributed across the North of Peru to the South of Ecuador. Shoot and uninodal microcuttings from three to five-year-old plants were investigated respecting their vegetative propagation and rooting capacity in vitro. High levels of NAA (2.5 to 7.5 mg L-1) were most efficient for shoot elongation and axillary bud development, although the basal callus formation and defolitation occurrence was also very high. In this case, the NAA 0.02 mg L-1, BAP 0.05, and GA3 0.05 mg L-1 interaction has been produced a better multiplication rate after 30 days without both basal callus formation and defoliation. Our findings suggest that other treatments tested such as NAA-BAP, NAA-KIN and NAA-2iP interaction, not were significantly satisfactory. Rooting response and consequently shoot elongation were always better with IBA (0.5 to 2.0 mg L-1) than NAA, under the same growth regulators concentrations.