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|I’d Call It That||3.0||10.78||2||(Dave W)|
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You don’t want to store in high heat. The hot air hold more moisture. Heat and moisture are the enemies of DNA.
A curious side note…very far off to the side… I’m supplying a specimens to a fellow in British Columbia who is studying the variety of non-protein amino acids that occur in amanitas. This is motivated by the fact that the toxin of Amanita smithiana is thought to be such a substance. He’s finding a large number of such amino acids in amanitas, and the combination appears to differ from species to species. This comes up because they are destroyed by exposure to heat or moisture; and specimens not yielding DNA will yield these amino acids. People have looked at this substances in Amanita before (as far back as the 1960s); however, they haven’t tried to sample every one of Bas’ stirpes in sect. Lepidella (just as an example) to see what is going on across taxonomically broad swaths of the genus.
hopefully during morel season :-) I have the unit in an attic room, and it gets pretty hot there in the summer. So I’ll need to update my methods as the summer progresses.
I think that you would be very safe and effective if the interior of the dryer were to range from 110 to 120 degrees F in the active drying region. A chimney-like draft arrangement is critical, with cool air entering at the bottom and the hot air exiting at the top (don’t cover too many holes).
It’s good to know that at least some of the material I sent has yielded useful molecular data.
Now that I’m thinking of it… Rod, do you have a recommendation for temperature range inside a dehydration device? My homemade dryer has a plexiglass top with holes drilled to allow air to escape. I control interior temperature by covering/uncovering the holes.
We have obtained barcode and nrLSU (nuclear ribosomal large subunit) sequences from this material. Thank you very much for contributing this collection to our research. Several months back I reported that the flavorubescens sequences seemed to indicate that all the material from within the U.S. assigned to flavorubescens and sequenced in Dr. Hughes’ lab appeared to be a single species; and that is still true after tripling the number of collections sampled.
I used the top photograph on this observation as an additional illustration on the flavorubens page of WAO.
has some problems outside of the macro- realm:
It causes the basidia to be dominated by subnormal size spores. This is probably why I can’t confirm your spore measurements when I look at your dried material. That issue has puzzled me a bit in the past; now I see an explanation for it. There is an old paper by Dr. Leo Tanghe (in the WAO bibliography) in which he reports on taking spore print after spore print from the same specimen of A. bisporigera over many, many hours. He watched the size of the spore drop significantly as the fruiting body ran out of water. Also, the spores became rounder and rounder because width changes less than length under these circumstances. The latter was observed by E. J. H. Corner in his studies of coral fungi in the 1940s. There’s also a 1947(?) paper by Corner listed in the WAO bibliography, which, so far as I know, also includes the original idea for a sporograph.
It contributes to collapse of cell structure in the gills (particularly). This makes some taxa very hard to identify in detail because clamps become very hard to see and formerly inflated cells become very hard to reinflate for microscopic viewing.
And, there’s the DNA problem.
We are all living and learning, David.
Again, many thanks to you.
Thanks for the update. As I have said previously, one experiences a sense of involvement in something larger than oneself as a result of contributing to these studies and then learning about the results. For an amateur like myself, who had spent years collecting primarily edibles, this has added a whole new dimension to the hobby.
As for the drying techniques… I should pay more attention to getting material into and out of the the dryer in a timely fashion. I use a home-made dehydrator similar to the one I have seen you use at the large forays, sheet-metal bent into a column with two light bulbs wired in at the base. I’ve been using two 75 watt bulbs. I think maybe part of the problem is that I sometimes pre-dry material by hanging in a south-facing attic window. For preserving the integrity of macro-traits this seems to work very well. But I suppose that it’s not in the best interest of preserving molecular integrity. I’ll make adjustments.
This collection and eight others have been sequenced recently at the Univ. of Tennessee, Knoxville, under the direction of Dr. Karen S. Hughes. The sequences and a summary of results were received on the 1st of October while I was away from the office. The sequences come from material collected in Connecticut, Missouri, New Jersey, New Mexico, Ohio, and Pennsylvania. All this material was judged to be Amanita flavorubens prior to sequencing. All the sequences are in agreement. Hence, it would appear from this evidence that Amanita flavorubens as presently conceived in North America is likely to be a single species.
Some of your material has been producing DNA that is more difficult to sequence than other recent collections. I would guess that this may be because you are either drying top slowly or too quickly. Some heat is required (maybe 105-120 degrees F) is require to keep from losing DNA to moisture. Exceeding the above range of temperature can damage DNA due to too much heat.
Thank you for your contribution to our research.
Created: 2013-07-02 03:51:09 CEST (+0200)
Last modified: 2013-07-02 04:59:06 CEST (+0200)
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