Isolation and Identification of Dominant Arbuscular Mycorrhizal Fungi in Some Trees in Region of Kiasar

The symbiotic arbascular mycorrhizal vesicular fungi caused growth improvement of plants and increased uptake some minerals by plants، and also improve the water relations of plants and protect them against diseases. In this study، Kiasar forest area selected due to abundant variety of plant species which located in northern part of Damghan city in Semnan province. About 56 sample collections were done in spring 1390. Almost 14 species of trees in this area were examined for the percentage of relative frequency، density accumulation، accumulation of abundance، species richness and evenness indices were calculated. The highest average of spore population with a mean 1382. 35 spores per 300 g soil sample was achieved followed by other soil samples from European black alder، wild myrobalan plum and orientalis beech. The highest rates of prevalence mycorrhizal (%F) and the average of accumulation mycorrhizal density (%M) was belongs to wild myrobalan plum with %66. 35 and %46. 79، respectively، while the lowest was elm tree with %69. 37 and %63. 58، respectively. Also، 8 species in species richness value were found in some trees like chestnut، white popular، Caucasian wingnut and melder، while in other soil samples of trees osuch as Ash and wild myrobalan plum were only four species. Of the 14 trees، 10 species of arbuscular mycorrhizal fungi were identified which 8 out of them were Glomus species. The highest relative abundance of species were belongs to G. aggregatum (%29. 30) and Gigaspora albida (%9. 34)، respectively.