First report of crown and foot rot on durum wheat caused by Fusarium algeriense in Europe

Crown and Root Rot (FCR; FRR) is an economically important disease on durum wheat (Triticum turgidum ssp. durum) in Italy, particularly in the Mediterranean region. Several fungi may cause FCR or FRR leading to significant yield and quality losses. The most common causal agent in Italy is Fusarium culmorum (W.G. Smith). During an extensive survey on fields affected by FCR or FRR in Southern Italy, in 2024, besides confirming the presence of F. culmorum and Fusarium pseudograminearum, Fusarium-like colonies were also isolated from symptomatic plants sampled in 4 regions: Apulia, Basilicata, Campania and Sicily. After 6 days of incubation at 25°C, the developing colonies were removed, and single-spore cultures were obtained. On PDA, the pigmentation varied from light orange to yellowish-white. Morphological characteristics observed under microscope matched the first description of Fusarium algeriense made by Laraba et al. (2017). Sequence analyses were performed for four genes (tef1-α, ITS, CaM, βT), showing high identity with sequences available in GenBank for the F. algeriense type strain, isolate NRRL 66647 (Laraba & O'Donnell): tef1-α showed 99.68–99.82% and ITS showed 99.81–100% identity. A pathogenicity assay was carried out in greenhouse conditions using the susceptible durum wheat cv Iride. The tested isolates of F. algeriense varied in virulence and generally proved weak pathogens, causing a disease index ranging from a 4.4% to 38.0% with an average of 15.0% compared to 100% scored for a highly virulent isolate of F. culmorum. F. algeriense was successfully reisolated from the symptomatic tissues of the inoculated seedlings, thereby fulfilling Koch’s postulates. To the best of our knowledge, this is the first report of FRR or FCR caused by F. algeriense in Europe.