Correlation of Soil Physico-chemical Factors with AM Fungal Diversity in Ailanthus excelsa Roxb. Under Different Agroecological Zones of Western Rajasthan

Abstract

Arbuscular mycorrhizal (AM) fungi associated with Ailanthus excelsa Roxb (Ardu) were assessed for their qualitative and quantitative distribution from eight districts of Rajasthan. A total of three species of Acaulospora, two species of Gigaspora, fourteen species of Glomus, four species of Sclerocystis and two species of Scutellospora were recorded. A high diversity of AM fungi was observed and it varied at different study sites. Among these five genera, Glomus occurred most frequently. Glomus fasciculatum and G. mosseae were found to be the most predominant AM fungi in infecting A. excelsa. G. fasciculatum, Sclerocystis was found in all the fields studied, while Gigaspora species and Scutellospora species were found only in few sites. The maximum number (22) of AM fungal species were isolated and identified from Sikar whereas, only ten species (10) were found from Nagaur. The spore density was varied between 195 to 682 propagules (100 g-1) soil. The percent root colonization was varied (47 to 79 %) from place to place. The pH of study area was ranged between 7.82 to 8.79; EC was recorded from 0.13 to 0.62 (dSm-1); Percent OC ranged from 0.22 to 0.39 and available P content varied from 4.1 to 5.36 mg kg-1 for A. excelsa. A significant correlation of AM population was observed with root colonization, percent organic carbon and pH while other variables under study had a non-significant correlation with total AM population.