Population Density and Root Colonization of AM Fungi in the Mycorrhizosphere of Semiarid Plant Species.

The ecological role of Arbuscular mycorrhizal fungi (AMF) in subtropical semiarid habitats is yet unexplored. Five subtropical semiarid plant species-Bambusa arundinacea (Retz.) Wild., Borassus flabellifer L., Eucalyptus globulus Labill, Euphorbia antiquorum L., and Vachellia leucophloea (Roxb.)-collected from the Pudukkottai district of south India were used in this study to examine the diversity, abundance, and root colonization of AMF. The study aims to determine the mycorrhizal status of these host plants, investigate the connection between root colonization and AMF spore quantity, and estimate the influence of edaphic factors, such as soil pH and nutrient availability, and AMF distribution. The conventional wet-sieving and decanting method was used to extract AMF spores, and the root-staining technique was used to assess root colonization. There were 62 morphotypes detected in five genera: Glomus, Acaulospora, Scutellospora, Gigaspora and Sclerocystis. Glomus was the most abundant genus in this study. B. arundinacea and V. leucophloea showed the highest root colonization rates (> 80%) and strong mycorrhizal interaction. In contrast, E. antiquorum had the highest spore abundance while B. arundinacea the lowest spore density. These results indicate that there is no direct correlation between root colonization and spore quantity in semiarid habitats because host compatibility and edaphic variables distinctly influence AMF colonization and sporulation. These findings emphasize the future utilization of native AMF as biofertilizer inoculants for sustainable agriculture and ecosystem resilience under water-scarce conditions and provide baseline ecological findings on AMF colonies in semi-arid habitats.