This work aimed to verify the genetic variability of Fusarium oxysporum f. sp. cubense isolates based on aggressiveness and molecular data (ISSR, SSR and sequencing of the TEF-1α gene). A total of 152 isolates collected from bananaproducing areas in the north and south regions of the state of Santa Catarina, Brazil, were compared. Isolates were collected from plants belonging to the Pome and Cavendish subgroups. Pathogenicity was confirmed for all isolates, and morphological traits confirmed the identity of the fungus. Greenhouse assays allowed classification of the isolates into three groups according to their aggressiveness. Results from ISSR, SSR and DNA sequencing revealed less variation since the majority of the isolates displayed 100 % similarity. Among the markers, ISSR and SSR were the most polymorphic in terms of differentiating with a larger percentage of dissimilarity. Results from aggressiveness tests indicated a tendency towards a consistent structure according to host or geographical origin of the isolates. No relationship between DNA markers and aggressiveness of isolates could be established.

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Banana is one of the most popular fruits in the world but has been substantially impaired by Panama disease in the last years. Fusarium oxysporum f. sp. cubense (Foc) is the causal agent and colonizes banana cultivars from many subgroups with different aggressiveness levels, often leading to plant death while compromising new crops in infested areas. This study has evaluated the ability of MALDI-MS protein and lipid fingerprinting to provide intraspecies classification of Foc isolates and to screen biomolecules related to host-pathogen relationship. The MS data, when inspected via partial least square discriminant analysis (PLS-DA), distinguished the isolates by aggressiveness as well as by specific location and host. Although both lipids and proteins show discriminating tendencies, these differences were more clearly perceived via the protein profiles. Considering that Cavendish cultivar is the more resistant option to endure Foc presence in the field, the lipids and proteins related to this subgroup might have an important role in pathogen adaptation. This study reports a new application of MALDI-MS for the analysis of a banana pathogen with intraspecies classification ability. Graphical abstract MALDI-MS classified Foc isolates by aggressiveness level on banana revealing the additional influence of location and host cultivar on the expression of lipids and proteins.