Intraspecific antagonism means a disharmonious or antagonistic interaction between two

individual An individual is that which exists as a distinct entity. Individuality (or self-hood) is the state or quality of being an individual; particularly (in the case of humans) of being a person unique from other people and possessing one's own need ...

s of the same

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

. As such, it could be a

sociological Sociology is a social science that focuses on society, human social behavior, patterns of social relationships, social interaction, and aspects of culture associated with everyday life. It uses various methods of empirical investigation and ...

term, but was actually coined by

Alan Rayner Alan Rayner (born 1950) is a British biologist and educator. Biography Rayner was born in Nairobi, Kenya, as the youngest of two children. His mother was the Deputy Mayor of Nairobi and his father was a Plant Pathologist, working on coffee rust ...

and Norman Todd working at

Exeter University , mottoeng = "We Follow the Light" , established = 1838 - St Luke's College1855 - Exeter School of Art1863 - Exeter School of Science 1955 - University of Exeter (received royal charter) , type = Public ...

in the late 1970s, to characterise a particular kind of zone line formed between wood-rotting fungal

mycelia Mycelium (plural mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Fungal colonies composed of mycelium are found in and on soil and many other substrates. A typical single spore germinates in ...

. Intraspecific antagonism is one of the expressions of a phenomenon known as vegetative or somatic incompatibility.

Fungal individualism

Zone lines form in

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...

for many reasons, including host reactions against

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

encroachment, and inter-specific interactions, but the lines observed by Rayner and Todd when transversely-cut sections of brown-rotted birch tree trunk or branch were incubated in plastic bags appeared to be due to a reaction between different individuals of the same species of

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately fr ...

. This was a startling inference at a time when the prevailing orthodoxy within the

mycological Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans, including as a source for tinder, traditional medicine, food, and entheogens, ...

community was that of the "unit mycelium". This was the theory that when two different individuals of the same species of

basidiomycete Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Bas ...

wood rotting fungi grew and met within the substratum, they fused, cooperated, and shared nuclei freely. Rayner and Todd's insight was that basidiomycete fungi individuals do, in most "adult" or dikaryotic cases anyway, retain their individuality. A small stable of postgraduate and postdoctoral students helped elucidate the mechanisms underlying these intermycelial interactions, at

(Todd) and the

University of Bath (Virgil, Georgics II) , mottoeng = Learn the culture proper to each after its kind , established = 1886 (Merchant Venturers Technical College) 1960 (Bristol College of Science and Technology) 1966 (Bath University of Technology) 1971 (univ ...

(Rayner), over the next few years.

Applications of intraspecific antagonism

Although the attribution of individual status to the mycelia confined by intraspecific zone lines is a comparatively new idea, zone lines themselves have been known since time immemorial. The term

spalting Spalting is any form of wood coloration caused by fungi. Although primarily found in dead trees, spalting can also occur in living trees under stress. Although spalting can cause weight loss and strength loss in the wood, the unique coloration and ...

is applied by woodworkers to wood showing strongly-figured zone lines, particularly those cases where the area of "no-man's land" between two antagonistic conspecific mycelia is colonised by another species of fungus.

Dematiaceous “Black yeasts”, sometimes also black fungi, dematiaceous fungi, microcolonial fungi or meristematic fungi is a diverse group of slow-growing microfungi which reproduce mostly asexually (fungi imperfecti). Only few genera reproduce by budding ...

hyphomycetes, with their dark-coloured mycelia, produce particularly attractive black zone lines when they colonise the areas occupied by two antagonistic basidiomycete individuals. Spalted wood can be difficult to work, since different individual wood-rotting fungi have different decay efficiencies, and thus produce zones of different softness, and the zone lines themselves are usually unrotted and hard. Instraspecific antagonism can also sometimes be of assistance in quickly recognising the membership of clones in those fungi, particularly root-rots such as Armillarea where individual mycelia may colonise large areas, or more than one tree. It is even the subject of a recent paten

References

{{Reflist, colwidth=30em, refs= {{cite journal , author=Worral, J.J. , year=1997 , title=Somatic incompatibility in Basidiomycetes , journal=Mycologia , volume=89 , issue=1 , pages=24–36 , doi= 10.2307/3761169, jstor=3761169 {{cite book , author=Burnett J.H. , title=Fundamentals of Mycology , publisher=Arnold Publishers , location=London , year=1976 {{cite journal , author1=Rayner, A D M , author2=Todd, N K , year=1977 , title=Intraspecific antagonism in natural populations of wood-decaying basidiomycetes , journal=J. Gen. Microbiol. , volume=103 , pages=85–90 , doi= 10.1099/00221287-103-1-85, doi-access=free {{cite journal , author1=Rayner, A D M , author2=Todd, N K , year=1979 , title=Population and community structure and dynamics of fungi in decaying wood , journal=Advances in Botanical Research , volume=7 , pages=333–420 , doi= 10.1016/s0065-2296(08)60090-7, isbn=9780120059072 Mycology Fungal morphology and anatomy Wood