Banca de QUALIFICAÇÃO: ANA ECÍDIA DE ARAÚJO BRITO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ANA ECÍDIA DE ARAÚJO BRITO
DATA : 10/02/2020
HORA: 14:00
LOCAL: Auditório do PgAGRO
TÍTULO:

EFFECT OF NITRIC OXIDE AS AN ATTENUATOR FOR COPPER TOXIDITY IN CORN (Zea mays L.) IN VEGETATIVE, REPRODUCTIVE AND GRAIN STADIUMS

PALAVRAS-CHAVES:

Poaceae. Phytotoxicity. Heavy metal.

PÁGINAS: 55
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
RESUMO:

Copper is a micronutrient with a role in the development of plants, however, in excess, it becomes phytotoxic resulting in nutritional imbalances and negative responses in biochemical and physiological parameters. Nitric oxide (NO) has been highlighted as a stimulator of the seed germination process and attenuator of abiotic stresses for many species. In this context, the objective of the work was to evaluate the effect of NO as a mitigation agent for copper toxicity in maize (Zea mays L.) in its vegetative, reproductive and grain stages. The first experiment was conducted in the EBPS laboratory (UFRA/Belém campus). The design consisted of DCR-Design completely randomized in factorial 4 x 3, with 12 treatments and 8 repetitions, totaling 96 trays containing 25 seeds per repetition. The seeds of the K9606VIP3 variety were soaked for 48 hours in Germitest paper with a solution containing sodium nitroprusside Na₂ [Fe (CN)₅ NO]2H₂O (0, 75 and 150 µM), as ON donor, sodium ferrocyanide Na₄Fe (CN)₆ (0,75 and 150 µM) as compensator and deionized water (control). Germination was negatively influenced by copper concentrations that promoted an increase in the percentage of abnormal seedlings. There was a reduction in the emergency speed coefficient and a longer average time in the treatment of 200 µM of copper. NO did not attenuate copper toxicity compared to RL. There was no interaction of the effect of NO on LAP and TL, observing the negative effect of copper with increasing concentrations. The dosage of 200 µM of copper provided a lower DMR. ON mitigated the effect of toxicity in relation to MSPA in the dosages of 100 and 200 µM of copper. The dosage of 200 µM of copper promoted an increase in proline in the roots. NO measurements promoted a decrease in this amino acid in BP. The dosage of 0 µM NO promoted a higher percentage of proline in the roots. The second experiment was conducted in a greenhouse. The corn seeds were soaked for 48 hours in Germitest paper with a solution containing sodium nitroprusside Na₂ [Fe (CN)₅ NO]2H₂O (0, 200 and 300µM), sodium ferrocyanide Na₄Fe (CN)₆ (0, 200 and 300 µM) and deionized water. The seeds were sown in buckets with 15kg of soil containing copper concentrations CuSO₄.5H₂O (0, 60 and 200 mg Kg-¹) incubated for 50 days. The design consisted of RBD - Randomized Block Design, with 12 treatments and 4 repetitions, totaling 48 plants. Biometric characteristics (height; leaf area, stem diameter; number of leaves) and chlorophyll content determinations (SPAD index) were evaluated. The chlorophyll a fluorescence and gas exchange were measured. The data were submitted to ANOVA, using the Scoott-Knott test at 5% using SISVAR. There was no effect of treatments on height, leaf area, number of leaves, observing effect only on stem diameter, in which the dosage of 60mg Kg^-1 showed an increase of 32.7% compared to control. There was no effect of treatments on the SPAD index and gas exchange, only on chlorophyll a fluorescence parameters.

MEMBROS DA BANCA:
Externo à Instituição - FLÁVIO JOSÉ RODRIGUES CRUZ - UFRPE
Externo à Instituição - LUMA CASTRO DE SOUZA - PMCP
Presidente - 1970202 - RICARDO SHIGUERU OKUMURA
Externo à Instituição - ROBERTO LISBOA CUNHA - EMBRAPA