Variations in Allelochemical Composition of Leacha

Authors: Catherine Fernandez Yogan Monnier Elena Ormeño Virginie Baldy Stéphane Greff Vanina Pasqualini JeanPhilippe Mévy Anne BousquetMélou

Publish Date: 2009/07/23

Volume: 35, Issue: 8, Pages: 970-979

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Abstract

We investigated changes in the occurrence of allelochemicals from leachates of different Pinus halepensis organs taking into account the stages of pine stand age ie young   15yearsold middle age ± 30years and old   60yearsold GCMS analysis of aqueous extracts revealed approx 59 components from needles and roots The major constituents were divided into different phytochemical groups—phenolics 50 fatty acids 44 and terpenoids Further analyses were carried out to characterize the distribution of allelochemicals in different organs and P halepensis successional stages Roots and needles had two distinct chemical profiles while needle leachates were composed mainly of oxygenated terpenoids eg αeudesmol αcadinol and αterpineol Roots mainly contained fatty acids Needles from young pine stands had the highest content of monoterpenes suggesting their role as potential allelochemicals that could help young pine stands to establish Pooling the different functional chemical groups showed that needles and to a lesser extent old roots had higher chemical diversity than the roots of young and mediumaged pines The highest diversity in phenolic constituents and fatty acids was in young needles Dchem = 238 Finally caffeic acid a compound that has allelopathic properties was found in aqueous extracts at high concentrations in both young needles and old roots The role of this compound in mediation of biological interactions in P halepensis ecosystem functioning is discussedThis study was funded by the CNRS within the framework of the Zone Atelier “Arrièrepays Méditerranéen” We are grateful to the Luberon Natural Regional Park The authors are indebted to many private owners who granted permission for work in their forest We also thank Prof David Mouillot University of Montpellier II for his help in statistical analysis and Stephanie Jim from University of California Berkeley for proofreading the English

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