Estabelecimento in vitro de Handroanthus impetiginosus (Mart. ex Dc.) Mattos (Bignoniaceae) e estudo da incidência de oídio (Oidium sp.) em plântulas obtidas in vitro
Nenhuma Miniatura disponível
Data
2013-04-02
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
Handroanthus impetiginosus (Mart. ex DC.) Mattos is widely distributed
woody species in Brazil. It has economic importance for its use as wood, medicinal,
ecological and ornamental tree. There is great variation in the production of fruits and
seeds over the years, many of the seeds are attacked by fungi and insects, and finally, the
remaining intact seeds lose viability very quickly. Techniques of plant tissue culture can
increase the rate of germination in woody species. The cultivation in nutrient medium
under aseptic conditions, provides great production of seedlings in reduced time and space
and at any time of year. Furthermore, in vitro propagation acts as a tool in the identification
of microorganisms, studying their relationships and interactions with the host plant at
genetic, cellular and physiological levels. The aim of this study was to establish a protocol
for in vitro propagation of H. impetiginosus developed in three steps: decontamination and
seed germination, induction of new shoots and roots. The protocol was based on direct
organogenesis using plant material from seedlings germinated in vitro. For in vitro
germination, seed surface contamination was controlled using 2 min. in 70% ethanol and
10 min. sodium hypochlorite with 2 % active chlorine. The germination rate was 99 % on
MS medium. Induction and multiplication of new shoots were carried out with the aid of
growth regulators 6 - benzylaminopurine (BAP) and naphthalene acetic acid (NAA) in
different combinations. The results showed that for explants of H. impetiginosus all the
tested amounts of BAP and NAA have the ability to regenerate shoots, callus and
adventitious roots, it is necessary to improve the regeneration protocol to obtain greater
number of new shoots. For in vitro rooting, cuttings responded positively to 6.0 mg L - 1
butyric acid (IBA), with 92 % rooting. However, the methods of decontamination of seeds
did not control fungi of the genus Oidium. In order to identify the fungus and study the
fungus - host relationship in H. impetiginosus cuts were made in vitro leaf fragments and
the anatomical structure analyzed by optical microscope and scanning electron microscope.
After the emergence of Oidium sp. on seedlings developed in vitro, methods of seeds
disease control were tested for germination using different times and concentrations of
ethanol, sodium hypochlorite, Chlorothalonil + tiophanate Methyl (systemic fungicid ) and
Neem oil assessing the incidence and severity of each disease treatment. No treatment was
effective in the control of powdery mildew, indicating the need for further studies.
However, reduction of severity was observed in seeds treated with 70 % ethanol and
sodium hypochlorite (2% active chlorine) and Neem oil immersion to 1.5 % for 10
minutes.
Descrição
Palavras-chave
Citação
MAMEDES, T. C. Estabelecimento in vitro de Handroanthus impetiginosus (Mart. ex Dc.) Mattos (Bignoniaceae) e estudo da incidência de oídio (Oidium sp.) em plântulas obtidas in vitro. 2013. 88 f. Dissertação (Mestrado em Agronomia) - Universidade Federal de Goiás, Goiânia, 2013.