Banca de QUALIFICAÇÃO: EDISON ANTONIO DE MATTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : EDISON ANTONIO DE MATTOS
DATE: 26/10/2023
TIME: 09:00
LOCAL: Sala de Seminários I do DBG
TITLE:

LIGHT STRESS AND GAS EXCHANGES IN EM Cattleya granulosa

KEY WORDS:

Orchids, conservation, irradiance, CO2 uptake

PAGES: 90
BIG AREA: Ciências Agrárias
AREA: Recursos Florestais e Engenharia Florestal
SUBÁREA: Silvicultura
SPECIALTY: Fisiologia Florestal
SUMMARY:

A Cattleya granulosa is a endangered species. To allow its reintroduction in the natural habitats, it is critical to understand its responses in terms of growth, water status and gas exchanges under different levels of illumination in the rainy and dry season. Thus, individuals were submitted to 1800, 800, and 80 μmol.m־².s־¹ for 231 days in a nursery. High illumination induced red pigmentation in the pseudobulbs and reduced growth in young pseudobulbs and leaves. At the rainy season, the relative water content remained unaltered in the roots and leaves, but it reduced in the mid pseudobulb under 1800 μmol.m־².s־¹. In the dry season, the relative water content decreased in the young leaves and in the young and old pseudobulbs. Acidity levels were higher in the dry season than the rainy season in the leaves. In the rainy season, old pseudobulbs showed high acidity under elevated illumination. In the dry season, acidity decreased according to age in the leaves and decreased as the illumination increased in the old pseudobulbs. Regarding the gas exchanges, the species exhibits a typical CAM pattern, but plants submitted to high illumination presented a narrow period of CO2 uptake during the rainy season. The results show that this species resists light stress by reducing growth, but the relative water content and the levels of acidity are maintained especially in the young leaves.

COMMITTEE MEMBERS:
Presidente - 1228866 - EDUARDO LUIZ VOIGT
Interno - 1755074 - LEONARDO DE MELO VERSIEUX
Externo ao Programa - 1605704 - SIDNEY CARLOS PRAXEDES - UFRN