Species clarification of the prize medicinal Ganoderma mushroom Lingzhi

摘要

Lingzhi is a mushroom that has been renowned in China for more than 2,000 years because of its claimed medicinal properties plus its symbolic fortune. Lingzhi has high economic value mostly as a dietary supplement in the modern market especially in East Asia, and its medicinal functions have become a hot study topic. For over a century, the highly prized medicinal fungus, known as Lingzhi in East Asia, has been assigned to Ganoderma lucidum, a species originally described from Europe. Molecular studies in recent years have revealed that the commercially cultivated 'G. lucidum' (Lingzhi) in East Asia is a different species from the true G. lucidum. The present study aims to clarify the species identity of Lingzhi based on morphological studies and analysis of rDNA nuc-ITS sequences, and additional gene fragments of mt-SSU, RPB1, RPB2, and TEF1-α of Lingzhi were provided. All Ganoderma species that mostly resemble Lingzhi in phylogeny and /or morphology were included for analysis. We propose a new species G. lingzhi for Lingzhi, which has an East Asia distribution. The most striking characteristics which differentiate G. lingzhi from G. lucidum are the presence of melanoid bands in the context, a yellow pore surface and thick dissepiments (80-120 μm) at maturity. G. curtisii is most closely related to G. lingzhi in phylogeny and is from North America. Ganoderma flexipes, G. multipileum, G. sichuanense, G. tropicum and 'G. tsugae', are also closely related with G. lingzhi and are reported from China. These species are compared and discussed. 'Ganoderma tsuage' reported from China is determined as conspecific with G. lucidum, hence the distribution of G. lucidum extends from Europe to northeastern China.