UKTC Archive

RE: Ganoderma applanatum/australe on n.maple - implications

Subject: RE: Ganoderma applanatum/australe on n.maple - implications
From: Viper Snake
Date: Dec 27 2011 19:11:14

Dear David,
To conclude our exchange of view points on the subject, the following final 
information on "panic fruiting".

A) The phenomena of "dying with the tree" and "panic fruiting" could, I 
think, be explained in various ways, and so there seems to be an need for 
detailed research. Panic fruiting can either be prolific when there's still 
enough wood left to facilitate the massive fruiting with lots of or some 
extremely big fruitbodies or very poorly with just a few and/or small 
fruitbodies when the cellulose resources runs out.  

A) In my experience, there are three (to four) types of panic fruiting 
macrofungi :
- Obligate (biotrophic) parasitic macrofungi (for the last time) panic fruit 
before the tree dies ("death spasmes") or has (almost) succeeded in 
compartmentalisation of or closing in the mycelium and eliminating further 
growth of hyphae invading living tissues.
- Necrotrophic parasitic macrofungi panic fruit with fewer or much smaller 
fruitbodies when they run out of sugars to produce normal sized fertile 
fruitbodies from. Perennial bracket fungi develop ever poorer retracting tube 
layers "on top of" the layer developed the year before. Sometimes species 
such as Ganoderma lipsiense in this phase "recycle" the sterile inside 
tissues (trama) to form new layers from, as a result of which very big 
fruitbodies become ultra light weight and almost completely hollow.
- Necrotrophic parasitic macrofungi with a dual strategy of colonising living 
tissues and/or dead wood (rhizomorphs and spores), such as parasitic 
Armillaria species, when forced to produce fruitbodies once the tree dies or 
is felled and just a stump remains, panic fruit with massive numbers of big 
fruitbodies, because of the need of dispersion of spores over long distance 
when the energy source is lost, as rhizomorphs only can infect and colonise 
other trees/substrates over short distance.
- Saprotrophic macrofungi panic fruit just before the cellulose to produce 
fruitbodies from runs out. Species such as Daedalea quercina often panic 
fruit in the form of sterile lumps with a closed in catahymenium once they 
have completely brown rotted the heart wood of an oak and for the first time 
fruit on the tree.
And then there's the phenomenon of panic fruiting of the infected trees, 
which takes place just before, together with, or shortly after the panic 
fruiting of parasitic macrofungi and just before the tree dies in a final 
attempt ("death spasmes") to spread it's seeds, of which - contrary to a mast 
year, when about 70 % of the fruits are fertile - about 70 % is sterile.
And a final question : is Kretzschmaria deusta an exceptional case, because 
it starts out from the heart wood as a saprotroph, changes to a parasitic 
mode once the mycelium has invaded the cambium and returns to being a 
saprotroph once the tree has died ?
And now I shut up too.
Kind regards,
1) In your definition does this kind of fungus kill the living cells in the 
process of extracting it nutrients, like a necrotroph, or do they remain 
alive, like a biotroph?, or both, like a hemibiotroph?
1) Because trees affected by G. australe (normally) don't show symptoms of 
(bark or branch) necrosis or dieback (of parts) of the crown or foliage, like 
a biotroph.
2) Are you saying you have evidence that G. adspersum/australe can readily 
breach the reaction zone and/or boundary zone of functional xylem and then 
colonise that wood in a tree with good vitality?
2) Not evidence on a microscopical level in a living tree (yet), but assuming 
G. australe can, because of its (partially sterile) panic fruiting just 
before or shortly after the tree dies and not being able to produce 
(completely) fertile brackets from dead wood alone.

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