Subject: Growing morel mushrooms

From: [email-masked]
Date: 2 Oct 1994 21:07:39 -0500

> >
> >> I seem to remember reading a paper/abstract somewhere that some morels had 
> >>a symbiotic (mycorrhizal) relationship with various ferns and grasses.  If 
> >>true then surely this IS a scam of note.
> 
> I think I've seen reports for at least one type of tree, too.

I'm pretty sure that Morchella esculenta forms ectomycorrhizae on American
Elm, though I can't find where I read this (always misplacing references).
Alexopolous says about morels "many if not all are mycorrhial but this has
not been proved."  

> 
> >I don't think this is the case; if morels do engage in mycorrhizae, then 
> >its certainly not of the obligate kind.  The fact that Morels do so well 
> >in the wake of disturbance, especially forest fires, seems to rule aginst 
> >their being obligate mycorrhizal fungi.

Certainly, they are not obligate mycorrhizae, since it is possible to isolate
vegetative cultures of the fungus simply by plating a piece of the ascocarp
on media.

> 
>  Under these conditions they operate more like cryophiles- microbes
> which thrive best in very cold, nutrient rich soils, but are usually 
> outcompeted in warmer soils.  Whole forests used to be burnt down in Russia
> to encourage morels- a practice which surely would not have become popular
> if it was necessary to have mycorrhizae.

I have to disagree.  A stable mycorrhizal reationship should encourage
vegetative growth of the fungus.  Sex generally occurs when a nutrient
source becomes limited.  Burning forests would cause the nutrient
source of the fungi (the living tree) to be absent.  At this point, the 
organism puts all of its resources into sex, and long distance dispersal.

-enjoy.
A
--
David Maxwell
382 Russell Labs                          [email-masked]
1630 Linden Drive                         [email-masked]