Banca de DEFESA: VANESSA LEAO PELEJA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : VANESSA LEAO PELEJA
DATE: 28/02/2023
TIME: 15:00
LOCAL: Auditório do NTB - meet.google.com/geh-jqkn-ruh
TITLE:

RESPONSES OF Carapa guianensis AUBL. TO PHOSPHATE FERTILIZATION: GROWTH, CARBOHYDRATE DISTRIBUTION AND INTERACTION WITH ARBUSCULAR MYCORRHIZAL FUNGI

KEY WORDS:

Carbohydrates; Phosphorus; Growth; Arbuscular Mycorrhizal Fungi, suggars

PAGES: 90
BIG AREA: Outra
AREA: Ciências Ambientais
SUMMARY:

Variability in the amount of rainfall, the duration of rainless periods, and the availability of nutrients represent the most important constraints to plant growth in different regions. Experimental investigations have shown that some plants remobilize their carbohydrate reserves to release energy and form mutualistic associations with microorganisms to help mitigate stresses in different ways. Phosphorus is one of the most abundant macronutrients in plant tissues and participates in processes such as photosynthesis and respiration. It is usually poorly available in acidic and highly weathered soils, predominant in tropical and subtropical regions, which impairs plant development. In this context, the general objective of the work was to analyze the effect of phosphorus on growth, distribution of carbohydrates, concentration of ammonium and nitrate and root colonization by arbuscular mycorrhizal fungi in plants of Carapa guianensis Aubl. For this, seedlings of C. guianensis fertilized with simple superphosphate (0, 50, 250 kg ha^-1) were used. Evaluations were made during the dry and rainy seasons (at 240, 300, 360 and 420 days after planting), quantifying dry matter production, phosphorus content, distribution of total soluble sugars, reducing sugars, sucrose and starch, relative and absolute growth rate, total leaf area, density of spores in the soil and rate of root colonization by arbuscular mycorrhizal fungi, ammonium and nitrate concentration. The analyzed variables presented differences among treatments and according to each collection period (p < 0.05). At the end of the experiment, the P content of the plants did not differ among treatments. The control showed the highest mean total dry matter, total leaf area and growth rates. The distribution of carbohydrates was more influenced by environmental conditions (water), when compared to phosphate fertilization. During the dry season, an accumulation of carbohydrates by the plants and low dry matter production occurred. The average concentration of ammonium and nitrate in the roots of the control were the highest, as well as the density and colonization by mycorrhizal fungi. Increasing phosphorus levels in the soil decreased spore density and mycorrhizal colonization rates in the roots. Overall, the addition of P did not stimulate the growth and carbohydrate production of Carapa guianensis seedlings in the first year of planting when compared to the control.

COMMITTEE MEMBERS:
Presidente - 1794276 - JOSE MAURO SOUSA DE MOURA
Interno - 1776327 - THIAGO ALMEIDA VIEIRA
Interna - ***.720.282-** - LUCIETA GUERREIRO MARTORANO - EMBRAPA
Externo à Instituição - MARCIEL JOSÉ FERREIRA - UFAM
Externo à Instituição - RAIMUNDO COSME DE OLIVEIRA JUNIOR - EMBRAPA
Externo à Instituição - TOMAS FERREIRA DOMINGUES - USP
Externo à Instituição - VESPASIANO BORGES DE PAIVA NETO - UNIVASF