Surveys (in 2002 and 2003) were performed for fungal endophytes in roots of 24 plant species growing at 12 sites (coastal and inland soils, both sandy soils and salt marshes) under either water or salt stress in the Alicante province (Southeast Spain). All plant species examined were colonized by endophytic fungi. A total of 1830 fungal isolates were obtained and identified by morphological and molecular [internal transcribed spacer (ITS) and translation elongation factor-1alpha gene region (TEF-1alpha) sequencing] techniques. One hundred and forty-two fungal species were identified, belonging to 57 genera. Sterile mycelia were assigned to 177 morphospecies. Fusarium and Phoma species were the most frequent genera, followed by Aspergillus, Alternaria and Acremonium. Fungal root endophytic communities were influenced by the soil type where their respective host plants grew, but not by location (coastal or inland sites). Fusarium oxysporum, Aspergillus fumigatus and Alternaria chlamydospora contributed most to the differences found between endophytic communities from sandy and saline soils. Host preference was found for three Fusarium species studied. Fusarium oxysporum and Fusarium solani were especially isolated from plants of the family Leguminosae, while Fusarium equiseti showed a preference for Lygeum spartum (Gramineae). In some cases, specificity could be related to intra-specific variability as shown by sequencing of the TEF-1alpha in the genus Fusarium.

Nineteen species of aquatic and areo-aquatic conidial fungi were tested for their ability to produce extracellular enzymes which degrade cellulose, starch, lipids, proteins and tannic acid. The cellulolytic activity was determined by using both solid and liquid media. The activity of other enzymes was examined using solid media. Two-thirds of the species were able to hydrolyze soluble cellulose (CMC) incorporated in solid and liquid media with varying degrees of activity. Extracellular culture filtrates ofdegetita candida, Helicodendron giganteum and H. tubulosum contained a Cl-Cx enzyme complex that could degrade both soluble cellulose (CMC) and crystalline cellulose (filter paper). Lipase activity was demonstrated by 11 species. Fourteen of the species showed activity for amylase and protease, but only 11 of the 16 were capable of degrading tarmic acid.

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Abstract:The present study reports the frequent isolation of the two date palm pathogens Thielaviopsis paradoxa (de Seynes) Hohn and T. punctulata (Hennebert) Paulin, Harrington et McNew from soil of date palm plantations at Elx, south-east Spain, using dilution plate, direct soil plating or by soil treatment either with acetic acid or phenol. The two species showed a high isolation rate.T. punctulata detected from all samples (100% isolation rate), whereas, T. paradoxa showed 52% isolation rate.Total fungal colony count, ranged from 1.1x10 5 -6 x10 5 , CFU/g dry soil. Out of these, T. punculata comprised between 0.2-3.2% and T. paradoxa, between 0.5-4.4%.Both species were characterized by development of thick-walled aleuroconidia either singly (T. punctulata) or in chains (T. paradoxa) in addition to the phialoconidia. The widespread occurrence of the two pathogens in soil may contribute to the possibility of infection of newly transplanted offshoots of date palms.

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