A really interesting discussion of porcinis and fungi species

[DufferinShroomer]

This is fascinating. Some British scientists took a package of porcini mushrooms from a grocery store which contained 15 porcinis and they ran some DNA sequencing on all 15. They found that 3 of the porcinis returned a DNA sequence that had never been recorded or identified - in other words they were new species to science! The research was reported in this CBC news item:

http://www.cbc.ca/news/technology/new-mushroom-species-discovered-in-london-grocery-store-1.2774326

The news article doesnt go into much depth but here is a slightly more in depth doscussion of the findings in an audio file:

http://thumbnails.cbc.ca/maven_legacy/thumbnails/14/561/abhomestretch_20140918_29877_uploaded.mp3

And finally here is a link to the research paper:

https://peerj.com/articles/570/

I see a number of take-aways from all the information in this package.

-Chinese exported porcini are probably not B. edulis at all but rather B. aereus. The Chinese have quite a reputation for shipping stuff that maybe isnt what it appears to be and this might be another example of that. If you want to eat B. edulis dont buy Chinese dried mushrooms because there is a decent chance B. edulis isnt what you will get.

-If finding new species of mushrooms interests you then the place to look might well be the grocery store rather than the forest.

-When you buy a package of mushrooms from the store no one can tell you with any sort of certainty what the you are buying. The same really would have to be true for mushrooms that you collect from the forests.

-It seems likely that trying to identify fungi species through DNA analysis may be totally futile because fungi can mutate faster than the mycologists can ever identify the mutant species through DNA analysis. I have always been fascinated with the common fungus known as apple scab. Apple scab attacks apple trees and of more interest the apple fruit rendering it too ugly to be marketable. Orchardists fight this fungus by spraying orchards with fungicide and some of these sprays are pretty effective in killing the fungus, sort of. The problem is that no spray can kill every last scrap of the fungus and some of it will survive, and the stuff that does survive is bits that are genetically resistant to the fungicide. This resistant strain then proceeds to multiply and attacks the trees and fruit again. The practical issue here is that spraying the orchard with the same fungicide is ineffective because the now dominant strain of the scab fungus is resistant to that fungicide. In practical terms the orchardist can get away with using the same fungicide in maybe 3 sprays then he has to change fungicides or concoct a soup of multiple fungicides to protect his crop. Over the years orchardists have burned through an astounding number of different fungicides and presumably they have created an astounding number of strains of apple scab, each different than its predecessor. The fungus is of course still called apple scab, it just isnt the same apple scab. Im not convinced that the DNA guys can ever keep up with the way mushrooms can mutate their DNA.

-Some of these previously unnoticed DNA variations may or may not explain why a mushroom like Tricholoma equestre can be quite poisonous in Europe but maybe not so much in North America. The big worry of course is will we find a morel species with a DNA variation that suddenly starts killing folks. This may already be happening with for example the orange capped Leccinum.

[Tasso]

Thanks for the links. Very interesting.

[John Smalldridge]

This does not seem to be a case of mutation as you describe it in apple scab, but rather human enhanced natural selection. The example given is that some of the apple scab did not succumb to the fungicide because of genetics that made it immune to the fungicide. I would guess that most wild mushrooms would not have to deal with this forced natural selection process. What is mind boggling to me is the sheer number of similar looking mushroom species and also how many are still yet to be discovered.

[ladyflyfsh]

The guy who bought this package of mushrooms with his wife, is Bryn Dentinger. He is now the head of mycology at Kew Botanical Garden in UK. He is the same person who did the dna sequencing on my Montana Boletus edulis for David Arora a few years back when he was still at U of O in Eugene.

[Dave W]

It would be no surprise to me if many species were eventually found to be grouped under the name "Boletus edulis." Here in PA/NY I have collected what seem to be 4 or 5 different types King Bolete (= porcini).

To my knowledge, the name "porcini" does not necessarily refer to an actual identifiable food product. In the marketplace, the name simply means "some type of edible mushroom which has pores." It seems that consumers have probably learned a few things about what actual porcini should taste like. Years back, I recall seeing what appeared to be dried Suillus species being marketed as porcini.