Banca de DEFESA: THAMIRES OLIVEIRA REIS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : THAMIRES OLIVEIRA REIS
DATE: 31/08/2021
TIME: 14:00
LOCAL: Atividade a ser desenvolvida remotamente. Link para acesso: https://meet.google.com/vsg-jamv-qee
TITLE:

"Floral Biology of Serjania Paucidentata DC (SAPINDACEAE)"

KEY WORDS:

andromonoecious, duodichogamy, nectary, floral phenofases.

PAGES: 31
BIG AREA: Ciências Biológicas
AREA: Botânica
SUMMARY:

This study describes aspects of floral biology of Serjania paucidentata DC in natural population in post-mining restoration areas of Companhia Mineradora de Bauxita Hydro, Paragominas, northeast of Pará State, Brazil. Flowering and fruiting periods were monitored monthly during one year. Floral and inflorescence biology were studied in three expeditions with 10-15 days (August/2019 to November/2019). The floral morphology and floral biology were assessed in 8 plants at least 100 m apart. Tagged flowers were observed from pre-anthesis to full senescence and/or initial fruit development, in order to characterize longevity, floral resources and attractants, petals and sepals positioning, style growth and stigmatic lobes distention. Stigma receptivity was evaluated using the rapid drop hydrogen peroxide test; nectar sugar concentration (% brix) and volume (μl) with hand–held refractometer and microcapillars, and osmophores with neutral red solution. The flowering period extended from August to December. Fruits began to develop in October, and dispersed seeds in December to February. The inflorescences are terminal racemiform thyrses with small, multi-flowered cymes, and inconspicuous (3 to 4 mm) white staminate and bisexual one day long flowers, opening no simultaneously in the same inflorescence. The staminate flowers have rudimentary gynoecium and bisexual flowers are functionally pistillate (because they have nonfunctional stamens). Flowers of both types open at about 3 am, and the flowers already show signs of senescence at around 6 pm. At the beginning of floral anthesis, the presence of nectar was verified in both floral types. The nectar was also present in flowers of two and three days old, although they are considered flowers in the senescence phase, and are no longer attractive to visiting insects. In flowers with one, two and three days, nectar volume ranged from 0.6 to 1.2 μl with the highest production on the first day, and the sugar concentration ranged from 40 to 60%. The presence of osmophores was verified mainly in the stigma (pistillate flowers) and anthers and staminodes (staminate flowers). The odor emission is stronger around 12:00 p.m, when a large number and diversity of visiting insects is observed, as bees, moths, flies, beetles, butterflies, wasps and hummingbirds. This species presents a peculiar floral display and accessible floral resources facilitating entomophily, and exhibits sexual dimorphism of the andromonoecious type but functionally monoecious, with a rare reproductive phenomenon, duodichogamy, which involves three alternating sexual phases within an individual.

BANKING MEMBERS:
Externa à Instituição - CINTHYA CRISTINA BULHÕES ARRUDA - UFPA
Presidente - 377.382.402-53 - ELY SIMONE CAJUEIRO GURGEL - MPEG
Externa à Instituição - MARLÚCIA BONIFÁCIO MARTINS - MPEG
Externa à Instituição - MÁRCIA MOTTA MAUÉS - EMBRAPA
Externo à Instituição - WILLIAM DE OLIVEIRA SABINO - ITV