Contribution by: F. García-Breijo, J. Reig-Armiñana & V. Calatayud

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Quercus faginea

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Common name: Portuguese Oak

Microscopic symptoms induced in controlled conditions (fumigation with ozone)

Before visible symptoms are externally evident, some alterations can be observed by microscopy (photo below): a mature leaf in toluidine blue (4 weeks in NF+40 treatment; x1000); Vacuolar content of the palisade parenchyma cells (PP) is scattered; walls are altered (arrows), intercellular spaces (IS) increase in both the palisade (PP) and spongy parenchyma (SP).

Before visible symptoms are externally evident, some alterations can be observed by microscopy (photo below): semithin section of an ozone-exposed leaf stained with toluidine blue, showing many symptoms. Palisade parenchyma is strongly affected, with cells that are deformed and have a very dense vacuolar content. Tonoplast of vacuoles is broken and cell turgidity is reduced. Sclerenchyma strands are present. Vascular bundle sheath are rather altered. Bar: 20 µm

Symptoms induced in controlled conditions (fumigation with ozone)

Fumigation of Quercus faginea with enhanced ozone levels in Open Top Chambers (OTCs) induced yellow interveinal areas. In a comparative OTC study of four Quercus species from Spain (Calatayud et al., ined.), Quercus faginea was found to be less sensitive to ozone than Q. pyrenaica and Q. robur. After two years of fumigation, visible injury was observed in relatively few leaves.

© 2011 Fundación CEAM © 2011 Copyright of the photos: their authors