Ganoderma is a genus of polypore mushrooms that grow on wood, and include about 80 species, many from tropical regions. Because of their extensive use in traditional Asian medicines, and their potential in bioremediation, they are a very important genus economically. Ganoderma can be differentiated from other polypores because they have a double-walled basidiospore. They are popularly referred to as shelf mushrooms or bracket fungi.
Video Ganoderma
Etymology
The name Ganoderma is derived from the Greek ganos/????? "brightness, sheen", hence "shining" and derma/????? "skin". The genus Ganoderma was erected as a genus in 1881 by Karsten and included only one species, G. lucidum (Curtis) Karst . Previously, this taxon was characterized as Boletus lucidus Curtis (1781) and then Polyporus lucidus (Curtis) Fr. (1821) (Karsten 1881). The species P. lucidus was characterized by having a laccate pileus and stipe, and this is a character that Murrill suspects was the reason for Karsten's division because only one species was included, G. lucidum . Patouillard revised Karsten's genus Ganoderma to include all species with pigmented spores, adhering tubes and laccate crusted pilei, which resulted with a total of 48 species classified under the genus Ganoderma in his 1889 monograph. Until Murrill investigated Ganoderma in North America in 1902, previous work had focused solely on European species including, for example, G. lucidum, G. resinaceum Boud. (1890) and G. valesiacum Boud. (1895).
Maps Ganoderma
Description
Ganoderma are characterized by basidiocarps that are large, perennial, woody brackets also called "conks". They are lignicolous and leathery either with or without a stem. The fruit bodies typically grow in a fan-like or hoof-like form on the trunks of living or dead trees. They have double-walled, truncate spores with yellow to brown ornamented inner layers.
Phylogeny
The genus was named by Karsten in 1881. Members of the family Ganodermataceae were traditionally considered difficult to classify because of the lack of reliable morphological characteristics, the overabundance of synonyms, and the widespread misuse of names. Until recently, the genus was divided into two sections - Section Ganoderma with a shiny cap surface (like Ganoderma lucidum) and Elfvingia, with a dull cap surface, like Ganoderma applanatum.
Phylogenetic analysis using DNA sequence information have helped to clarify our understanding of the relationships amongst Ganoderma species. The genus may now be divided into six monophyletic groups:
With the rise of molecular phylogenies in the late 20th century, species concept hypotheses were tested to determine the relatedness amongst the nuanced morphological variabilities of the laccate Ganoderma taxa. In 1995, Moncalvo et al constructed a phylogeny of the rDNA, which was the universally accepted locus at that time, and found five major clades of the laccate species amongst the 29 isolates tested. It turned out that G. lucidum was not a monophyletic species, and further work needed to be done to clarify this taxonomic problem. Interestingly, they also found that G. resinaceum from Europe, and the North American 'G. lucdium', which Adaskaveg and Gilbertson found to be biologically compatible in vitro, did not cluster together. Moncalvo et al. reject biological species complexes as a sole tool to distinguish a taxon, and suggested using a combination between biological and phylogenetic species concepts to define unique Ganoderma taxa.
In 1905, American mycologist William Murrill delineated the genus Tomophagus to accommodate the single species G. colossus (then known as Polyporus colossus) which had distinctive morphological features that did not fit in with the other species. Historically, however, Tomophagus has generally been regarded as a synonym for Ganoderma. Nearly a century later, phylogenetic analyses vindicated Murrill's original placement, as it has shown to be a taxonomically distinct appropriate genus.
Significance
Industry
Ganoderma are wood-decaying fungi with a cosmopolitan distribution. They can grow on both coniferous and hardwood species. They are white-rot fungi with enzymes that allow them to break down wood components such as lignin and cellulose. There has been significant research interest in trying to harness the power of these wood-degrading enzymes for industrial applications such as biopulping or bioremediation.
Bioactive compounds
For centuries, laccate (varnished or polished) Ganoderma species have been used as traditional medicine in many parts of Asia. These species are often mislabeled as 'G. lucidum', although genetic testing has shown this to be multiple species such as G. lingzhi, G. multipileum, and G. sichuanense . Several species of Ganoderma contain many bioactive compounds (~400), such as triterpenoids and polysaccharides, which are likely the primary medicinal compounds. Collectively, the Ganoderma species are being investigated for a variety of potential therapeutic benefits:
Notable species
- Ganoderma applanatum - Also known as the Artist's Conk. An infestation of this species was the main factor in the loss of the Anne Frank Tree.
- Ganoderma lucidum - Also known as Reishi or Lingzhi. A very valuable medicine in Asian herbal medicine, known as the "King of Herbs".
- Ganoderma multipileum - A genomic study in 2009 discovered that populations of G. lucidum in Tropical Asia are actually a separate species.
- Ganoderma philippii - A plant pathogen.
- Ganoderma pseudoferreum - Responsible for the root rot of cacao, coffee, rubber and tea trees.
- Ganoderma tsugae - A polypore which grows on conifers, especially hemlock; thus the common name, Hemlock varnish shelf. Similar in appearance to Ganoderma lucidum, which typically grows on hardwoods.
References
Source of the article : Wikipedia
0 Comments