Changes in water relations, photosynthesis and leaf anatomy induced by intermittent drought in two olive cultivars

Photosynthetic rate, water relations parameters as well as leaf anatomical characteristics were studied in two olive cultivars (Olea europea, cv 'Koro neiki' and cv 'Mastoidis') grown under water stress conditions. No signific ant differences were obtained between the two cultivars concerning their ab ility for turgor maintenance under water stress conditions. 'Koroneiki' see ms to maintain higher photosynthetic rates with lower values of stomatal co nductance than 'Mastoidis', a fact that could be attributed to differentiat ion in leaf anatomy induced by water stress conditions. The fraction of mes ophyll volume represented by intercellular air spaces as well as the surfac e area of mesophyll cell walls exposed to intercellular spaces was larger i n 'Koroneiki' than in 'Mastoidis'. The possibility of using leaf anatomical characteristics as selection factors for olive cultivars grown under droug ht conditions is discussed. (C) 1999 Elsevier Science B.V, All rights reser ved.