Banca de QUALIFICAÇÃO: DANIELLE PEREIRA MENDONCA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : DANIELLE PEREIRA MENDONCA
DATE: 19/08/2022
TIME: 08:30
LOCAL: Sala virtual do Meet
TITLE:

Physiological and biochemical responses in oil palm seedlings biostimulated with microorganisms and submitted to water deficit.

KEY WORDS:

Keywords: Photosynthetic efficiency, promoters and seedling production.

PAGES: 45
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Microbiologia Agrícola
SUMMARY:

The oil palm (Elaeis guineenses Jacq.) among the oilseed crops, is the most productive in the world, standing out in the production of oil of high economic value. The production of seedlings requires a long period in the nursery and the water supply is essential at this stage as it is the main limiting factor in the quality of seedlings. However, there are studies that show that microbial technology (fungi and bacteria) is effective in promoting growth and mitigating the negative effects of water deficit. The study was composed of two chapters, being chapter 1 with the following hypothesis that microorganisms alter photosynthetic performance to promote the growth of oil palm seedlings. The objective of this chapter was to evaluate the biometry, biomass accumulation, gas exchange and chlorophyll a fluorescence in leaves of oil palm seedlings inoculated with microorganisms. The experiment was carried out in a greenhouse in a completely randomized design with five treatments, comprising the inoculation of four microorganisms (UFRABA01, UFRABA124, FT12, MIX of fungi) and control (without inoculation) with five replications per treatment. The inoculation of microorganisms promoted the growth of oil palm seedlings. The height, stem diameter, number of leaves, leaf area, root length and total chlorophyll increased by an average of 37%, 49%, 16%, 223%, 63% and 15%, respectively, in the inoculated seedlings in relation to the control seedlings. The dry mass of leaves, shoots, roots and totals increased by an average of 214%, 228%, 213%, 71%, respectively, in the inoculated seedlings compared to the control seedlings. Net photosynthesis, stomatal conductance and transpiration increase by an average of 62%, 25% and 22%, respectively, in inoculated seedlings in relation to control seedlings. For chapter 2 thesis as a hypothesis that the inoculation of microorganisms as a mitigator of damage to the photosynthetic apparatus caused by water deficit. The objective is to evaluate the biometry, gas exchange, water potential, lipid peroxidation and activation of antioxidant enzymes in oil palm seedlings inoculated with microorganisms and submitted to water deficit. The experiment was carried out in a greenhouse with a completely randomized design. The treatments consisted of inoculation of microorganisms (UFRAB01 and MIX of fungi) and a control (not inoculated), with five replications, in oil palm seedlings submitted to full irrigation and submitted to water deficit (-2.5 Mpa). The inoculation of UFRAB01 and MIX increased the height and diameter of the collar regardless of the water condition. The water potential decreased in all seedlings submitted to water deficit, with the greatest reduction of 75% in the control seedlings. Net photosynthesis was drastically reduced by the water deficit, but the inoculation of UFRAB01 and MIX managed to alleviate this reduction and maintained the highest averages, about 63% higher than the control. Stomatal conductance and transpiration were reduced by water deficit, however the inoculation of UFRAB01 and MIX managed to regulate these processes to increase water use efficiency by 23% and increase carboxylation by 51% compared to the control. Lipid peroxidation (MDA) was not affected by inoculation of microorganisms. Probably, some physiological mechanisms involving the regulation of stomatal opening and greater rubisco carboxylation activity may be being activated by microorganisms to sustain the greater demand of photoassimilates necessary for greater growth and to alleviate the alterations by other non-enzymatic defense systems.

BANKING MEMBERS:
Interno - 1065086 - GLEDSON LUIZ SALGADO DE CASTRO
Externo à Instituição - JOSUÉ VALENTE LIMA
Externa à Instituição - ALESSANDRA KEIKO NAKASONE ISHIDA - EMBRAPA
Externo à Instituição - FLÁVIO JOSÉ RODRIGUES CRUZ - UFRPE