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The relationships between arbuscular mycorrhizal fungi (AMF) development levels and soil physicochemical properties remain poorly known in citrus. In our study, rhizospheric soil and root samples of Maltaise sanguine blood orange (Citrus sinensis) have been collected from thirteen representative sites in the Cape region in the Northeastern part of Tunisia. Soil physicochemical properties, spore density (SD), AM colonization rate, and the contents of easily extractable glomalin-related soil protein (EE-GRSP) and total glomalin-related soil protein (T-GRSP) were determined in the rhizosphere soils. The results indicated that SD, the frequency of mycorrhizal colonization, and T-GRSP concentration were significantly different among the study sites. Pearson correlation analysis showed that SD was negatively correlated with T-GRSP and available phosphorus. The frequency of mycorrhizal colonization was positively correlated with soil pH. The intensity of mycorrhizal colonization was negatively correlated with the soil concentration of exchangeable Na while arbuscules abundance was positively correlated with soil-available phosphorus. T-GRSP was positively correlated with available phosphorus, soil organic matter, and total nitrogen while negatively correlated with soil pH. The obtained results demonstrated that soil physicochemical properties are important in determining AMF development in Maltaise citrus orchards.

Identification of whole durum wheat flour landrace origin based on specific chemical markers is important for flour authentication, breeding program design and food manufacturing process. Here, this investigation aimed to comprehensively analyze primary and secondary metabolites of three different-Tunisian whole-wheat flour landraces (Beskri, JnehKhottifa and Mahmoudi) using gas chromatography coupled with time-of-flight mass spectrometry (GC-TOFMS). The discrimination of non-trageting metabolite profiles across these three landraces was confirmed using principal component analysis, hierarchical clustering analysis, partial least square-discriminant analysis, and support vector machine. Metabolite profile analysis showed that the highest accumulation of nutraceutical organic and amino acids content, as well as the highest antioxidant activity were observed in the colored wheat flours of JnehKhottifa and Beskri landraces. This later can be considered as the sweetest durum wheat landrace due to its high free sugars content. However, the highest phenolic amount in white flour of Mahmoudi could gives this landrace a partiuclatrity as phenolic-rich new durum wheat variety for future breeding programmes. Network-based correlation analysis identified metablites hubs including mostly amino acids and indicated that these metabolites played significant roles in the authentication of whole-wheat flours from Tunisian durum wheat landraces. In conclusion, our approach supports the usefulness of GC-TOFMS-based metabolite profiling in determining the authenticity and botanical origin of local durum landraces and also for identifing specific metabolites valuable for cereal breeding strategies towards sustainable agriculture.