Work

Identification and fungicide sensitivity of Monosporascus lespedezae sp. nov. causing root rot of Lespedeza davurica in Gansu, China

Year: 2026

Type: article

Abstract: Lespedeza davurica is an important leguminous forage species widely distributed in China’s natural grasslands, where it contributes significantly to ecological stability and sustainable animal husbandry. However, a severe root rot disease, with disease incidence up to 100% has been observed in surveyed areas of Huan County, Gansu Province, China, causing substantial damage to the host plant, while the causal agent remains uncharacterized. Four fungal isolates recovered from symptomatic roots were identified as a novel species of Monosporascus based on morphological characteristics and phylogenetic analyses of ITS, LSU, and Tub2 sequences. The isolates were formally described as Monosporascus lespedezae sp. nov. Pathogenicity tests confirmed high virulence, with inoculated plants showing 100% disease incidence and significant reductions in root length (81.3%) and plant height (63.0%) compared to non-inoculated controls ( P < 0.001). In vitro fungicide sensitivity assays showed differential responses among tested compounds: diniconazole exhibited the lowest EC 50 value (0.5198 μg/mL), whereas carbendazim completely inhibited mycelial growth at 10 μg/mL (EC 50 = 2.791 μg/mL). Both fungicides show promise for further valuation. This study represents the first report of M. lespedezae sp. nov. as a pathogen of L. davurica , establishes its taxonomic position, and provides baseline in vitro fungicide sensitivity data, thereby laying a scientific foundation for developing effective disease management strategies.

Source: Frontiers in Plant Science

DOI: 10.3389/fpls.2026.1869588