IDENTIFICATION AND CHARACTERIZATION OF ARBUSCULAR MYCORRHIZAE IN THE MAIN OLIVE GROWING AREA OF CALABRIA (ITALY)

Arbuscular mycorrhizal fungi (AM) are naturally present in all soils and enter into mutualistic symbiosis with the roots of most plants. The olive tree is a highly mycotrophic plant, over 80% of its root system is affected by the symbiosis, therefore the olive tree is considered mycorrhizal-dependent. This characteristic has contributed to its spread in marginal environments and in less fertile soil. The AM fungi are known to positively influence plant growth, improving the absorption of nutrients, particularly phosphorus, by increasing the soil volume explored from the roots, and to protect the plants against biotic and abiotic stress. In this study, it was considered useful to identify and characterize the symbiotic fungi present in different Calabrian olive groves in order to increase knowledge regarding soil fertility and biodiversity and to obtain new inocula of commercial interest for the olive tree nursery production systems. Identification and characterization of soil mycorrhiza are done by molecular approaches and amplification of the ITS region of ribosomal DNA allowed the identification of mycorrhizae in a unique way. Using this technique, it was possible to analyze the diversity and phylogeny of AM fungi present in the main area of the region of Calabria. Low biodiversity of the endo-mycorrhizae was detected among the olive groves tested regardless of the different chemical and physical characteristics of the soils. Despite the anthropic activities, the soils showed a medium-high presence of spores belonging to genera such as Glomus, Scutellospora, Paraglomus and Ambispora.