Name: Romário de Oliveira Silva Júnior
Type: MSc dissertation
Publication date: 13/02/2020
Advisor:
Name |
Role |
|---|---|
| Diolina Moura Silva | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Alexandre Martins Costa Santos | External Alternate * |
| Diolina Moura Silva | Advisor * |
| Elias Terra Werner | Internal Alternate * |
| Paulo Cezar Cavatte | Internal Examiner * |
| Wagner Luiz Araujo | External Examiner * |
Summary: ABSTRACT
This work aimed to evaluate the physiological performance, in the field, of two cultivars
of Mangifera indica L. (Palmer and Rosa) produced on substrates containing 0%,
20% and 50% of mining tailings. During field cultivation, no longer under the direct
influence of mining waste, the plants were subjected to two organomineral fertilization
treatments, dividing the crop into unfertilized and fertilized plants. The physiological
responses were obtained in different experimental periods: 30, 150 and 300 days from
the beginning of fertilization (DAF). The levels of leaf pigments, the kinetics of
chlorophyll a fluorescence, the levels of non-structural carbohydrates and the activity of
enzymes in the anti-oxidant system were analyzed. The results showed that the
production of seedlings with mining tailings did not change the concentration of
chlorophylls and carotenoids, but direct relationships were found with organomineral
fertilization. On the other hand, chlorophyll a fluorescence analyzes at 30DAF showed
lower photochemical performance in both cultivars that had a higher concentration of
tailings in the substrate, during the seedling phase. The OJIP curves and the JIP test
showed damage linked to photosystem II. There was less performance of photosystem II
(PIABS) due to the drop in electron flow and electron transport performance (ΨE0 and
φE0). In plants fertilized with the organomineral product, the best photochemical
performance was clear. There was greater absorption and energy capture (ABS / RC and
TR0 / RC), greater efficiency and efficiency in electron transport (ΨE0 and φE0) and in
the performance index that represents electron transport to the final FSI acceptors
(PITOTAL). At 150 and 300 DAF, the OJIP curves and the JIP test showed a different
picture than what was observed at 30 DAF. The plants of the cultivars Palmer and Rosa
showed a photochemical 'stability', however the fertilized plants showed recovery in
less time. The results obtained by the analysis of chlorophyll a fluorescence also
allowed to observe a better photochemical performance in cv. Rosa. There was no
difference in the levels of non-structural carbohydrates in both cultivars or in the
different treatments. Similar to the results obtained in the fluorescence kinetics of
chlorophyll a, at 30 DAF the enzymes catalase, ascorbate peroxidase and gauiacol
peroxidase had greater activity while at 150 and 300 DAF these enzymes had less
activity. Finally, it is concluded that organomineral fertilization, in fact, promoted
greater physiological recovery in less time, in addition to promoting better physiological
performance for mango plants.
Keywords: Post-stress; Physiological recovery; Photochemical performance.
