Ecofisiologia de plantas jovens de Garcinia Brasiliensis Mart. (Clusiaceae) submetidas a diferentes regimes hídricos e a alta temperatura.
Fruit growing is an interesting option for the agronomic development in the Amazon. Favorable conditions for the production of various native and exotic species become an excellent option for recovery of degraded areas and income generation. However, global climate change and water stress are inc...
| Autor principal: | Gouvêa, Paula Romenya dos Santos |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
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| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/5241 http://lattes.cnpq.br/8802743882830605 |
| Resumo: |
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Fruit growing is an interesting option for the agronomic development in the Amazon.
Favorable conditions for the production of various native and exotic species become
an excellent option for recovery of degraded areas and income generation.
However, global climate change and water stress are increasingly detrimental to
productivity. This study aimed to evaluate the behavior of young plants of Garcinia
brasiliensis submitted four irrigation treatments during the initial phase of vegetative
growth, to identify morphological and physiological characteristics affected by water
stress. The study was conducted in a greenhouse at the National Institute for
Research in the Amazon Manaus-AM. Two experiments were carried out by
completely randomized design. The Experiment I with seven repetitions, starting
190 days after germination, lasting 90 days, the water levels in the soil were divided
into four treatments (100%, 75%, 50% and 25% of field capacity).The variables
analyzed were leaf water potential (Ψf), stomatal conductance (gs ), maximum
photosynthesis (Amax), transpiration (E), water use efficiency (EUA), intrinsic
efficiency in water use (EIUA), maximum quantum efficiency (Fv/ Fm), effective
quantum yield (ΦFSII), the electron transport rate (ETR) and non- photochemical
quenching (NPQ). Biochemical parameters were analyzed, including chloroplastic
pigments, carbohydrates, proline, and growth variables, such as stem height,
diameter, leaf area and dry mass allocation. Water stress led to reduced leaf area
(p ≤ 0,035). There was no statistical difference in the values of gas exchange, and
chloroplastic pigments. The effect of treatments on levels of sugar (p ≤ 0,01) and
starch content (p ≤ 0,001) were significant, and an increase of 64% in treatment
with lower water availability was observed. There was also an effect of treatments
on proline content (p = 0,05). The second experiment was carried out 90 days after
germination, lasting 15 days, we evaluated water regimes and chlorophyll
fluorescence in seedlings exposed to two temperatures 27°C and 38°C. No effect of
water regimes on fluorescence was observed (p < 0,05). The Fv/Fm ratio was
reduced by 16% in treatment exposed to 38°C compared to 27°C, indicating that the photochemical apparatus was affected by the high temperature. The values of the
effective quantum yield, the electron transport rate and non-photochemical
quenching were also affected by the high temperature exposure, but there was no
effect of the water regime on the fluorescence parameters. In all cases seedlings of
Garcinia brasiliensis showed different strategies, and managed to acclimate to the
different types of stresses imposed. |