Arbuscular Mycorrhizal (AM) Diversity in Acacia nilotica subsp. indica (Benth.) Brenan under Arid Agroecosystems of Western Rajasthan

Abstract

Arbuscular mycorrhizal (AM) fungi associated with Acacia nilotica subsp. indica (Babul) were assessed for their qualitative andquantitative distribution from nine districts of Rajasthan. A total of one species of Acaulospora, two species of Gigaspora,seventeen species of Glomus, four species of Sclerocystis and two species of Scutellospora were recorded. A high diversity ofAM fungi was observed and it varied at different study sites. Among these five genera, Glomus occurred most frequently. Glomusfasciculatum,G. aggregatum, and G. mosseae were found to be the most predominant AM fungi in infecting A. nilotica subsp.indica.G. fasciculatum,Sclerocystis was found in all the fields studied, while Gigaspora species and Scutellospora species werefound only in few sites. The more number (26) of AM fungal species were isolated and identified from Pali whereas, only elevenspecies (11) were found from Barmer. The spore density was varied between 163 to 480 propagules (100 g-1) soil. The per centroot colonization was varied (40 to 78 %) from place to place. The pH of study area was ranged between 7.58 to 8.69; EC wasrecorded from 0.09 to 0.73 (dSm-1); per cent OC ranged from 0.09 to 0.50 and available P content varied from 3.81 to 5.12 mg kg-1for A. nilotica subsp. indica. A significant correlation of AM population was observed with root colonization and per centorganic carbon while other variables studies had a non-significant correlation with total AM population