Name: Elizangela Rodrigues Santos
Type: MSc dissertation
Publication date: 30/07/2018
Advisor:
Name |
Role |
|---|---|
| Antelmo Ralph Falqueto | Advisor * |
| João Paulo Rodrigues Martins | Co-advisor * |
Examining board:
| Name |
Role |
|---|---|
| Antelmo Ralph Falqueto | Advisor * |
| Diolina Moura Silva | Internal Alternate * |
| Edilson Romais Schmildt | External Examiner * |
| Elisa Mitsuko Aoyama | External Alternate * |
| João Paulo Rodrigues Martins | Co advisor * |
| Luis Fernando Tavares de Menezes | Internal Examiner * |
Summary: ABSTRACT
When propagated in vitro, the explants receive all the nutrients necessary for their growth, including the carbohydrate source through the culture medium. However, it is not well understood how the carbohydrate source and concentration may affect the functionality of the photosynthetic apparatus (mainly photosystem-PSII) of these plants. The objective of this study was to evaluate the physiological and anatomical responses of Billbergia zebrina lindl. (Bromeliaceae) as a function of sources and concentrations of carbohydrates during in vitro culture. Lateral shoots of preestablished and in vitro multiplied plants were individualized and transferred to 268 ml flasks with 50 ml of MS medium containing fructose, glucose and sucrose in four concentrations (0, 15, 30 e 45 g L-1). After 55 days of cultivation, transient chlorophyll a fluorescence, anatomical leaf analysis and growth analysis were evaluated. The in vitro conditions influenced the photosynthetic and anatomical performance of plants of Billbergia zebrina. The concentration and type of carbohydrate used during in vitro culture does not diminish the performance of the photosynthetic apparatus. However concentrations above 30 g L-1 lead to morphological or anatomical modifications that show some degree of stress in plants. When grown at concentrations of 15 and 30 g L-1 independent of the carbohydrate used, the plants presented higher stomatal density. Supplementation of the culture medium with monosaccharides caused alterations in the development of xylem vessels, such as the increase in number and vessel diameter, allowing adaptation to microenvironmental conditions. The concentration range between 15 and 30 g L-1 sucrose may have a slightly greater effect as it does not lead to major changes in the performance of the photosynthetic apparatus and in the anatomy of plants.
Keywords: Anatomy bromeliads carbohydrates fluorescence.
