A Biological Comparison of Three Species Associated with Alfalfa Anthracnose in Northern China.

Anthracnose caused by various species of is one of the most prevalent diseases in alfalfa worldwide that not only reduces forage yields but also severely compromises forage quality. A comprehensive survey was conducted in 2020 in the main production regions of northern China. The survey results showed that alfalfa anthracnose is prevalent in northern China, with the disease incidence ranging from 9% to 45% and the disease index from 5 to 17 (maximum possible score: 100). In total, 24 isolates were collected and identified as three species (, and ) based on morphological characteristics and phylogenetic analysis (combined sequences , , and ). The three species displayed remarkable environmental adaptability, exhibiting a capacity for growth, sporulation and conidial germination in temperatures ranging from 4 to 35 °C and in different nutrient conditions. Pathogenicity assays showed that was more virulent than the other two species, although the growth vigor (in terms of colony diameter, sporulation and conidial germination) of was the greatest.