title: Fungal diversity in adult date palm (Phoenix dactylifera L.) revealed by culture-dependent and culture-independent approaches.
abstract: 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).
authors.affiliation: Laboratoire de Biotechnologies Végétales Appliquées à l'Amélioration des Cultures LBVAAC, Faculté des Sciences de Sfax, B.P. 1171, 3000 Sfax, Tunisia; Laboratoire de Microorganismes et de Biomolécules, Centre de Biotechnologie de Sfax, Université de Sfax, Route Sidi Mansour, B.P. 1177, 3018 Sfax, Tunisia; Laboratoire de Phytopathologie Oasienne, Centre Régional de Recherches en Agriculture Oasienne à Degache, Degache 2260, Tunisia; Plateforme Séquençage-Génotypage SFR "Montpellier Environnement Biodiversité", ISEM, Université de Montpellier 2, 34095 Montpellier, France; UMR 5119, Université de Montpellier 2, Sciences et Techniques, pl E. Bataillon, CC093, 34095 Montpellier, France.
authors.forename: Ines
authors.initials: I
authors.lastname: Ben Chobba
authors.forename: Amine
authors.initials: A
authors.lastname: Elleuch
authors.forename: Imen
authors.initials: I
authors.lastname: Ayadi
authors.forename: Lamia
authors.initials: L
authors.lastname: Khannous
authors.forename: Ahmed
authors.initials: A
authors.lastname: Namsi
authors.forename: Frederique
authors.initials: F
authors.lastname: Cerqueira
authors.forename: Noureddine
authors.initials: N
authors.lastname: Drira
authors.forename: Néji
authors.initials: N
authors.lastname: Gharsallah
authors.forename: Tatiana
authors.initials: T
authors.lastname: Vallaeys
mesh_terms: D028023:Arecaceae / Q000254:growth & development / Q000382:microbiology*; D044822:Biodiversity; D005658:Fungi / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D059013:Microbial Consortia / Q000235:genetics*; D018515:Plant Leaves / Q000254:growth & development / Q000382:microbiology*; D018517:Plant Roots / Q000254:growth & development / Q000382:microbiology*