Identification of a pathogen causing fruiting body rot of Sanghuangporus vaninii

Sanghuangporus vaninii is a medicinal macrofungus that is increasingly cultivated in China. During cultivation, it was found that the fruiting body of S. vaninii was susceptible to pathogenic fungi, resulting in significant economic losses to the industry. The symptoms of the disease occur in the initial stage of fruiting body development. The isolate YZB-1 was obtained from the junction of the diseased and healthy areas of the fruiting body. In order to verify the pathogenicity of YZB-1, its purified spore suspension was inoculated into the exposed area nearby the developing fruiting body of S. vaninii. After 10 days, the same disease symptoms appeared in the inoculated area. Morphological identification and molecular analysis of rDNA ITS region confirmed that the isolate YZB-1 was identified as Trichoderma virens. The temperature stability assay revealed that the mycelia of YZB-1 grew the fastest at 25 °C, with growth slowing down gradually as the temperature increased or decreased. Dual-culture tests of T. virens and S. vaninii showed that the inhibition rate of T. virens on S. vaninii mycelium was the highest (79.01 ± 2.79%) at 25 °C, and more green spores were produced at the intersection of T. virens and S. vaninii.