Morfoanatomia de órgãos vegetativos de plantas juvenis de Aegiphila sellowiana Cham. (Lamiaceae) submetidas ao alagamento do substrato

Abstract

ABSTRACT(Morpho-anatomy of vegetative organs in seedlings of Aegiphila sellowiana Cham. (Lamiaceae) subject to flooding). In order to uncover the morpho-anatomical responses of tree species to hypoxia, we studied the effects of flooding on vegetative organs of Aegiphila sellowiana. Young individuals were kept in drained and flooded soil for 50 and 80 days. Under flooding, there was a mortality rate of 40%. The surviving plants produced peridermic fissures, superficial roots and hypertrophied lenticels. Secondary roots of flooded plants presented greater diameter, thicker cortex, greater diameter of the cortical cells, larger intercellular spaces, and thinner vessel elements and vascular tissues. In the main roots under secondary growth and hypocotyls, cork and phelloderm became thicker under flooding. Leaves of flooded plants presented thicker midrib, larger mesophyll, higher number of trichomes and smaller stomata. Considering that part of the plants subject to flooding have died, it is possible to suggest that A. sellowiana is intolerant of soil inundation. However, the surviving plants showed morpho-anatomical modifications that could have conferred some tolerance to them. Thus, the differential tolerance observed among individuals of A. sellowiana indicates a variability of genotypes in the samples used in this study.

MORPHOANATOMY OF Garcinia madruno (KUNTH) HAMMEL (CLUSIACEAE) UNDER WATERLOGGED CONDITIONS

“…The thick, waxy cuticle provided greater protection in this study because the waterlogged plants exhibited lower water potential (Medri et al., 2011). Metcalfe and Chalk (1950) identified distinct types of vascular structures in petioles of Clusiaceae, where the vascular bundles of Garcinia mangostana L. were completely closed tubes surrounded by collateral bundles; however, it was observed that the bundles in the petiole of Garcinia madruno have a semicircular cylindrical shape.…”

Does silicon and salicylic acid contribute in the morphophysiology of Schinus terebinthifolia seedlings under flooding?

“…seedlings after 15 days of flooding, similar to what was observed for S. terebinthifolia seedlings. The reduction in number of leaves under flooding as a response to the increase in ethylene in the leaf tissue, promoting leaf abscission (Medri et al, 2011). As for chlorophyll indices, flooding had little influence, but the foliar application of 1.0 and 3.0 mM of Si and SA, respectively, favored the maintained synthesis of photosynthetic pigments.…”

Regímenes de riego y dosis de polímero hidroretenedor sobre características morfológicas y fisiológicas de plantas de Cordia trichotoma

“…Las raíces de las plantas producidas con exceso de humedad reducen la capacidad de las mismas de realizar intercambios gaseosos y de absorber agua y nutrientes, una vez que la planta reduce la transpiración y, consecuentemente, el metabolismo es perjudicado, habiendo reducción de su crecimiento (Medri et al 2011).…”

“…De acuerdo con Medri et al (2011), plantas sometidas al exceso de humedad presentan reducción en la tasa de crecimiento relativo, en función de la caída en la tasa fotosintética, con la consecuente reducción en la producción de fotoasimilados.…”