Infection characteristics and diversity of arbuscular mycorrhizal fungi in the rhizosphere of Inula japonica in Songnen saline-alkaline grassland

In order to inspect the infection characteristic and diversity of arbuscular mycorrhizal (AM) fungi in the rhizosphere of Inula japonica in the Songnen saline-alkaline grassland in Zhaodong, Heilongjiang Province, roots and rhizosphere soil of I. japonica were collected from the southwest part of the grassland in July 2015. All roots, despite different soil pH levels, were infected by AM fungi. The infection rate reached 100% at pH 8.76, when the abundance of arbuscules and vesicles also reached maximums of 75.67% and 74.32% respectively. When the soil pH was 8.71, the infection rate was 85%, and the abundance of arbuscules and vesicles were at their lowest levels. 37 AM fungal species from 8 genera were isolated by mor-phological analysis. The 21 species belonging to Glomus accounted for 56.7% of all species, making Glomus the dominant genus; G. intraradices and G. etunicatum were the most common species. There were 6 species of Acaulospora (16.2% of all species), 3 species of Scutellospora (8.1% of all species), 2 species of each Pacispora and Entrophospora (each 5.4% of all species), and 1 species of each Gigaspora, Pacispora, and Entrophospora (each 2.7% of all species).