Samir K. Abdullah

Fungal root endophytes from natural vegetation in Mediterranean environments with special reference to Fusarium spp

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.

Extracellular enzymatic activity of aquatic and aero-aquatic conidial fungi

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 ofAegerita candida, Helicodendron giganteum andH. 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 tannic acid.

Two new species of Monascus from Iraq, with a key to known species of the genus

Monascus pallens sp. nov. and M. sanguineus sp. nov. are newly recognized species isolated from surface sediments of the Shatt-al-Arab river and its creeks near Basrah City, Iraq. Descriptions are provided, growth on denned media is measured and enzyme activities are investigated. A key to species is given.

A new species of Preussia from submerged plant debris

Preussia aquilirostrata is newly described from submerged plant debris in Iraq. A key to the identification of Preussia species with hairy ascomata is provided. Since Sporormiella is regarded as a synonym of Preussia , the new combinations Preussia lasiocarpa, P. pilosa, P. pilosella and P. chaetomioides are proposed.

The genus Melanocarpus

Melanocarpus is redescribed and a key to the four accepted species is given. A new species and combination are proposed.

A NEW SPECIES OF HELICOON FROM MALLORCA, SPAIN

A new aeroaquatic helicosporous hyphomycete, Helicoon maioricensis, from submerged decaying leaves in a small oligotrophic pond in an evergreen oak woodland in Mallorca, Spain is described and illu...

Exserohilum curvisporum sp. nov., a new hyphomycete from Iraq

The new species Exserohilum curvisporum , isolated from surface sediments consisting of a mixture of decomposed leaf fragments and sand of the Shatl-Al-Arab river in Basrah, Iraq is described and illustrated. It is distinguished from other Exserohilum species by its mostly strongly curved conidia often with a granular surface.

The aero-aquatic Helicodendron microsporum n. sp. from Mallorca, Spain

A new aero-aquatic helicosporous hyphomycete, Helicodendron microsporum , is described and illustrated from decaying leaves submerged in a small artificial pond surrounded by Quercus ilex and Pinus halepensis in Mallorca, Spain. It is characterized by branched conidiophores with chains of hyaline conidia eventually forming white clusters which do not break up even at maturity. It also has small conidia (8–10 μm diam.) consisting of a 2–2.5 μm thick filament which coils 1.5–2 times counter-clockwise. The main characters of the species are compared with 14 similar hyalosporous Helicodendron species.

Janetia obovata and Stachybotryna excentrica, two new hyphomycetes from submerged plant material in Spain

Janetia obovata and Stachybotryna excentrica, two new hyphomycetes from submerged litter collected in different Mediterranean localities in Spain, are described and illustrated. Janetia obovata possesses denticulate and dark pigmented conidiogenous cells characteristic of the genus, but is mainly distinctive in producing obovoid and unevenly pigmented conidia. Stachybotryna excentrica is hyaline and produces setae as do all members of the genus, but is distinctive by its small conidia that are cylindrical or ellipsoidal in front view and slightly allantoid in side view with a protuberant eccentric scar, and its long subcylindrical setae. A key to Stachybotryna species is provided.

A synopsis of the aero-aquatic genus Pseudaegerita and description of two new species

Two new species of the aero-aquatic anamorph genus Pseudaegerita, P. conifera sp. nov. and P. websteri sp. nov. are described and illustrated. Both species were found on submerged plant material in Spain. The new species are compared morphologically with the seven species now accepted in the genus.