MICROPROPAGATION OF Pinus tecunumanii/ MICROPROPAGACAO DE Pinus tecunumanii

Pinus tecunumanii is one of the most important tropical species of Pinus in Brazil. This work aimed to develop a micropropagation protocol for Pinus tecunumanii from the apical shoots of young plants grown in a greenhouse. To optimise the aseptic treatment protocol, the effect of 0.05 or 0.1% mercuric chloride in combination with 0 or 1 g [L.sup.-1] fungicide and NaOCl was evaluated. Next, the effect of 2 or 4 [mu]M BA (6-benzyl adenine) on in vitro multiplication was evaluated over three subcultures. Supplementation with 1.5 g [L.sup.-1] activated charcoal was tested for elongation. For rooting, the effects of WV5 salts (at half strength) and 20 g [L.sup.-1] sucrose were evaluated on media supplemented with 2.68 [mu]M naphthalene-acetic acid and 0.44 [mu]M BA. Aseptic treatment of explants with 0.05% mercuric chloride and sodium hypochlorite (with or without fungicide) was effective to establish 83.3% of explants in vitro. On media supplemented with 2 or 4 [mu]M BA, shoot multiplication was promoted. After the third subculture on medium supplemented with 2 [mu]M BA, 70.83% of the explants exhibited new shoots with an average of 3.7 new shoots per explant. On medium containing activated charcoal, elongation was observed in 59.76% of the explants, while on medium without activated charcoal only 33.33% elongated. Rooting was observed in 14.8% of explants on medium supplemented with WV5 salts. Keywords: shoot multiplication; elongation; rooting. Pinus tecunumanii e uma das especies tropicais mais importantes do genero Pinus no Brasil. Este trabalho teve por objetivo desenvolver um protocolo de micropropagacao para Pinus tecunumanii a partir de gemas apicais de plantas jovens mantidas em casa de vegetacao. Para a assepsia foi avaliado o efeito de 0,05 ou 0,1% de cloreto de mercurio em combinacao com 0 ou 1 g [L.sup.-1] de fungicida e NaOCl. O efeito de 2 ou 4 [mu]M BA (6-benzil adenina) foi avaliado na multiplicacao in vitro ao longo de tres subcultivos. O efeito da adicao de 1,5 g [L.sup.-1] de carvao ativado foi avaliado no meio de alongamento. Para o enraizamento, o efeito dos sais WV5 meia forca e de 20 g [L.sup.-1] de sacarose foi avaliado em meio suplementado com 2.68 [mu]M acido naftaleno acetico (ANA) e 0.44 BA. A assepsia dos explantes com 0,05% de cloreto de mercurio, hipoclorito de sodio, com ou sem fungicida foi eficiente no estabelecimento in vitro de ate 83,3% dos explantes. Em meio suplementado com 2 ou 4 [mu]M BA ocorreu multiplicacao de brotac