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21-04-2026 13:36

Gernot Friebes

Hi,I am out of ideas for this one. I collected Sal

21-04-2026 13:19

Gernot Friebes

Hi,this Lophodermium on Typha has ascospores measu

21-04-2026 13:05

Gernot Friebes

Hi,this hyphomycete feels familiar but I was not a

20-04-2026 22:00

Malcolm  Greaves Malcolm Greaves

These pale yellow, hairy ascos were growing on cul

19-04-2026 21:23

Steve Clements

Bonjour, I found this anamorphic fungus on old pl

19-04-2026 20:46

Steve Clements

1 mm diameter approx spherical conidiophores on pl

12-04-2026 17:56

Hardware Tony Hardware Tony

Found on dead stems in February earlier this year

17-04-2026 19:16

Enrique Rubio Enrique Rubio

Hi to everybodyI would appreciate any assistance r

14-04-2026 05:32

Ethan Crenson

Hi all, A few weeks back a friend pointed out som

17-04-2026 15:14

Bruno Coué Bruno Coué

Bonjour.Récoltes du 16/04/2026, sur feuilles mort

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DNA match
Malcolm Greaves, 27-01-2026 11:43
Malcolm  GreavesIs anyone with experience of DNA testing able to tell me if a 97% match to a know species is enough to justify giving it that name or is it likely to be a related but different species?
Thanks
Mal
Nicolas VAN VOOREN, 27-01-2026 11:52
Nicolas VAN VOOREN
Re : DNA match
Well, you cannot answer by yes or no to such a question. It depends of what type of sequence (locus) you compare, length of these sequences, quality of your sequence, etc.
In the best case, with 97% you can hypothesize this is a different 'species', but to be sure, you must generate a phylogeny and also evaluate the morphological differences.
Hans-Otto Baral, 27-01-2026 12:02
Hans-Otto Baral
Re : DNA match
Assuming that you have an ITS sequence, the idea of 97% similarity resp. 3% distance is antiquated. In some groups of fungi this works, in others you need to accept lower distances, such as 1.5-2%, and in some there is no difference at all in the ITS between species and you must use other regions. To evaluate an ITS distance you must search for ATCATTA and TGACCT in your sequence and only test the part between them. When you got the distance in GenBank Blast you must look how many gaps are among the differences, because these count less than nucleotide differences. What kind of fungus do you have?
Malcolm Greaves, 27-01-2026 12:59
Malcolm  Greaves
Re : DNA match
It was a Geoglossum which was a perfect fit microscopically for G pseudoumbratile. The DNA came back with a 97.1% match to umbratile.
The test was accompanied with the note
Your sample has been processed and analysed using DNA techniques. For this analysis,
the commonly used regions for DNA Barcodes of fungi, Domain 1 and Domain 2 of the large
ribosomal subunit (D1/D2 regions of LSU rDNA) have been sequenced. Sequencing results
have been locally aligned against the NCBI database
Unfortunately I don’t have much experience of this form of analysis.
Mal
Hans-Otto Baral, 27-01-2026 14:22
Hans-Otto Baral
Re : DNA match
LSU is much less variable, so 3% mean very much.  But you need to know which G. umbratile strain appeared. I see 4 in Genbank, one of which differs by 4% from the other 3.