Abstract
Distribution and colonization of arbuscular mycorrhizal fungi were studied under plant vegetation, which was found growing naturally in the near edges of the old road between Jeddah to Mecca at western of Saudi Arabia kingdom, during the period between May to September 2013. One hundred and twenty five roots and rhizospheric soils of 12 plant species belonging to 8 families from 25 sites at different 3 locations were collected and examined. Mycorrhizal fungi were recorded in 11 taxa, 3 genera, 3 families, 2 orders, one class and one phylum from all sites. On the generic level, Glomus was the dominant genus in rhizospheric soil, which Glomus sinusum (Gerd. & Bakshi) Almeida & Schenck and G. macrocarpum Tulasne & Tulasne were the dominant species associated with examined plant species. The plants to family Asclepiadaceae were contained of 43.85% from total collected spores in all study sites. On the other hand the average of distribution species of mycorrhizal fungi in all examined plants between 2 and 5 species for plant family. The G. macrocarpum was recorded in 10 sites out of 25 sites collected from different locations.