Relações Hídricas e Produção de Pigmentos Fostossinteticos em Mudas de Eugenia Uniflora l. Sob Condições de Salinidade (Water Relations and Production of Pigments in Seedlings Photosynthetic Eugenia Uniflora l. Under Salinity Conditions)

Abstract

Esta pesquisa objetivou avaliar os efeitos da salinidade nas relacoes hidricas e teor de pigmentos fotossintetizantes em mudas de pitangueira. Para tanto, foi desenvolvido um experimento em casa de vegetacao do Laboratorio de Fisiologia Vegetal, pertencente ao Departamento de Biologia da UFRPE, no periodo de dezembro de 2010 a abril de 2011. O delineamento experimental utilizado foi o inteiramente casualizado com quatro tratamentos salinos: 0 (controle), 30, 60 e 90 mM de NaCl, e com cinco repeticoes por tratamento. Aos 35 e 95 DAD (dias apos diferenciacao) decorreram as analises fisiologicas. Foram mensurados o potencial hidrico foliar e o teor relativo de agua em dois horarios: antemanha (4h) e meiodia (12h) e os pigmentos fotossintetizantes. A alta demanda evaporativa (12 horas) ocasionou reducoes significativas para o potencial hidrico foliar e teor relativo de agua na pitangueira. Nestes horarios tambem ocorreram diferencas nos pigmentos, entre os niveis de salinidade estudados. Os resultados indicam que a imposicao da salinidade propiciou reducoes no status hidrico das plantas. Em relacao aos pigmentos fotossinteticos, o estresse em curto prazo gerou sua diminuicao, porem em longo prazo, gerou aumento dos mesmos. A variavel fotossintetica estudada mais afetada foram os carotenoides. Palavras-chave: Potencial Hidrico Foliar, Teor Relativo de Agua, estresse salino, pigmentos fotossinteticos Water Relations and Production of Pigments in Seedlings Photosynthetic Eugenia Uniflora l. Under Salinity Conditions ABSTRACT This research had as objective evaluate the effects of salinity in the hydric relations and photosynthetic pigments amount in Eugenia uniflora L.. A experiment was developed in the greenhouse of the Laboratory of Vegetal Phisiology, UFRPE, Brazil, between December 2010 and April 2011. The experimental was designed with four treatments: 0 (control), 30, 60 and 90 mM NaCl with five repetitions each treatment. At 35 and 95 days of experiment physiological analysis were performed. It was measured the leaf hydric potential and the relative water content, at two different moments: pre-morning, AND MID DAY and the photosynthetic pigments. The high evaporative demand (mid day) caused significant reductions in the leaf hydric potential and relative water content in the E. uniflora. At the referred times it was also possible to observe differences in the photosynthetic pigments between the levels of stressing. Results indicate that the imposition of high salinity reduced the hydric status of the subjects. Relating to the photosynthetic pigments the short-term salt stress caused a reduction that was overcome in the long-term stressing. The most affected pigment studied were the carotenoids. Keywords: Leaf hydric potential, relative water content, salt stress, photosynthetic pigments

Anatophysiology of Vouacapoua americana Aubl. in the juvenile phase: A species included in the IUCN red list of threatened species

“…In Brazil, until a few years ago, the occurrence of of such extreme weather events. However these extreme weather events are not a particularity of Brazil, being registered worldwide; the changes caused global warming, including tropical ecosystems by reducing the levels of precipitation and evapotranspiration (Marques et al, 2011).…”