Banca de DEFESA: DANIELA PERES DE SOUZA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: DANIELA PERES DE SOUZA
DATA: 24/02/2022
HORA: 08:00
LOCAL: Google Meet https://meet.google.com/hty-vppj-trh
TÍTULO:

Wheat cultivars showed different morphophysiological strategies under water stress and recovery when grown
in Cerrado soil

PALAVRAS-CHAVES:

Tolerance; Water restriction; Fluorescence induction kinects; Photosystem II

PÁGINAS: 56
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
RESUMO:

Wheat (Triticum aestivum L.) is a grassy crop with high commercial value and one of the most
consumed food in the world. In the Cerrado, this culture has become a culture exhibiting high productivity
but is subject to water deficit, one of the main abiotic stresses in agriculture worldwide, due to the dry
winter season which can affect the plant growth and grain production. This study aimed to uncover the
strategies that contribute to the recovery of wheat different wheat cultivars, Sintonia and BRS404, under
water deficit and their yield potential in Cerrado soil sample. The experiment was conducted in a
greenhouse with two irrigation regimes (with constant irrigation and water withholding imposed in the
vegetative phase - GS39) in a randomized complete block design with five replications. The chlorophyll
a, b, and total index at rehydration period, there was a high chlorophyll investment for both cultivars. The
results showed that only for the cultivar Sintonia there was a reduction in root dry mass and only for the
cultivar BRS 404 there was an increase in the dry mass of the shoot for the reason that it invested in
tillering in the water restriction condition. At the moment of rehydration, there was a high investment in
the chlorophyll a, b and total index for both cultivars due to the chloroplast avoidance movement as a
protective mechanism involved in the reduction of the amount of light energy. This rearrangement
contributed to the protection of the photosynthetic apparatus with considerable reductions in Fv/Fm,
however, without indicating damage. The initial responses of gas exchange during the irrigation
suspension period demonstrated that Sintonia had a faster stomatal response (isohydric) while BRS was
slower at this stage. The levels of starch, TSS, and RS in BRS 404 were related to the slower recovery
process (as in the results of RWC, Fv/Fm, MDA, and H2O2). In the period of maximum stress, the level of
MDA in BRS 404 was significantly higher and remained elevated until the end of the rehydration period.
On the other hand, in the cultivar Sintonia there was an increase in the rehydration period with repair
strategies, synthesis of compounds demonstrating a decline in the concentration of amino acids and
proteins. In this same period, the cultivar Sintonia recovered the RWC values faster and showed
resumption after rehydration in the Kleaf values than the cultivar BRS 404, which justifies the reduction in
the harvest index of this cultivar. These results show great potential for tolerance to water deficit for the
cultivar Sintonia, while BRS 404 plants showed slower performance in the recovery process.

MEMBROS DA BANCA:
Interno - VITOR DE LAIA NASCIMENTO (Suplente)
Externo à Instituição - TALITA OLIVEIRA ARAUJO - UFV (Suplente)
Interno - PAULO EDUARDO RIBEIRO MARCHIORI (Membro)
Externo à Instituição - GIOVANI GREIGH DE BRITO - EMBRAPA (Membro)
Presidente - EDUARDO GUSMÃO PEREIRA - UFV (Membro)