Fungal diversity in adult date palm(Phoenix dactylifera L.) revealed by culture-dependent and culture-independent approaches  

作　　者：Ines BEN CHOBBA Amine ELLEUCH Imen AYADI Lamia KHANNOUS Ahmed NAMSI Frederique CERQUEIRA Noureddine DRIRA Néji GHARSALLAH Tatiana VALLAEYS 

机构地区：[1]Laboratoire de Biotechnologies Végétales Appliquées à l'Amélioration des Cultures LBVAAC, Faculté des Sciences de Sfax,B.P. 1171, 3000 Sfax, Tunisia [2]UMR 5119, Université de Montpellier 2, Sciences et Techniques, pl E. Bataillon,CC093, 34095 Montpellier, France [3]Laboratoire de Microorganismes et de Biomolécules, Centre de Biotechnologie de Sfax, Université de Sfax, Route Sidi Mansour,B.P. 1177, 3018 Sfax, Tunisia [4]Laboratoire de Phytopathologie Oasienne, Centre Régional de Recherches en Agriculture Oasienne à Degache,Degache 2260, Tunisia [5]Plateforme Séquen age-Génotypage SFR "Montpellier Environnement Biodiversité", ISEM, Université de Montpellier 2,34095 Montpellier, France

出　　处：《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》2013年第12期1084-1099,共16页浙江大学学报（英文版）B辑（生物医学与生物技术）

基　　金：supported by EGIDE(No.18470SA),CMCU(No.08G908);the Tunisian Ministry of Higher Education

摘　　要：Endophytic flora plays a vital role in the colonization and survival of host plants, especially in harsh environments, such as arid regions. This flora may, however, contain pathogenic species responsible for various troublesome host diseases. The present study is aimed at investigating the diversity of both cultivable and non-cultivable endophytic fungal floras in the internal tissues(roots and leaves) of Tunisian date palm trees(Phoenix dactylifera). Accordingly, 13 isolates from both root and leaf samples, exhibiting distinct colony morphology, were selected from potato dextrose agar(PDA) medium and identified by a sequence match search wherein their 18S–28S internal transcribed spacer(ITS) sequences were compared to those available in public databases. These findings revealed that the cultivable root and leaf isolates fell into two groups, namely Nectriaceae and Pleosporaceae. Additionally, total DNA from palm roots and leaves was further extracted and ITS fragments were amplified. Restriction fragment length polymorphism(RFLP) analysis of the ITS from 200 fungal clones(leaves: 100; roots: 100) using HaeIII restriction enzyme revealed 13 distinct patterns that were further sequenced and led to the identification of Alternaria, Cladosporium, Davidiella(Cladosporium teleomorph), Pythium, Curvularia, and uncharacterized fungal endophytes. Both approaches confirmed that while the roots were predominantly colonized by Fusaria(members of the Nectriaceae family), the leaves were essentially colonized by Alternaria(members of the Pleosporaceae family). Overall, the findings of the present study constitute, to the authors' knowledge, the first extensive report on the diversity of endophytic fungal flora associated with date palm trees(P. dactylifera).Endophytic flora plays a vital role in the colonization and survival of host plants, especial y in harsh en-vironments, such as arid regions. This flora may, however, contain pathogenic species responsible for various trou-blesome host diseases. The present study is aimed at investigating the diversity of both cultivable and non-cultivable endophytic fungal floras in the internal tissues （roots and leaves） of Tunisian date palm trees （Phoenix dactylifera）. Accordingly, 13 isolates from both root and leaf samples, exhibiting distinct colony morphology, were selected from potato dextrose agar （PDA） medium and identified by a sequence match search wherein their 18S-28S internal transcribed spacer （ITS） sequences were compared to those available in public databases. These findings revealed that the cultivable root and leaf isolates fel into two groups, namely Nectriaceae and Pleosporaceae. Additional y, total DNA from palm roots and leaves was further extracted and ITS fragments were amplified. Restriction fragment length polymorphism （RFLP） analysis of the ITS from 200 fungal clones （leaves： 100; roots： 100） using HaeIII restriction enzyme revealed 13 distinct patterns that were further sequenced and led to the identification of Alternaria, Cladosporium, Davidiel a （Cladosporium teleomorph）, Pythium, Curvularia, and uncharacterized fungal endophytes. Both approaches confirmed that while the roots were predominantly colonized by Fusaria （members of the Nectri-aceae family）, the leaves were essential y colonized by Alternaria （members of the Pleosporaceae family）. Overal , the findings of the present study constitute, to the authors’ knowledge, the first extensive report on the diversity of endophytic fungal flora associated with date palm trees （P. dactylifera）.

关 键 词：Date palm tree(Phoenix dactylifera) Endophytic cultivable fungi rDNA internal transcribed spacer(ITS) Phylogenetic analysis Total DNA diversity analysis 

分 类 号：Q931[生物学—微生物学]