ENRAIZAMENTO EX VITRO E ACLIMATIZAÇÃO DE PLANTAS MICROPROPAGADAS DE Tectona grandis

O enraizamento de espécies arbóreas é bastante complexo devido à maturidade dos tecidos. O objetivo deste trabalho foi avaliar o efeito de AIB no enraizamento ex vitro de brotos micropropagados a partir de plantas jovens de Tectona grandis L. em dois substratos, bem como da porção do broto para enraizamento. Foram utilizados brotos multiplicados in vitro inteiros, ou excisados ao meio (porção apical e basal), submetidos a imersão por 10 segundos em soluções contendo diferentes concentrações de AIB (0, 100, 1000, 2000, 4000 mg.L-1) e plantados em bandejas plásticas contendo vermiculita ou Plantmax® como substratos. O enraizamento ex vitro ocorreu em todos os tratamentos, inclusive na ausência de AIB. O maior número de raízes e o maior crescimento relativo do caule foram observados para os tratamentos com o uso de AIB, em ambos os substratos. O enraizamento ocorreu em 100% dos explantes de origem apical e basal, em ambos os substratos. O enraizamento ex vitro de brotos micropropagados de T. grandis é viável a partir de plantas jovens, e a taxa de multiplicação é duplicada com o seccionamento dos brotos em porções apical e basal.Palavras-chave: Teca; produção de mudas; micropropagação; condição ex vitro; porção do broto. AbstractEx vitro rooting and acclimatization of micropropagated plantlets of Tectona grandis. The rooting of tree species is very complex due to the maturation of tissues. The objective of this study was to evaluate the effect of IBA on ex vitro rooting of micropropagated shoots from juvenile plants of Tectona grandis L. into two substrates, as well as the portion of the shoot to root. Shoots multiplied in vitro were used with whole or excised shoots (apical and basal) submitted to immersion for 10 seconds in solutions of IBA (0, 100, 1000, 2000, 4000 mg.L-1) and planted in plastic trays containing vermiculite or Plantmax ® as substrates. The ex vitro rooting occurred in all treatments, even in the absence of IBA. The largest number of roots and higher relative growth of the stem were observed in all treatments with IBA in both substrates. The survival of acclimatized plantlets occurred in all treatments. Rooting occurred in 100% of explants from apical and basal origin in both substrates. The ex vitro rooting of micropropagated shoots of T. grandis is feasible from juvenile plants and the multiplication rate is duplicated when shoots are cutin apical and basal portions.Keywords: Teak; seedlings; micropropagation; ex vitro condition; portion of the shoot.The rooting of tree species is very complex due to the maturation of tissues. The objective of this study was to evaluate the effect of IBA on ex vitro rooting of micropropagated shoots from juvenile plants of Tectona grandis L. into two substrates, as well as the portion of the shoot to root. Shoots multiplied in vitro were used with whole or excised shoots (apical and basal) submitted to immersion for 10 seconds in solutions of IBA (0, 100, 1000, 2000, 4000 mg.L-1) and planted in plastic trays containing vermiculite or Plantmax ® as substrates. The ex vitro rooting occurred in all treatments, even in the absence of IBA. The largest number of roots and higher relative growth of the stem were observed in all treatments with IBA in both substrates. The survival of acclimatized plantlets occurred in all treatments. Rooting occurred in 100% of explants from apical and basal origin in both substrates. The ex vitro rooting of micropropagated shoots of T. grandis is feasible from juvenile plants and the multiplication rate is duplicated when shoots are cutin apical and basal portions