Structural and functional plasticity of Quercus ilex seedlings of different provenances in Italy

Functional and structural leaf traits of Quercus ilex seedlings originated from parent plant acorns from three different localities in Italy were studied. Acorns from three different localities along a gradient from the north to the south of Italy: Nago (site A) in the Garda Lake region at the northernmost limit of holm oak distribution area in Italy, Castelporziano near Rome (site B), at the centre of the distribution area, and Frassanito near Otranto (site C), in a drier area in the south of Italy. Morphological and anatomical leaf traits differed between the provenances with a higher leaf mass area, total leaf thickness and the ratio of palisade to mesophyll thickness in the driest provenance (C seedlings). These traits gave C seedlings a higher water use efficiency, relative water content at predawn and photosynthetic rates than the other provenances in high air temperature conditions. The smaller leaf area of A seedlings seemed to have a higher photosynthetic capacity in low air temperature conditions than B and C seedlings. Growth analysis underlined a higher shoot relative growth rate in B seedlings explaining the highest shoot length and leaf number per shoot. The plasticity index [sensu Valladares et al. (2000) Ecology 81:1925–1936] for physiological traits of the seedlings was higher than morphological and anatomical traits, but the largest differences in plasticity among ecotypes were found for morphological and anatomical traits. The ecotypes of Q. ilex studied here seemed to integrate, at leaf level, functions of growth activity, morphology and physiology related to the climate of the original provenance.

[1]  Mark G. Tjoelker,et al.  Growth and physiology of Picea abies populations from elevational transects: common garden evidence for altitudinal ecotypes and cold adaptation , 1998 .

[2]  Plasticity and genotypic variation in photosynthetic behaviour of an early and a late successional species of Polygonum , 1983, Oecologia.

[3]  L. Gratani.  Structural and ecophysiological plasticity of some evergreen species of the mediterranean maquis in response to climate , 1995 .

[4]  W. Larcher.  Temperature stress and survival ability of Mediterranean sclerophyllous plants , 2000 .

[5]  F. Valladares,et al.  Low leaf-level response to light and nutrients in Mediterranean evergreen oaks: a conservative resource-use strategy? , 2000, The New phytologist.

[6]  C. Werner,et al.  Two different strategies of Mediterranean macchia plants to avoid photoinhibitory damage by excessive radiation levels during summer drought , 1999 .

[7]  W. Larcher,et al.  Responses of Quercus ilex from Different Provenances to Experimentally Imposed Water Stress , 2003, Biologia Plantarum.

[8]  J. Thompson,et al.  Phenotypic plasticity in relation to ploidy level and corm production in the perennial grass Arrhenatherum elatius , 1996 .

[9]  R. Teskey,et al.  Water relations of loblolly pine seedlings from diverse geographic origins. , 1986, Tree physiology.

[10]  Carl D. Schlichting,et al.  The Evolution of Phenotypic Plasticity in Plants , 1986 .

[11]  R. Slatyer,et al.  Altitudinal Variation in the Photosynthetic Characteristics of Snow Gum, Eucalyptus pauciflora Sieb. Ex Spreng. II. Effects of Growth Temperature Under Controlled Conditions , 1977 .

[12]  S. Sabaté,et al.  Leaf Traits and Canopy Organization , 1999 .

[13]  L. Gratani,et al.  Relationship between leaf life-span and photosynthetic activity of Quercus ilex in polluted urban areas (Rome). , 2000, Environmental pollution.

[14]  J. Pereira,et al.  Plant Responses to Drought Under Climate Change in Mediterranean-Type Ecosystems , 1995 .

[15]  P. Castro-Díez,et al.  Leaf morphology, leaf chemical composition and stem xylem characteristics in two Pistacia (Anacardiaceae) species along a climatic gradient. , 1998 .

[16]  W. Hartung,et al.  Identification of drought-sensitive beech ecotypes by physiological parameters. , 2002, The New phytologist.

[17]  M. G. Ryan,et al.  Tree and forest functioning in response to global warming. , 2001, The New phytologist.

[18]  J. Terradas,et al.  The influence of summer and winter stress and water relationships on the distribution of Quercus ilex L. , 1992, Vegetatio.

[19]  P. Hari,et al.  Structural adaptation rather than water conservation was observed in Scots pine over a range of wet to dry climates , 1999, Oecologia.

[20]  G. F. Sassenrath-Cole,et al.  A Comparison of Leaf Anatomy in Field-grown Gossypium hirsutum and G. barbadense , 2000 .

[21]  A. S. Evans,et al.  The Evolution of Plant Ecophysiological Traits: Recent Advances and Future Directions , 2000 .

[22]  G. Wühlisch,et al.  Variation in temperature sum requirement for flushing of beech provenances , 1995 .

[23]  D. Kuiper,et al.  Phenotypic plasticity in a physiological perspective , 1988 .

[24]  A. Bombelli,et al.  Forecasted Stability of Mediterranean Evergreen Species Considering Global Changes , 2001 .

[25]  F. Romane,et al.  Quercus ilex L. ecosystems: function, dynamics and management , 1992, Advances in vegetation science.

[26]  R. Hunt.  Plant Growth Curves: The Functional Approach to Plant Growth Analysis , 1983 .

[27]  M. Beniston,et al.  Global change and protected areas , 2001 .

[28]  F. Valladares,et al.  Exploring Phenotypic Plasticity in the LichenRamalina capitata: Morphology, Water Relations and Chlorophyll Content in North- and South-facing Populations , 1997 .

[29]  L. Gratani.  Leaf and shoot growth dynamics of Quercus ilex L. , 1996 .

[30]  M. Fotelli,et al.  Water stress responses of seedlings of four Mediterranean oak species. , 2000, Tree physiology.

[31]  Robert W. Pearcy,et al.  Plastic Phenotypic Response to Light of 16 Congeneric Shrubs From a Panamanian Rainforest , 2000 .

[32]  S. Sultan.  Phenotypic plasticity for plant development, function and life history. , 2000, Trends in plant science.

[33]  J. Tenhunen,et al.  Site-specific water relations and stomatal response of Quercus ilex in a Mediterranean watershed. , 1994, Tree physiology.

[34]  W. Larcher,et al.  Photosynthesis as a temperature indicator in Quercus ilex L. , 2000 .

[35]  P. Tomlinson,et al.  Tropical Trees and Forests: An Architectural Analysis , 1978 .

[36]  H. Mooney,et al.  PHOTOSYNTHETIC ACCLIMATION OF PLANTS OF DIVERSE ORIGIN , 1964 .

[37]  P. Reich,et al.  Whole-plant CO2 exchange of seedlings of two Pinus sylvestris L. provenances grown under simulated photoperiodic conditions of 50° and 60° N , 1992, Trees.

[38]  A. Kremer,et al.  Latitudinal and altitudinal variation of bud burst in western populations of sessile oak (Quercus petraea (Matt) Liebl) , 1996 .

[39]  Variation in the genetic structure and reproductive biology of holm oak populations , 1992, Vegetatio.

[40]  D. Levin,et al.  Genetic and phenotypic correlations in plants: a botanical test of Cheverud's conjecture , 1998, Heredity.

[41]  J. García-Plazaola,et al.  Effects of drought on photoprotective mechanisms in European beech (Fagus sylvatica L.) seedlings from different provenances , 2000, Trees.