Organogênese de explante foliar de clones de Eucalyptus grandis x E. urophylla

Abstract

Resumo -O objetivo deste trabalho foi avaliar os efeitos dos reguladores de crescimento TDZ [1-fenil-3-(1,2,3-tiadiazol-5-il)uréia], BAP (6-benzilaminopurina) e ANA (ácido naftalenoacético) no desempenho da propagação in vitro por organogênese de explante foliar de três clones híbridos de Eucalyptus grandis x Eucalyptus urophylla. Houve resposta diferenciada dos clones quanto a intensidade, textura e coloração dos calos, em razão dos tratamentos com os reguladores de crescimento. Os melhores resultados de calejamento dos três genótipos foram observados nos tratamentos com a combinação dos reguladores de crescimento TDZ (0,5 mg L -1 ) e ANA (0,1 mg L -1 ), obtendo-se 100% de calejamento no explante foliar. Os piores resultados de calejamento foram observados nos tratamentos com a combinação dos reguladores de crescimento BAP (0,1 mg L -1 ) e ANA (0,1 mg L -1 ). Em relação à regeneração, a melhor resposta foi obtida com 1,0 mg L -1 BAP em que 8% dos calos formados a partir de explantes foliares regeneraram gemas, com número médio destas formadas por calo igual a 4,2.Termos para indexação: micropropagação, reguladores de crescimento, propagação in vitro. Organogenesis of the leaf explant of Eucalyptus grandis x E. urophylla clonesAbstract -The aim of this work was to evaluate the effects of growth regulators TDZ [1-phenil-3-(1,2,3-thiadiazol-5-yl) urea], BAP (6-benzilaminopurine) e NAA (Naphthalene acetic acid) on the in vitro propagation by organogenesis from foliar explants of Eucalyptus grandis x E. urophylla. Depending on the clone used, there were singular responses to growth regulators treatment regarding callusing intensity, texture and color. The best results of the three genotypes used were observed with the TDZ (0.5 mg L -1 ) and NAA (0.1 mg L -1 ) treatment, where 100% of the foliar explants presented callus. The worst results were observed with the BAP (0.1 mg L -1 ) and NAA (0.1 mg L -1 ) treatment. Subsequently, considering the regeneration process, the best response was achieved with 1.0 mg L -1 BAP, in which 8% of the calli regenerated buds, with an average of 4.2 buds per explant.

Plant regeneration from cotyledonary explants of Eucalyptus camaldulensis dehn and histological study of organogenesis in vitro

“…11 to 13). This confirmed the results obtained by Alves et al (2004) that indicated the adventitious origin of the buds formed in the leaf explants of the hybrid E. grandis x E. urophylla. In this case, the buds were formed on calli developed from the mesophyll of the abaxial face of the leaf after 35 d on culture medium containing 4.44 µM BAP.…”

“…The establishment and understanding of the regenerating process are essential for the success of this process. Studies on plant regeneration through organogenesis have already been reported for E. camaldulensis (Muralidharan and Mascarenhas, 1987;Mullins et al, 1997;Ho et al, 1998;Dibax et al, 2005;Quisen, 2007), E. tereticornis (Subbaiah and Minocha, 1990;Parthiban et al, 1999), E. grandis (Warrag et al, 1991;Lainé and David 1994;Hajari et al, 2006), E. urophylla (Tibok et al, 1995), E. globulus (Serrano et al 1996), E. gunnii (Hervé et al, 2001) and E. grandis x E. urophylla (Gonzales et al, 2002;Tournier et al, 2003;Alves et al, 2004). However, these mainly describe the protocol of plant regeneration and do not refer to the anatomical process.…”

Efficient Regeneration of Eucalyptus urophylla x Eucalyptus grandis from Stem Segment

“…The present results and reported in other studies together indicated that the efficiency of Eucalyptus micro-propagation was highly dependent on the adventitious bud induction. The percentage of adventitious bud formation was 91.3%, which was higher than that reported in other studies (Cid et al 1999;Hervep et al 2001;Alves et al 2004). Shoot cluster production was continuous from the calli derived from all the tested explants during the first 40 d on MS medium supplemented with 4.4 µM BA and 0.25 µM NAA.…”

Influência genotípica e clonal de genótipos de bananeiras micropropagados a partir de gemas florais masculinas

“…2) e, con-) e, consequentemente, o retorno ao estado meristemático, em processos denominados de desdiferenciação e rediferenciação, ou seja, reprogramação celular (ALVES et al, 2004).…”