''Ganoderma orbiforme'' most commonly known as ''G. boninense'' or just ''Ganoderma'' in oil palm pathology is a species of

polypore Polypores, also called bracket or shelf fungi, are a morphological group of basidiomycete-like gilled mushrooms and hydnoid fungi that form large fruiting bodies called conks, which are typically woody, circular, shelf- or bracket-shaped, ...

fungus that is widespread across southeast Asia. It is a

plant pathogen Plant diseases are diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like orga ...

that causes basal stem rot, a disease of the

African oil palm ''Elaeis guineensis'' is a species of palm commonly just called oil palm but also sometimes African oil palm or macaw-fat. The first Western person to describe it and bring back seeds was the French naturalist Michel Adanson. Jean-Marie Pelt, « ...

(''Elaeis guineensis''). The fungus was first described scientifically in 1838 by

Elias Magnus Fries Elias Magnus Fries (15 August 1794 – 8 February 1878) was a Swedish mycologist and botanist. He is sometimes called the Mycology, "Linnaeus of Mycology". In his works he described and assigned botanical names to hundreds of fungus and li ...

from collections made in

Guinea Guinea, officially the Republic of Guinea, is a coastal country in West Africa. It borders the Atlantic Ocean to the west, Guinea-Bissau to the northwest, Senegal to the north, Mali to the northeast, Côte d'Ivoire to the southeast, and Sier ...

Leif Ryvarden Leif Randulff Ryvarden (born 9 August 1935) is a Norwegian mycologist. Early life and education Leif Ryvarden was born in Bergen as a son of Einar Norberg Johansen (1900–1959) and Hjørdis Randulff (1912–1975). He finished his secondary ed ...

transferred it to the genus ''

Ganoderma ''Ganoderma'' is a genus of polypore fungi in the family Ganodermataceae that includes about 80 species, many from tropical regions. They may be called ''shelf mushrooms'' or bracket fungi and have a high genetic diversity. ''Ganoderma'' can b ...

'' in 2000. In addition to its type locality, the fungus has also been collected from the

Bonin Islands The Bonin Islands, also known as the , is a list of islands of Japan, Japanese archipelago of over 30 subtropical and Island#Tropical islands, tropical islands located around SSE of Tokyo and northwest of Guam. The group as a whole has a total ...

in the Pacific, and from Venezuela and Puerto Rico.

Transmission

''G. orbiforme'' is not a

soil borne pathogen A soil borne pathogen is a disease-causing agent which lives both in soil and in a plant host, and which will tend to infect undiseased plants which are grown in that soil. Common soil borne pathogens include ''Fusarium'', '' Pythium'', '' Rhizocto ...

, meaning it does not grow in soil and does not infiltrate from soil and into the root system. It is however also not killed by soil, and will reside in dead, buried palm trunk material. This has especially been observed when ''

Oryctes rhinoceros ''Oryctes rhinoceros'', also known as coconut rhinoceros beetle, Asiatic rhinoceros beetle, and coconut palm rhinoceros beetle, is a large species of beetle (typically 4–5 cm long), belonging to the rhinoceros beetles subfamily Dynastinae. ''O ...

''-infested material was buried.

Infection

''G. orbiforme'' has a hemibiotrophic lifestyle in ''E. guineensis''. During an invasion, ''E. guineensis'' roots stockpile

salicylic acid Salicylic acid is an organic compound with the formula HOC6H4COOH. A colorless (or white), bitter-tasting solid, it is a precursor to and a active metabolite, metabolite of acetylsalicylic acid (aspirin). It is a plant hormone, and has been lis ...

, which is a signal to downregulate its own expression of ascorbate oxidase and ascorbate peroxidase. AO and AP are reactive oxygen species scavengers, and so the total effect is to increase

ROS Ros or ROS or RoS may refer to: Organizations * Raggruppamento Operativo Speciale, the Anti-organized Crime Branch of the Italian Carabinieri * Registers of Scotland, a Scottish authority responsible for compiling and maintaining records * Repart ...

production. This entire pathway was found by Ho ''et al.'', 2016. Increased ROS is effective against hemibiotrophs but counterproductive against necrotrophs.

Genetics

Microsatellite A microsatellite is a tract of repetitive DNA in which certain Sequence motif, DNA motifs (ranging in length from one to six or more base pairs) are repeated, typically 5–50 times. Microsatellites occur at thousands of locations within an organ ...

markers have been developed to help identify the fungus and study the

genetic diversity Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species. It ranges widely, from the number of species to differences within species, and can be correlated to the span of survival for a species. It is d ...

of ''G. orbiforme''.

Research

Water agar is usable for isolation of this fungus, and is the simplest and cheapest.

CABI CABI (in various spellings) is an abbreviation that may refer to: * Centre for Agriculture and Bioscience International (CABI, sometimes also referred to as CAB International), a UK-based nonprofit inter-governmental organisation for scientific res ...

provides research and

technique Technique or techniques may refer to: Music * The Techniques, a Jamaican rocksteady vocal group of the 1960s * Technique (band), a British female synth pop band in the 1990s * ''Technique'' (album), by New Order, 1989 * ''Techniques'' (album), by ...

information for lab work with this pathogen.

References

External links

* * {{Taxonbar, from=Q5521450 Fungi described in 1838 Fungi of Africa Fungi of Asia Fungi of South America Fungal plant pathogens and diseases orbiforme Taxa named by Elias Magnus Fries Pests of oil palm Fungus species