Taxonomic Revision of the Japanese Tricholoma ustale and Closely Related Species Based on Molecular Phylogenetic and Morphological Data
- Author: mycolabadmin
- 2021-09-20
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Summary
This research revealed that what was thought to be a single poisonous mushroom species in Japan (Kakishimeji) is actually four different species. Only one of these species contains significant levels of the toxin that causes stomach problems. This discovery helps explain why people in some regions can eat these mushrooms safely while others get sick.
Impacts on everyday life:
– Improved food safety through better identification of poisonous mushrooms
– More accurate mushroom identification guides for foragers and consumers
– Better understanding of which specific mushroom species are safe to eat
– Reduced risk of mushroom poisoning through proper species identification
– Enhanced knowledge for mushroom cultivation and commercial use
Background
Kakishimeji, identified as Tricholoma ustale and belonging to Tricholoma sect. Genuina, is a common poisonous mushroom in Japan that contains the toxic compound ustalic acid and causes digestive issues. However, this fungus is consumed without problems in some regions of Japan, suggesting taxonomic confusion regarding the species complex.
Objective
To clarify the probable species complex of Kakishimeji through phylogenetic analysis and morphological characterization of specimens collected from various forest sites in Japan.
Results
Kakishimeji was found to consist of four distinct phylogenetic clades based on all DNA regions tested. Two clades included European T. stans and T. albobrunneum type specimens. The other two clades consisted of sister clades to T. pessundatum and T. ustaloides. All four phylogenetic clades had different spore and basidium sizes. The analysis led to the description of two new species: T. kakishimeji and T. kakishimejioides.
Conclusion
The study revealed that what was traditionally identified as T. ustale (Kakishimeji) in Japan actually comprises four distinct species, including two previously known species and two newly described species. True T. ustale was not found in Japan. The toxic compound ustalic acid was confirmed to be present in T. kakishimeji specimens but not in the other related species, explaining the variable reports of toxicity.
- Published in:Mycoscience,
- Study Type:Taxonomic Research,
- Source: 10.47371/mycosci.2021.06.002