Please use this identifier to cite or link to this item: http://repositorio.ufla.br/jspui/handle/1/56715
Title: Indução de florescimento in vitro de Cattleya walkeriana
Other Titles: In vitro flowering induction of Cattleya walkeriana
Authors: Pasqual, Moacir
Reis, Michele Valquíria dos
Pasqual, Moacir
Reis, Michele Valquíria dos
Dória, Joyce
Assis, Adriane Marinho de
Faria, Ricardo Tadeu de
Keywords: Condições hídricas
Florescimento in vitro
Fotoperíodo
Luminosidade
Paclobutrazol
Temperatura
Orquídeas
Plantas - Floração
Water conditions
In vitro flowering
Photoperiod
Luminosity
Paclobutrazol
Temperature
Orchids
In vitro flowering
Issue Date: 26-Apr-2023
Publisher: Universidade Federal de Lavras
Citation: NADAL, M. C. Indução de florescimento in vitro de Cattleya walkeriana. 2023. 80 p. Tese (Doutorado em Agronomia/Fitotecnia)–Universidade Federal de Lavras, Lavras, 2023.
Abstract: Cattleya L. orchids are highly appreciated for their variety of colors, shapes, and sizes of their flowers, but they have a long juvenile period. Using mechanisms that accelerate the flowering process is desirable for the market, but knowledge of the phenomena involved in this process is incipient. In this sense, the aim of this study was to investigate the physiological and biochemical behavior of Cattleya walkeriana G. in response to environmental factors (experiment i), light quality (experiment ii), and gibberellin inhibitor (experiment iii), in inducing in vitro flowering. Plants originating from in vitro seeding were subjected to the following experimental conditions: (i) after 6 months of cultivation, they were transferred to different conditions of temperature (26°C, 24°C, 20.5°C, and 17°C), photoperiod (10, 12, 14, and 16 h), and water availability (simulated with different agar doses: 0, 2.75, 5.50, 8.25, and 11 g L-1), and evaluated after 3 months; (ii) after 12 months of in vitro cultivation, they were transferred to different colors of light (red, blue, purple (simulated by 2 reds : 1 blue), and white), provided by light-emitting diodes (LEDs), and evaluated after 6 months; and (iii) after 6 months of cultivation, they were transferred to media with different concentrations of paclobutrazol (PBZ) at concentrations of 0, 0.025, 0.05, 0.075, and 0.1 mg L-1, and evaluated after 3 months. In all three experiments, growth parameters, photosynthetic apparatus, antioxidant metabolism, and carbohydrate metabolism were analyzed. Regarding the environmental factors studied, it was observed that an average temperature of 26ºC, a photoperiod of 12 to 14 hours of light, and 0 mg L-1 of agar promote more expressive growth for the species. White lighting provided greater vegetative growth and greater accumulation of H2O2, understood as a growth signal in this condition, while purple lighting provided greater formation of chlorophylls a, b, and total, and carotenoids, as well as equivalent accumulation of total soluble sugars. However, red, blue, purple, and white LED lighting can be used without damage to the species. PBZ reduced the number of leaves and roots of the species, as well as root length. Additionally, it promoted the increase of shoot, carbon accumulation, and elevation of concentrations of superoxide dismutase, total soluble sugars, reducing sugars, and proteins. The concentration of 0.1 mg L-1 of PBZ can be used for in vitro maintenance of the species. Finally, the species was not responsive to the studied factors for in vitro flowering.
URI: http://repositorio.ufla.br/jspui/handle/1/56715
Appears in Collections:Agronomia/Fisiologia Vegetal - Doutorado (Teses)

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