Two new toxic yellow Inocybe species from China: morphological characteristics, phylogenetic analyses and toxin detection

Sai Nan Li1*, Fei Xu2*, Ming Jiang1, Feng Liu2, Fang Wu1,3, Ping Zhang1, Yu Guang Fan4, Zuo Hong Chen1

1 College of Life Sciences, Hunan Normal University, Changsha, Hunan 410006, China 2 Ningxia Center for Disease Control and Prevention, Yinchuan, Ningxia 750004, China 3 Hunan Edible Fungal Research Institute, Changsha, Hunan 410013, China 4 Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Haikou, Hainan 571199, China

Abstract
Some species of Inocybe s. str. caused neurotoxic poisoning after consumption around the world. However, there are a large number of species in this genus that have not been studied for their toxicity or toxin content. In this study, we report two new toxic yellow Inocybe s. str. species from China based on morphological characteristics, phylogenetic analyses and toxin detection. Among the two species, Inocybe squarrosolutea is reported as a newly recorded species of China. We also describe a new species, I. squarrosofulva, which is morphologically similar to I. squarrosolutea. The new species is characterized by its ochraceous squarrose pileus, distinctly annulate cortina on the stipe, nodulose basidiospores and thick-walled pleurocystidia. Muscarine in the fruitbodies was detected by UPLC–MS/MS, the content in I. squarrosolutea and I. squarrosofulva were 136.4 ± 25.4 to 1683.0 ± 313 mg/kg dry weight and 31.2 ± 5.8 to 101.8 ± 18.9 mg/kg dry weight, respectively.

Keywords
Inocybaceae, muscarine, taxonomy