Intraspecific antagonism

As such, it could be a sociological term, but was actually coined by Alan Rayner and Norman Todd working at Exeter University in the late 1970s, to characterise a particular kind of zone line formed between wood-rotting fungal mycelia.

This was the theory that when two different individuals of the same species of basidiomycete wood rotting fungi grew and met within the substratum, they fused, cooperated, and shared nuclei freely.

The term spalting 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 hyphomycetes, with their dark-coloured mycelia, produce particularly attractive black zone lines when they colonise the areas occupied by two antagonistic basidiomycete individuals.

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.