Diaporthe Diversity and Pathogenicity Revealed from a Broad Survey of Soybean Stem Blight in China.

Many species in the fungal (anamorph ) genus have become a group of the most important pathogens that cause seed decay, stem and pot blight, and stem canker in soybean production worldwide, resulting in significant yield loss. Due to increased disease prevalence but a lack of research, we performed an extensive field survey to isolate and identify the species associated with soybean stem blight in six provinces of China between 2019 and 2020. A total of 92 isolates were identified based on morphological and multilocus phylogenetic analysis and classified into six species: , , , , , and an unknown sp. The most frequently identified species was with 57 isolates. High genetic diversity was observed for the isolates, and haplotype network analysis revealed a mixed structure among the population in the six provinces. In comparative pathogenicity assays, different virulence levels were observed among the 92 isolates. The results of this study provide new insights into the spp. associated with soybean stem blight in China and can help in the development of effective management strategies.