Peguero-Pina José Javier, Sancho-Knapik Domingo, Barrón Eduardo, Camarero Julio Jesús, Vilagrosa Alberto, Gil-Pelegrín Eustaquio
Departament de Biologia, Universitat de les Illes Balears, Carretera de Valldemossa km. 7.5, 07071 Palma de Mallorca, Spain Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, 50059 Zaragoza, Spain.
Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria, Gobierno de Aragón, 50059 Zaragoza, Spain.
Ann Bot. 2014 Aug;114(2):301-13. doi: 10.1093/aob/mcu108. Epub 2014 Jun 18.
Several studies show apparently contradictory findings about the functional convergence within the Mediterranean woody flora. In this context, this study evaluates the variability of functional traits within holm oak (Quercus ilex) to elucidate whether provenances corresponding to different morphotypes represent different ecotypes locally adapted to the prevaling stress levels.
Several morphological and physiological traits were measured at leaf and shoot levels in 9-year-old seedlings of seven Q. ilex provenances including all recognized morphotypes. Plants were grown in a common garden for 9 years under the same environmental conditions to avoid possible biases due to site-specific characteristics.
Leaf morphometry clearly separates holm oak provenances into 'ilex' (more elongated leaves with low vein density) and 'rotundifolia' (short and rounded leaves with high vein density) morphotypes. Moreover, these morphotypes represent two consistent and very contrasting functional types in response to dry climates, mainly in terms of leaf area, major vein density, leaf specific conductivity, resistance to drought-induced cavitation and turgor loss point.
The 'ilex' and 'rotundifolia' morphotypes correspond to different ecotypes as inferred from their contrasting functional traits. To the best of our knowledge, this is the first time that the combined use of morphological and physiological traits has provided support for the concept of these two holm oak morphotypes being regarded as two different species.
多项研究显示，关于地中海木本植物区系内的功能趋同，存在明显相互矛盾的研究结果。在此背景下，本研究评估了圣栎（Quercus ilex）功能性状的变异性，以阐明对应不同形态型的种源在当地是否代表适应了主要胁迫水平的不同生态型。
在包括所有已确认形态型的7个圣栎种源的9年生幼苗上，测定了叶片和枝条水平的多个形态和生理性状。将植株在相同环境条件下的共同园地里种植9年，以避免因特定地点特征可能产生的偏差。
叶片形态测量法明确地将圣栎种源分为“ilex”（叶片更狭长、叶脉密度低）和“rotundifolia”（叶片短圆、叶脉密度高）形态型。此外，这些形态型在应对干旱气候时代表两种一致且差异极大的功能类型，主要体现在叶面积、主脉密度、叶片比导率、抗旱性诱导空化抗性和膨压丧失点方面。
从“ilex”和“rotundifolia”形态型截然不同的功能性状推断，它们对应不同的生态型。据我们所知，这是首次通过结合形态和生理性状，为将这两种圣栎形态型视为两个不同物种的概念提供支持。
