Embriogênese somática em mamoeiro seleção THB
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Data
2013-02-25
Autores
Detoni, Jamile Lenhaus
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Editor
Universidade Federal do Espírito Santo
Resumo
This work aimed to assess the somatic embryogenesis in juvenile explants from the
papaya tree selection THB. Apex stems and cotyledonary leaves inoculated by
induction medium (IM): MS salts, sucrose (30 g L-1), myo-inositol (100 mg L-1),
Phytagel®
(2.8 g L-1) and concentrations of 2,4-D (6; 9; 12; 15 and 18 µM) or 4-CPA
(19; 22; 25; 28 and 31 µM). After 50 days, the embryogenic calluses were transferred
to the maturation medium (MM): MS without growth regulator; ABA (0.5 µM); ABA
(0.5 µM) + CA (15 g L-1
); ABA (0.5 µM) + CA (30 g L-1
); ABA (0.5 µM) + PEG (60 g L1
) for 30 days. The data were submitted to analysis of variance by the F test and the
averages compared by the Tukey test in level of 5% and analysis of regression. In
IM, for both auxins, the responses were superior than when cotyledonary leaves
were used, except the callogenesis. For the somatic embryo types, embryos in
premature phase prevailed in both auxins, like globular and heart-shaped ones. For
the 2,4-D, it was not possible to establish a great concentration for the response, but
with the 4-CPA all the variables had their maximum level close to 25 µM. In this
concentration, it was possible to obtain 91.67% of embryogenic calluses in
cotyledonary leaves. For histological analysis of cotyledonary leaves, it was possible
to identify the somatic embryos formation from parenchyme cells, prevailing the
indirect form, but not synchronized. The occurrence of secondary somatic
embryogenesis and the formation of abnormal embryos were also identified. For the
maturation process, in the composition of the medium in which was detected a larger
occurrence of somatic embryos (70 ES calo-1
), as well as a lower percentage of
geminated ES (4%), there was ABA (0.5 µM) + CA (15 g L-1
). Therefore, for the
somatic embryogenesis of the papaya tree selection THB, it is recommended the
induction of cotyledonary leaves in 4-CPA (25 µM), being the maturation in an
medium with ABA (0.5 µM) + CA (15 g L-1
).
Descrição
Palavras-chave
Carica papaya L. , Juvenile explant , Explantes juvenis , Synthetic auxins , Auxinas sintéticas , Maturation , Maturação , Microscopic analysis , Análise microscópica
Citação
DETONI, Jamile Lenhaus. Embriogênese somática em mamoeiro seleção THB. 2013. 64 f. Dissertação (Mestrado em Agricultura Tropical) - Programa de Pós-Graduação em Agricultura Tropical, Universidade Federal do Espírito Santo, São Mateus, 2013.