Banca de QUALIFICAÇÃO: AMANDA SOARES SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE: AMANDA SOARES SANTOS
DATA: 14/07/2021
HORA: 15:00
LOCAL: Google Meet (meet.google.com/xki-uzax-bei)
TÍTULO: Magnesium (Mg) supplementation improves drought tolerance in soybean plants
PALAVRAS-CHAVES: Glycine max; nutrition; osmotic adjustment; plant tolerance; water deficit.
PÁGINAS: 23
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Fisiologia de Plantas Cultivadas
RESUMO:

Water deficit has severely devastated the agricultural production in many areas worldwide, due several damages to growth and productivity of crops. Our working hypothesis was that magnesium (Mg) supplementation modulates plant performance under low water availability and improves drought tolerance in soybean genotypes. Plants from genotypes Bônus 8579, M8808 and TMG1180 were grown under field conditions and subjected to three treatments of water stress (control, moderate drought and severe drought) and three Mg levels [0.9 (low), 1.3 (adequate) and 1,7 cmol_c/dm³ (supplementation)]. After 28 days of water deficit imposition, the growth (leaf area, plant height, stem diameter, fresh and dry mass), osmotic potential, relative water content, leaf succulence, Mg content and photosynthetic pigments (chlorophyll a, b, total and carotenoids) were investigated. In general, the growth parameters were dramatically decreased in all analyzed genotypes, irrespective of Mg supply, and the reductions were intensified from moderate to severe stress. Under adequate Mg supply, TMG1180 seems to be the most drought tolerant soybean genotype; but Mg supplementation did not expressively improve its tolerance. On the other hand, although M8808 genotype was found to be the most sensitive to drought under adequate Mg nutrition, a surprisingly improved-growth performance under drought was reported in plants from Mg supplementation treatments as compared to Bônus 8579 and TMG1180 ones, irrespective of drought level. The enhanced growth of high Mg-treated M8808-stressed plants was attributed to low osmotic potential, increased relative water content and Mg accumulation in aerial tissues, which resulted in enhanced photosynthetic pigments and culminated in the highest relative tolerance to water stress. The results clearly demonstrate that Mg supplementation is a potential tool for alleviation of drought harmful stress in M8808 soybean plants. Our findings suggest that improved Mg-induced plant acclimation resulted from increased water content in plant tissues and strategic regulation of Mg content and photosynthetic pigments. 

MEMBROS DA BANCA:
Presidente - 1342777 - RAFAEL DE SOUZA MIRANDA
Externo ao Programa - 021.739.953-32 - RAMILOS RODRIGUES DE BRITO - UFPI
Externo à Instituição - ALAN CARLOS DA COSTA - IFG
Externo à Instituição - FABRICIO EULÁLIO LEITE CARVALHO - AGROSAVIA