GERMINATION AND INITIAL GROWTH OF Sesbania punicea (Cav.)Benth.: INFLUENCE OF SALINITY, FLOODING AND LIGHT1

Abstract

Sesbania punicea (Cav.) Benth. has been recommended for the recovery of degraded areas. This study aimed at verifying the effect of salinity in the germination of S. punicea seeds in different hydric and luminosity conditions and assessing the influence of salinity and flooding on the growth and concentration of photosynthetic pigments. After the morphometric measurements of the fruits and seeds, we performed germination tests in different salt concentrations (0,5, 10 and 15gL-1 NaCl), keeping the seeds in a humid substrate (normoxy) or submerged (flooding), in the presence or absence of luminosity. There was a decrease in the percentage of germination and germination speed index (GSI) of seeds that were kept submerged in the dark. The average germination time (AGT) decreased up to the concentration of 10gL-1NaCl when the seeds were submitted to submersion in the presence of light. The growth and the production of leaves of seedlings exposed to flooding decreased as the salt concentration increased. The concentrations of photosynthetic pigments of seedlings of S. punicea did not differ among the treatments. Therefore, the colonization and occupation of new degraded areas by S. punicea may be limited by the presence of salts concentrations in the soil.

FATORES EDÁFICOS E HÍDRICOS LIGADOS À GERMINAÇÃO E AO DESENVOLVIMENTO INICIAL DA ESPÉCIE SUPERDOMINANTE Sesbania virgata (CAV.) PERS

“…Em contrapartida, a saturação hídrica do solo restringiria a quantidade de oxigênio e, em pouco tempo, pode gerar um ambiente hipóxico ou mesmo anóxico (Barreto et al, 2018). A respeito desse comportamento, existem trabalhos que mostram sua capacidade de ser tolerante à permanência em solos inundados, por longos períodos (Zanandrea et al, 2010), desenvolvendo estruturas morfo-anatômicas (Alves et al, 2013) ou até mesmo, mantendo suas taxas de crescimento mais elevadas do que em plantas em condições de solos drenados (Davanso-Fabro et al, 1998;Kreuzwieser et al, 2009).…”