Abstract
Fungi are an important part of the Eco world system we live in. Viruses in fungi probably have existed for a long time but they were discovered only recently. This study was designed to isolate and identify some mycophages from some soils collected from different regions of KSA and could be considered as the first record in KSA. A number of six soil samples from different regions (Taif, Jeddah, Makkah) in KSA were collected and subjected to physical, chemical and microbiological analyses. A number of ten fungal isolates were selected, highly purified, and then their cultural and morphological (via light microscopy) characters were determined. The nucleotide sequences of the 18S rDNA gene of these fungal isolates was also determined. The presence of viruses (mycophages) in the mycelia of the identified fungal isolates was detected via electron microscopy for the partially purified viruses preparation. The highest fungal total count was found in soil sample (JG1) from Jeddah followed by soil (MH1) from Makkah, soil sample (TA1) from Taif. Cultural charcters and light microscopy revealed that the ten fungal isolates were belonging to the following species: F. oxysporum (two isolates), F. solani (one isolate), Tricoderma sp. (one isolates), Alternaria alternate (one isolate), Aspergillus niger (one isolate), Penicillium commune (two isolates), P. polonicum (one isolate), and P. expansum (one isolate). The lengths of 18S rRNA gene of ten fungal isolates were ranged from 480 to 680 nts except for the P. expansum isolate which showed approximately full lenthg of 1568 nts. The similarities between the fungal isolates and those similar in GenBank were ranged from 99 to 100% and confirmed the biological identification of the isolates under investigation as aboveformentioned. Electron microscopy of the virus suspensions prepared from the mycelia of the ten identified strains showed the presence of spherical or isometric virus-like particles in the virus suspension of Penicillium polonicum strain only. As a conclusion, combination of cultural growth, light and microscopy and use of 18S rRNA gene were more than effective in identification of the fungal strains. On the other hand, mycoviruses could be considere as hidden particles in the mycelia with low concentrations.