RESPOSTA FISIOLÓGICA DE PLANTAS DE MAMOEIRO SUBMETIDAS AO DÉFICIT HÍDRICO

No Brasil, em especial no Norte, o mamoeiro tem sido tradicionalmente cultivado em condições de agricultura de sequeiro, sujeita aos elevados riscos causados pelas variações do clima. Objetivando-se avaliar o efeito do estresse hídrico sobre conteúdo relativo de água nas folhas e nos teores de sacarose, carboidratos, prolina e glicina-betaína nas folhas e raízes de mamoeiro (Carica papaya L), conduziu-se um experimento em casa de vegetação em delineamento experimental inteiramente casualizado, com dois tratamentos (irrigado (controle) e déficit hídrico), com 28 unidades experimentais, no qual cada unidade foi composta de uma planta/vaso. Os efeitos provocados pelo déficit hídrico, em plantas de mamoeiro, foi à redução do o conteúdo hídrico nas folhas e aumento nos teores de sacarose, carboidratos solúveis totais, prolina e glicina-betaína, tanto nas raízes quanto nas folhas

GERMINAÇÃO DE SEMENTES E MORFOLOGIA DE Jacaranda copaia (AUBL.) D. DON.

Seed germination represents the initial stage for the future establishment of the species, supporting seed technology. The objective of this work was to describe the morphology of fruits and seeds, evaluate technological aspects and the germination of Jacaranda copaia. The fruits were collected in the experimental field of the Federal Technological Institute of Pará-IFPA, municipality of Altamira-PA. The methodology and terminology used were adjusted to the conventional techniques of plant morphology, which are illustrated by photographs. The temperature and substrate were also evaluated for seed germination. The fruit is dehiscent, simple, capsule type and dry, winged seeds, light, soft texture, transparent light brown tones, elliptical format. In the germination tests, it was verified that there were no statistically significant differences and germination of the epidermal type of fanerocotonium was registered.Keywords: Amazon; biometry; seedling; parapará.A germinação de sementes representa a etapa inicial para o estabelecimento futuro da espécie, dando suporte para a tecnologia de sementes. O objetivo do trabalho foi descrever a morfologia dos frutos e sementes, avaliar aspectos tecnológicos e a germinação de Jacaranda copaia. Os frutos foram coletados no campo experimental do Instituto Tecnológico Federal do Pará-IFPA, município de Altamira-PA. A metodologia e a terminologia empregada foram de acordo com as técnicas convencionais de morfologia vegetal, sendo ilustradas por fotos. Foi avaliado ainda temperatura e substrato para a germinação de sementes. O fruto é deiscente, simples, tipo cápsula e seco, as sementes aladas, leves, de textura lisa, tons castanho-claro transparente, formato elíptico. Nos testes de germinação constatou-se que não houve diferenças significativas estatisticamente e a germinação foi registrada do tipo epígea fanerocotiledonar.Palavras-chave: Amazônia, biometria, plântula, Parapará

Negative interference on growth and morpho-anatomical modifications in young Parkia gigantocarpa plants under waterlogging

Abstract The aim of this study was to investigate the responses linked to growth and morphological and anatomical changes in young plants of Parkia gigantocarpa subjected to waterlogging conditions. The experimental design was completely randomized with two water conditions (control and waterlogging) combined with five evaluation times (0, 4, 8, 12 and 16-days waterlogging conditions). The parameters evaluated were leaf specific hydraulic conductance, plant height, stem diameter, numbers of leaf and leaflets, as well as shoot dry matter, root dry matter, and total dry matter. The data were subjected to an analysis of variance, and significant differences between the means were determined using the F-test at a probability level of 5 %. Additionally, transversal sections linked to primary and secondary roots were described. The segments from the primary root (removed from region located 4 cm below of the soil surface) and the secondary root (removed from region located 4 cm from the root apex) were fixed, stained and mounted, and subsequently photo-documented. The waterlogging provoked reduction in leaf specific hydraulic conductance, as well as negative interferences on growth. Anatomically, this stress induced the appearance of hypertrophic lenticels in base of the stem, adventitious root and formation of schizogenous aerenchyma located in cortical parenchyma of the secondary root. Therefore, these results reveal the susceptibility of young Parkia gigantocarpa plants subjected to waterlogging conditions