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Reis A.R.S.,Federal University of Para | de Freitas A.D.D.,Federal University of Para | Leao N.V.M.,Laboratorio Of Sementes Florestais | Filho B.G.S.,University of Amazon
Journal of Seed Science | Year: 2016

Apuleia molaris spruce ex benth, commonly known in Brazil as “amarelão,” is a fast-growing forest plant with a potential for use in reforestation; however, there is little information about the physiology and morphology of its fruits, seeds, and seedlings. Thus, the objective of this work was to describe the morphology of the fruits, seeds, and seedlings, in addition to the anatomic patterns of seedlings, as a contribution to the technical-scientific knowledge and production of amazonian species for reforestation in the state of Pará. For this purpose, the morphological descriptions followed the parameters from specialized literature and the common techniques used in plant anatomy. The species presents leguminous fruit; seeds with pleurogram, average dimensions of 51.21, 21.33, and 2.09 mm length, width, and thickness, respectively; and seedlings with eophyll and pinnate metaphylls, cordiform, phanerocotylar germination, epigaeous, and foliaceous. Eophylls and metaphylls present uniseriate epidermis, collateral and dorsiventral vascular bundle. The morphological characteristics may help in field identification and in the identification of young plants, aiding the production of seedlings of this species. Furthermore, anatomically, the hypocotyl has no striking differences from the root. Index terms: taxonomic identification, seedling production, seed technology. © 2016, Associacao Brasileira de Tecnologia de Sementes. All rights reserved.

Seeds of Schizolobium amazonicum present physical dormancy which can be broken through different scarification methods. In this work, the effects of sandpaper and hot water seed scarification on physiological aspects related to seed germination and seedling quality were evaluated. Seeds of S. amazonicum were scarified by (i) immersion in water at 100°C/2 min and (ii) by scrubbing seeds on sandpaper. Non-scarified seeds were used as control. The following variables were evaluated: tissue viability (by using tetrazolium test), germination rate, speed germination index (SGI), seed imbibition rate, endosperm depletion, and seedling emergence rate, uniformity and biomass accumulation. Seeds from both treatments were equally dyed by tetrazolium. Seeds scarified on sandpaper showed higher germination rate, higher SGI, faster seed imbibition and endosperm depletion than those scarified in water at 100°C/2 min. Seeds scarified on sandpaper presented higher seedling emergence rate and emergence index, and their seedlings were more uniform and with greater biomass than those obtained after scarification in water at 100°C/2 min. Therefore, scarification of paricá seeds on sandpaper is more efficient in promoting germination and production of uniform seedlings.

Costa M.A.,University of Amazon | Pinheiro H.A.,University of Amazon | Shimizu E.S.C.,Laboratorio Of Sementes Florestais | Fonseca F.T.,University of Amazon | And 3 more authors.
Trees - Structure and Function | Year: 2010

The effects of drought on membrane lipids and leaf pigments and the ability of andiroba (Carapa guianensis Aubl.) plants to attenuate oxidative damage through antioxidant enzymes or adjusting carotenoids and glycinebetaine (GB) were examined. Assessments were performed when pre-dawn leaf water potential (Ψpd) of water-stressed plants reached -1. 35 and -3. 21 MPa (15 and 27 days after withholding irrigation) and 12 h after resuming watering (short-term rewetting, day 28). Oxidative damages to lipids were evident on day 15, in which drought caused an increase of 47% in malondialdehyde (MDA) content. On day 27, MDA content did not differ between treatments. The activity of superoxide dismutase remained unchanged over experimental period, while significant increases in the ascorbate peroxidase (APX, 110%) and catalase (CAT, 50%) activities were observed only on day 27. GB content was 62% (day 15) and 112% (day 27) higher in water-stressed plants than in control. Regardless of Ψpd, both chlorophyll (Chl) a, Chl b and total carotenoids remained unchanged between well-watered and water-stressed plants, indicating that drought did not result in degradation of leaflet pigments. On day 28, Ψpd of water-stressed plants increased near to control plants and both activities of APX and CAT did not differ between treatments. Altogether, adjustments in APX and CAT activity and in the GB content were efficient strategies to prevent expressive oxidative damages in water-stressed andiroba plants. © Springer-Verlag 2009.

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