Establishment of an Efficient High-yield Sporulation Protocol for <i>Mycocentrospora acerina</i> causing Leaf Blight of <i>Asarum heterotropoides</i> Fr. Schmidt var. <i>mandshuricum</i> (Maxim.) Kitag.

<i>Mycocentrospora acerina</i> is responsible for inducing severe leaf blight on <i>Asarum heterotropoides.</i> However, its poor sporulation under standard culture conditions significantly limits research on pathogenicity and disease management. This study aimed to develop an efficient high-yield and reproducible sporulation protocol by optimizing cultural conditions and nutritional factors. The results indicate that near-ultraviolet (Near-UV) light serves as a critical inducer of sporulation for <i>M. acerina</i>. In contrast to the standard culture on PDA medium at 20℃, where the pathogen fails to produce conidia, exposure to Near-UV light effectively stimulated sporulation, yielding a relatively robust production of 1.37×10³ conidia/mL after 21 days. Furthermore, V8 medium provided the optimal substrate conditions, yielding 4.56×10³ conidia/mL under the same cultural conditions after 14 days, a value significantly higher than those on other tested media. The optimized protocol (Near-UV light, V8 medium, 20℃, pH 7.0, 1 g/L glucose, and 1 g/L potassium nitrate) achieved a conidial yield of 1.0×10⁵ conidia/mL after 14 days. The conidia produced using the optimized sporulation protocol were morphologically identical to wild-type conidia and exhibited similar germination and pathogenicity. This established sporulation protocol provides vital materials for further studies, including infection, pathogenicity mechanism, and host-pathogen interaction dynamics and lays a theoretical basis for developing targeted strategies to control <i>A. heterotropoides</i> leaf blight.