The fast and continued progress of high-throughput sequencing (HTS) and the drastic reduction of its costs have boosted new and unpredictable developments in the field of plant pathology. The cost of whole-genome sequencing, which, until few years ago, was prohibitive for many projects, is now so affordable that a new branch, phylogenomics, is being developed. Fungal taxonomy is being deeply influenced by genome comparison, too. It is now easier to discover new genes as potential targets for an accurate diagnosis of new or emerging pathogens, notably those of quarantine concern. Similarly, with the development of metabarcoding and metagenomics techniques, it is now possible to unravel complex diseases or answer crucial questions, such as “What’s in my soil?”, to a good approximation, including fungi, bacteria, nematodes, etc. The new technologies allow to redraw the approach for disease control strategies considering the pathogens within their environment and deciphering the complex interactions between microorganisms and the cultivated crops. This kind of analysis usually generates big data that need sophisticated bioinformatic tools (machine learning, artificial intelligence) for their management. Herein, examples of the use of new technologies for research in fungal diversity and diagnosis of some fungal pathogens are reported.

Clavibacter michiganensis subsp. michiganensis (Smith) Davis et al. (Cmm) and Ralstonia solanacearum Yabuuchi et al. (Smith) (Rs) are important seed-borne bacterial pathogens of tomato (Solanum lycopersicum) listed as A2 pests in the EPPO (European and Mediterranean Plant Protection Organization) region. At present, there are few strategies to control these pathogens, and seed control with eco-compatible approaches is widely encouraged. In this work, the essential oils (EOs) of oregano (Origanum vulgare), garlic (Allium sativum), basil (Ocimum basilicum), cinnamon (Cinnamomum zeylanicum), clove buds (Syzygium aromaticum), thyme (Thymus vulgaris), and Trametes versicolor extract (Tve) were tested in vitro for their antimicrobial activity against Cmm and Rs (broth microdilution method). The tested EOs and the Tve extract caused a significant inhibition of bacterial growth, with very promising MBC (minimum bactericidal concentration) and MIC90 (minimum inhibitory concentration causing a 90% growth inhibition) values. Moreover, an in vivo germination test showed no major reduction in seed germination when the substances were applied as seed treatment. A rapid molecular screening method has been developed, through real-time PCR, for the specific quantification of Cmm in the presence of a vegetable matrix to test in vivo the antimicrobial efficacy of oregano and cinnamon oil on seed treatment without resorting to whole plant essays, which are time- and space-consuming.

Using morphological and cultural characteristics for identification, 36 Fusarium isolates were recovered from diseased roots, stems, and seeds of soybean from several localities throughout Vojvodina Province, Serbia. Based on molecular characterization, 12 Fusarium species were identified: F. acuminatum, F. avenaceum, F. commune, F. equiseti, F. graminearum, F. incarnatum, F. oxysporum, F. proliferatum, F. solani, F. sporotrichioides, F. subglutinans, and F. tricinctum. The elongation factor 1-α–based phylogeny grouped the isolates into 12 well-supported clades, but polymorphisms among sequences in some clades suggested the use of the species complex concept: (i) F. incarnatum-equiseti species complex (FIESC)—F. incarnatum and F. equiseti; (ii) F. oxysporum species complex (FOSC)—F. oxysporum; (iii) F. solani species complex (FSSC)—F. solani; and (iv) F. acuminatum/F. avenaceum/F. tricinctum species complex (FAATSC)—F. acuminatum, F. avenaceum, and F. tricinctum. Pathogenicity tests showed that the most aggressive species causing soybean seed rot were F. sporotrichioides, F. graminearum, FIESC, and F. avenaceum. Furthermore, F. subglutinans, FSSC, and F. proliferatum showed a high percentage of pathogenicity on soybean seeds (80 to 100%), whereas variability in pathogenicity occurred within isolates of F. tricinctum. FOSC, F. commune, and F. acuminatum had the lowest pathogenicity. To our knowledge, this is the first study of the characterization of Fusarium species on soybean in Serbia. This study provides valuable information about the composition of Fusarium species and pathogenicity that will be used in further research on soybean resistance to Fusarium-based diseases.

The origin of the cucumber (Cucumis sativus L.) has been attributed to Africa, China, India, or the Near East. Cucumbers are now grown throughout the world using fields or greenhouse culture. In It...

The rapid expansion of pomegranate (Punica granatum L.) cultivation in central and southern Italy has revealed emerging phytosanitary challenges, including “pomegranate wood decay syndrome”, characterised by cortical cankers, wood browning, and progressive plant decline. This study investigates the fungal microbiota associated with symptomatic pomegranate wood using a combined approach of traditional fungal isolation and ITS2 metabarcoding analysis. Samples from two orchards in Lazio were examined, revealing a complex fungal community with a high prevalence of Neofusicoccum parvum (putative) and species belonging to the genus Diaporthe. Pathogenicity tests confirmed the role of N. parvum in causing significant wood browning, while other isolates showed variable virulence. Statistical analyses validated the pathogenicity of select isolates, with the putative Diaporthe eres (Nitschke) consistently demonstrating potential pathogenic activity across all trials. Metabarcoding identified 289 taxa, highlighting a richer fungal diversity in the symptomatic wood compared to the asymptomatic sections. Notably, Coniella granati, previously implicated in pomegranate decline, was absent in the studied orchards. The findings reveal that pomegranate wood decay is a complex syndrome driven by fungal pathogens and environmental stressors, such as low temperatures. This study highlights the value of integrative approaches for understanding and managing fungal-associated wood diseases in pomegranate orchards.