Micropropagação, caracterização dos tricomas glandulares foliares e análise da composição química dos óleos essenciais de Hyptis pycnocephala Benth. (Lamiaceae)
Carregando...
Data
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
Hyptis pycnocephala Benth., is a native and endemic species of Brazil, with distribution in
the cerrados of Tocantins and Goiás, in this, it is restricted to the region of Chapada dos
Veadeiros. It is known by the traditional Kalunga community as “alecrim-do-campo”, and
is used in the treatment of respiratory diseases and gastrointestinal disorders. The species is
endangered due to deforestation and fragmentation of its natural habitat, the Cerrado. In this
context, the objectives of this work were: to develop a micropropagation protocol, to
characterize the leaf micromorphology and the essential oil components of the species. The
plant material was collected in the municipality of Cavalcante, GO. H. pycnocephala seeds
were decontaminated and used in in vitro germination tests with different concentrations of
gibberellic acid (GA3). The seedlings obtained were used to test the media for in vitro
establishment, between MS media; MS½; WPM. For multiplication, the influence of
cytokinin 6-benzylaminopurine (BAP) and different concentrations of auxin
naphthaleneacetic acid (NAA) for rooting was tested. For acclimatization, substrates with
different amounts of gully soil, commercial substrate and sand were tested. For the
micromorphological analyses, the usual techniques of plant anatomy were used. The
essential oil was extracted by hydrodistillation in a Clevenger type apparatus and the
constituents were identified by gas chromatography coupled to mass spectrometry. In vitro
germination has better results with 144.5 µM GA3. For in vitro establishment, the WPM
medium proved to be the best. For shoot multiplication, the use of 6.66 µM of BAP is
indicated and for rooting, the use of auxins is not necessary. For acclimatization, there were
no significant differences for the substrate, however, roots with less than 1 cm provided
lower performances. A morphological and histochemical diversity was observed in the
glandular trichomes present in the leaves of H. pycnocephala, both in field and
micropropagated plants. Two types have been identified: peltado and capitate. Among the
capitates, six types have been described. Different essential oil yields and chemical
composition were obtained between leaves collected in the field when compared to
micropropagated ones. Essential oils were mainly made up of monoterpenes, sesquiterpenes.
The major compounds are endo-fenchol, α-pinene and β-caryophyllene both in samples from
micropropagation and those collected in nature. Plants from in vitro cultivation showed
higher yields compared to other samples and new compounds such as Dauca-4 (11), 7-diene
and δ-3-Carene and increased levels of β-caryophyllene and endo-fenchol. These promising
results will support future research on medicinal properties and commercial applications, in
addition to contributing to the conservation of H. pycnocephala.
Descrição
Palavras-chave
Citação
CHAGA, L. T. Micropropagação, caracterização dos tricomas glandulares foliares e análise da composição química dos óleos essenciais de Hyptis pycnocephala Benth. (Lamiaceae). 2023. 87 f. Dissertação (Mestrado em Genética e Melhoramento de Plantas) - Escola de Agronomia, Universidade Federal de Goiás, Goiânia, 2023.