Banca de DEFESA: MARIA CAROLINA SARTO FERNANDES RODRIGUES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARIA CAROLINA SARTO FERNANDES RODRIGUES
DATE: 30/08/2023
TIME: 14:00
LOCAL: Auditório da Pós-graduação - UFRA/Belém
TITLE:

RHIZOBACTERIA AND FERTIACTYL GZ® INCREASE TOLERANCE TO WATER DEFICIT AND IMPROVE REHYDRATION OF AÇAI PALM SEEDLINGS

KEY WORDS:

Euterpe oleracea Mart., Biostimulants, Tolerance, Dry, Water recovery.

PAGES: 62
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Microbiologia Agrícola
SUMMARY:

The açaí palm (Euterpe oleracea Mart.), native to South America, is considered a palm tree of great economic importance in the Amazon region. The high sensitivity to water deficit limits the production of seedlings and hinders the expansion of commercial plantations. Biostimulants can be used as an efficient strategy to reduce seedling losses, as they increase tolerance to the negative effects of water deficit (DH) and help plants recover after rehydration. The objective of the study was to evaluate the effect of the biostimulants Bacillus subtilis (BS) and Fertiactyl GZ® (BC) on changes in gas exchange, oxidative stress and accumulation of osmoregulators caused by water deficit and to analyze the capacity of biostimulated seedlings in water recovery after a period of water deficit. The experiment took place in the greenhouse of the soil building of the Universidade Federal Rural da Amazônia-UFRA, in Belém, Pará. The study was divided into two chapters, the first one referring to the imposition of water deficit with 4 treatments and 6 repetitions. The treatments consisted of non-inoculated plants (control) and inoculated with BS, BC and BS + BC, which were evaluated under full irrigation conditions and after 7 and 14 days of water suspension. At 7 days of water deficit, the seedlings biostimulated with BC increased, respectively, 76%, 100%, 39% and 75% to A, gs, E and A/Ci. At 14 days of water deficit, plants with BC and BS+BC increased by 71% and 35% to A; 100% and 63% on gas; 75% and 25% to A/Ci and with BC, 64% to E, in relation to the control. At 14 days of water suspension, Ψw was 24% and 35% higher in seedlings biostimulated with BS and BC, compared to non-biostimulated ones. The proline content was higher in biostimulated seedlings, being more expressive in plants with BS, 75% higher than the control. At 14 days of DH, the MDA content of the control plants was statistically higher than all averages of the biostimulated plants. The highest enzymatic activity of SOD and CAT was found for BC and BS+BC and of the APX enzyme for the BS+BC treatment. The objective of the second chapter was to evaluate the photosynthetic and physiological performance of açaí seedlings after rehydration and was composed of 5 treatments and 6 replications. The treatments were BS, BC, BS + BC and non-biostimulated plants (DH control and IRR control), which were evaluated in water recovery condition at 0, 7 and 14 days of rehydration. At 7 days of rehydration, compared to the DH control, all biostimulated plants had statistically higher means of A and A/Ci. Plants with BC increased 101% A and 100% A/Ci. When compared to the IRR control, all treatments showed statistically lower means of A, gs, E and A/Ci. At 14 days of rehydration, plants inoculated with BC and BS+BC presented, respectively, 20.2% and 25.3% higher A; 29.4% and 35.3% higher A/Ci compared to control in HD. Compared to the IRR control, biostimulated plants showed statistically the same average of A and A/Ci. Açaí seedlings biostimulated with BS, BC and BS+BC accumulated more proline than control plants DH and IRR, at 0 and 14 days of rehydration. At 14 days of water deficit, the levels of MDA in control plants increased by 20.3% in relation to plants with BC. The BS+BC treatment showed higher activity for the SOD, CAT and APX enzymes in 49.6%, 160% and 75.5% higher than the DH control, respectively. The application of BC and BS+BC can be an efficient alternative to reduce the losses of açaí seedlings in non-irrigated nurseries or located in regions with defined periods of water restriction and can contribute to increase the availability of seedlings for the field that are more tolerant to the deficit. water.

BANKING MEMBERS:
Presidente - 1065086 - GLEDSON LUIZ SALGADO DE CASTRO
Externo ao Programa - 071.193.302-25 - WALTER VELLASCO DUARTE SILVESTRE - UFRA
Externo à Instituição - KADSON EMMANUEL FRUTUOSO SILVA
Externo à Instituição - FLÁVIO JOSÉ RODRIGUES CRUZ