Root symbionts of Astragalus nebrodensis Guss. Strobl.- Wild Mediterranean legumes have a high potential in the re-naturalization of degraded or semi-arid ecosystems as they establish root symbiosis with nitrogen-fixing bacteria and mycorrhizal fungi which sinergically benefit plant nutrition and resistance to stress. Astragalus nebrodensis is a perennial shrub belonging to the Fabaceae, it is endemic to Sicily and its root symbionts are unknown. The objectives of this study are: 1) the analysis of the diversity of rhizobia of Astragalus nebrodensis; 2) the evaluation of the effects of inoculation of rhizobia and a commercial mycorrhizal fungus on the growth of plants in the nursery, using as a substrate the natural soil taken from the species areal. The morphometric analysis and the analysis of root symbiosis have shown that increased nodulation occurred in the absence of inoculum, i.e. by soil indigenous rhizobia. The rhizobia symbionts of A. nebrodensis were isolated and identified for the first time and affiliated to the genus Mesorhizobium sp. The high frequency of mycorrhization obtained by inoculating the commercial fungus Glomus intraradices increases plant survival at the expense of a slight depression of growth. The opposite effects were obtained with indigenous mycorrhizal fungi. The results of this work may provide a basis for the propagation of A. nebrodensis inoculated with beneficial symbionts, for the recovery of degraded ecosystems.
|Numero di pagine||15|
|Stato di pubblicazione||Published - 2013|