GROWTH OF ‘PRATA-ANA’ BANANA’S MICROSHOOTS CLONE GORUTUBA FROM SYNTHETIC SEEDS:SUBSTRATES AND BAP CONCENTRATION

Abstract

ABSTRACT The banana crop stands out as an activity of great social and economic importance in Brazil, which occupies the fifth place in world production. Synthetic seed production is becoming promising for a micropropagation and in vitro conservation. The aim of the study was to analyze the conversion and growth of ‘Prata-anã’ banana’s microshoots clone Gorutuba from synthetic seed in MS medium and vermiculite, different substrates and concentrations of BAP (6-benzylaminopurine) associated with ANA (acetic naphthalene acid) in the constitution of its capsule were tested. The microshoots were immersed in the sodium alginate matrix (3%) and dripped in a solution of CaCl2.2H2O (100 mM) for complexation and then in KNO3 solution (100 mM) to decomplex. The experimental design was completely randomized in a 2 x 5 factorial design (substrate x BAP concentrations), containing different substrates (MS culture medium and vermiculite) and BAP concentrations (2.22, 4.44, 6.66, 8.88 and 13.32 µmol L-1) associated with NAA (naphthalene acetic acid) 0.54 µmol L-1, totaling 10 treatments, with 4 replicates, and that each replicate containing 5 seeds. The evaluations of conversion, number of leaves, leaf length, leaf height, number of roots, root length and oxidation were performed at 30 and 60 days.The use of the MS medium provided better growth results in relation to vermiculite as substrate, in which the different BAP concentrations did not differ from each other. It was found that, in MS culture medium, BAP concentrations above 8.88 µmol L-1 in the capsule composition are not indicated for microshoots growth.