Caractérisation de la résistance au froid de deux espèces sclérophylles méditerranéennes par la fluorescence de la chlorophylle

Frost resistance characterisation of two mediterranean sclerophyllous species by chlorophyll fluorescence. Frost resistance of the photosynthetic system of 2 sclerophyllous species of the mediterranean region, Quercus ilex and Quercus coccifera, has been analysed. Measurements were made on 1 year and 1 month old leaves by the chlorophyll fluorescence induction method. Photosynthetic activity is inhibited very quickly for both the 2 species at the development stages studied. The photosynthetic system of Q ilex seems to be the most resistant but is destroyed after half an hour of exposure to cold at -20 °C, without any recovery after treatment. The effect of winter temperatures on the distribution areas of Q ilex and Q coccifera is discussed.