Characterization, Phylogenetic Analyses, and Pathogenicity of <i>Eutiarosporella dactylidis</i> on Sorghum in China

Sorghum, the fifth-largest cereal crop globally and a C4 crop, mainly grows in arid and semiarid areas. In 2021 to 2023, a new foliar disease of sorghum occurred in China. The diseased leaves showed water-soaked symptoms in the leaf tip and margins, resulting in half- and full-leaf desiccation and necrosis, thus affecting plant photosynthesis. A total of 24 <i>Eutiarosporella</i> strains were isolated from symptomatic leaves. Based on morphological characteristics, multilocus phylogenetic analysis involving <i>ITS</i>, <i>LSU</i>, and <i>EF1-α</i> sequences, and the pathogenicity test, the pathogen of sorghum causing leaf blight in China was identified as <i>Eutiarosporella dactylidis</i>. The virulence of all <i>E. dactylidis</i> strains was evaluated using the spray-mycelium method. Different strains showed significantly different pathogenicities toward a susceptible cultivar, Longza 10, with disease indexes ranging from 23.76 to 60.37. This study first reported leaf blight of sorghum caused by <i>E. dactylidis</i> and named it "Eutiarosporella leaf blight," which provides a theoretical basis for farmers in disease management.