Banca de QUALIFICAÇÃO: HIPOLYANA SIMONE DE OLIVEIRA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : HIPOLYANA SIMONE DE OLIVEIRA
DATE: 02/02/2024
TIME: 09:00
LOCAL: Plataforma de vídeo conferência Google Meet
TITLE:

Germination and recruitment of forest species in Atlantic Forest fragments

KEY WORDS:

alternating temperature, water stress and forest seeds

PAGES: 30
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitotecnia
SPECIALTY: Produção e Beneficiamento de Sementes
SUMMARY:

The ability of forest seeds to germinate in environments subject to greater solar radiation, water stress and higher temperatures is essential to guarantee forest regeneration and the establishment of seedlings in clearings and edge areas. The present study aims to evaluate seed germination and seedling establishment of species occurring in forest fragments of the northeastern Atlantic Forest. For this qualification, we present a literature review (general theoretical framework) and the results of germination experiments (first chapter of the thesis). In this chapter, specifically, we evaluate the effect of alternating temperature and water potential on seed germination of some native Atlantic Forest species occurring in fragments of the state of Alagoas. The seeds of Miconia albicans and Eschweilera ovata were collected in forest fragments in the region of the Utinga plant (Rio Largo), while Miconia cilliata and Myrcia guianensis were collected in restinga and tableland forest areas (RPPN Reserva da Bica, Japaratinga). Seeds of Myrciaria floribunda and Schinus terebinthifolius were collected in a cultivation/urban area. In germination tests, the seeds were placed in autoclaved Petri dishes on two sheets of filter paper moistened with distilled water. The seeds were subjected to two experiments: (1) constant temperature (25°C) x alternating temperature (25 to 40°C) and (2) effect of water stress on germination (Ψ = 0, -0.4, -0.8, - 1.2 MPa). Regarding the effect of temperature alternation, there was a significant decrease in germination in Miconia cilliata and Myrcia guianensis seeds; the other species did not show a significant difference in relation to the controls. The responses found suggest variation according to the study species in relation to the temperature regime, with thermal alternation reaching 40°C being able to reduce G% in some cases, or affect germination time/speed in different ways. Regarding water stress, all species differed from the control after 30 days of observation, showing practically zero germination with the reduction in Ψ. After stress relief, after 60 days of observation, the seeds of some species (Myciaria floribunda and Miconia albicans) were able to reach germination percentages equal to those of the respective controls. The resumption of germination capacity after stress relief can be an important ecological strategy for seeds to survive and colonize areas on forest edges and open environments, including restingas and areas subject to greater water deficit in the mosaic of vegetation types included in the domain of the Atlantic Forest.

COMMITTEE MEMBERS:
Presidente - 2187545 - FLAVIA DE BARROS PRADO MOURA
Interno(a) - 3145739 - JOAO LUCIANO DE ANDRADE MELO JUNIOR
Interno(a) - 2073816 - RENAN CANTALICE DE SOUZA
Externo(a) ao Programa - 1181648 - JOSE VIEIRA SILVA - UFALExterno(a) à Instituição - DIEGO FERNANDO ESCOBAR ESCOBAR - UNESP