Name: DIANA GONÇALVES COSTA
Publication date: 31/10/2023
Advisor:
Name |
Role |
|---|---|
| ANDREIA BARCELOS PASSOS LIMA GONTIJO | Advisor |
Examining board:
| Name |
Role |
|---|---|
| ANDREIA BARCELOS PASSOS LIMA GONTIJO | Presidente |
| JOÃO PAULO RODRIGUES MARTINS | Examinador Externo |
| SARA DOUSSEAU ARANTES | Examinador Interno |
Summary: Studies with in vitro water deficit inducers, such as polyethylene glycol (PEG), make it possible to search for substances that alleviate the harmful effects resulting from this stress in plants, such as silicon (Si). Therefore, the objective is to evaluate morphophysiological changes in A. blanchetiana (Baker) L. B. Smith plants supplemented with Si as a buffer against moderate and severe water stress induced by PEG-6000, cultivated in vitro. The experiment was conducted in the plant tissue culture laboratory at (Ceunes-Ufes), in a completely randomized design. A. blanchetiana shoots were transferred to MS medium (Murashige and Skoog) solidified with 6 g L -1 Agar, 4 M 1-naphthaleneacetic acid (NAA), 3% sucrose and with the presence (14 M) or absence (0 M) of Si. After 45 days, the plants were transferred to new MS medium with concentrations of PEG-6000 that simulated water deficit by reducing the osmotic potential at 0 MPa (control), -4 MPa and -6 MPa considered as stress moderate and severe water, respectively, for 30 days. After this period, evaluations were carried out for anatomical characterization, chlorophyll a fluorescence, quantification of photosynthetic pigments, growth characteristics, quantification of carbohydrate and relative water content. The data were subjected to analysis of variance and Tukey test at 5% probability. The effect of silicon as a softener proved to be efficient in conditions of moderate deficit, with greater efficiency in photochemical yield and higher chlorophyll content. The starch and sucrose content under the influence of Si showed a reduction in starch degradation and a reduction in sucrose as a form of osmotic adjustment. The isolated effect of Si was demonstrated in growth with greater root dry mass and in leaf anatomy with greater thickness of the leaf epidermis, reducing transpiration. In general, the effect of Si as a softener was efficient in A. blanchetiana plants cultivated in vitro and subjected to moderate water déficit.
