Banca de DEFESA: JEFFERSON DE SALES DIODATO
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.STUDENT : JEFFERSON DE SALES DIODATO
DATE: 31/03/2025
TIME: 14:30
LOCAL: Google Meet
TITLE:
KEY WORDS:
Starch; invertases; sucrose
PAGES: 70
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:
Intercropping systems are widely used in agricultural production in the state of Ceará. Favorable interactions between the planted crops determine the system’s output and can be evaluated not only in terms of yield but also in relation to the plants' physiology and biochemistry. Based on this premise, the objective was to quantify soluble, structural, and reserve carbohydrates, as well as analyze the activity of certain enzymes involved in sucrose metabolism, to assess the effects of crops in intercropping systems and determine their performance in semi-arid environments. The experiment was conducted at the field of the Center for Agricultural Sciences and Biodiversity at the Federal University of Cariri. The area was divided into plots for monoculture and intercropping of cowpea and forage grasses. The forage grasses used were tanzânia grass (Megathyrsus maximus (Jacq.) B. K. Simon & S. W. L. Jacobs cv. Tanzânia), brizantha grass (Urochloa brizantha (Hochst. ex A. Rich. cv Piatã) R. D. Webster cv. Piatã), forage sorghum (Sorghum bicolor L. Moench cv. CSF20), and maize for grain and forage (Zea mays L. cv. BRS 2022). Mature leaf samples were collected at 30, 60, and 90 days after the experiment installation. The levels of glucose, fructose, reducing sugars, sucrose, starch, and cellulose were analyzed, and the enzymatic activities of acid and neutral invertases were determined. Regarding monosaccharides and reducing sugars, no significant changes were observed in any of the systems. However, sucrose levels increased in Brizantha grass and maize in intercropping with cowpea. Starch values were higher in the cowpea/Brizantha and cowpea/sorghum intercropping systems. Cellulose levels were higher in cowpea intercropped with maize and sorghum after 60 days. The neutral invertase activity was more intense in the cowpea/tanzânia consortium, with peaks at 30 and 60 days for cowpea and at 60 and 90 days for tanzânia grass. The consortium between cowpea/Brizantha and cowpea/Tanzânia demonstrated the best acid invertase activity, with a marked increase observed in the cowpea consortium at 60 and 90 days, followed by an elevation in enzyme activity in the grass at 90 days, further highlighting the positive impact of the consortium on the enzyme's activity. The joint analysis (PCA) of the data showed that glucose accumulation was the main component (37.3%), followed by acid invertase activity (26.1%), cellulose (13.8%), and starch (8.98%). The glucose and starch accumulation variables were associated, indicating a favorable interaction on photosynthesis, especially in the cowpea/Brizantha consortium. On the other hand, an association between acid invertase activity and cellulose content could be understood as strengthening the cell wall, as observed mainly in the cowpea/tanzânia consortium. It is concluded that the cowpea/Brizantha consortium can be seen as a promising alternative system to the cowpea/maize consortium for semi-arid regions of Ceará. However, further studies are needed to complement the data and develop new applications for field practices.
COMMITTEE MEMBERS:
Interno - FRANCISCO NASCIMENTO PEREIRA JUNIOR
Presidente - JUAN CARLOS ALVAREZ PIZARRO
Externo à Instituição - SÉRGIO LUIZ FERREIRA DA SILVA - UFRPE
Externa à Instituição - YEDDA MARIA LOBO SOARES DE MATTOS - URCA