Germinação e respostas morfoanatômicas de plantas jovens de Lonchocarpus cultratus (Vell.) A. M. G. Azevedo & H. C. Lima submetidas ao alagamento e total submersão.

• Ano de defesa: 2018
• Autor(a) principal: Barbeiro, Caroline
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais; UEM; Maringá
• Palavras-chave em Português: Lonchocarpus cultratus (Vell.) A; Adaptação morfoanatômica; Áreas alagadas; Anatomia ecológica; Ciências Biológicas; Ecologia
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/4861

In flooded areas the low rates of oxygen diffusion and solubility represent the main restriction to plant community development. Through morphophysiological and anatomical adjustments, plants can reduce the damage caused by oxygen deficiency by developing adaptive strategies that together contribute to their occurrence in the environment. Therefore, the goal of this study is to analyze experimentally the adaptive strategies of Lonchocarpus cultratus tree species when subjected to flooding conditions and total submersion. Fruits of L. cultratus were collected in adjacent areas of Parana River. Seeds were submitted to two germination tests (seeds under field capacity and totally submerged seeds). For morphoanatomical analysis of younger plants seeds were sown in pots in a greenhouse and submitted to the following water treatments: control group with plants in field capacity (CT), flooded (FL) and total submersion (TS). After 30 days in a hydric treatment (DAHT), 20 plants were removed from the flooding conditions and total submersion for further evaluation, composing this post-flooding (PA) and post-submersion (PS) treatments. The morphological and anatomical evaluations were performed after 30 and 60 DAHT. The morphological evaluation consisted of weekly observations. To anatomical evaluation of subterranean system, the total diameter, marrow diameter and radial thickness of the xylem (primary and secondary xylem) were measured. To eophyll, adaxial and abaxial epidermis thickness, palisade and spongy parenchyma thickness, mesophyll thickness and limbo total thickness were also measured. Results were submitted to ANOVA at 5% significance level. The main reached results were the low germinability of seeds under total submersion; the formation of stem hypertrophied lenticels and adventitious roots in flooded plants; plant death and foliar senescence in totally submerged plants; the persistent endodermis with U-shaped thick-walled cells and low amount of medullar starch in subterranean system of FL and TS plants at 30 and 60 DAHT; the reduction of the subterranean system diameter and xylem in FL and TS plants at 60 DAHT; the reduction of the adaxial and abaxial epidermical thickness in FL and TS plants at 60 DAHT; the larger thickness of the spongy parenchyma, mesophyll, limbo and the larger specific leaf area (SLA) of TS plants at 60 DAHT and the reduced SLA of PS plants. All morphoanatomical adaptations of the seedlings indicate that L. cultratus is tolerant to the stress caused by flooding and total submersion.