Amanita sp-WI03

I. nrITS near identity in Amanita abliceps and A. sp-WI03
The nrITS sequences of the two proposed taxa are essentially identical.  So are their nrLSU sequences.  The latter are treated in the next block (numbered "II").  I have attached a picture showing a full alignment of four sequences from different samples of A. albiceps and seven sequences from different samples of A. sp-WI03.nbsp; Use your browser's "View Image" option to see a full screen display of the alignment.

The alignment has the SSU and LSU segments entirely trimmed away leaving 498 columns in the alignment.  As you will see, not all of the sequences are the same length.  They vary from 492-498 nucleotides long.  This is because there is a variable length "AT" repeat included in all the sequences.  A repeat of this sort can happen in nature, and it can happen during the PCR process.  It is not considered a meaningful difference between the sequences. The repeat occurs between and including columns 161-175 of the alignment.

On the left of the alignment are the names of the samples.

Little marks on the otherwise gray bars of the alignment indicate the following four variations in the alignment:

Coll. 11 has one C in a column of T's.  The difference happens to be from a sample of sp-WI03.

Coll. 252 has one Y (C or T ambiguity) in a column of T's.  The difference happens to be from a sample of sp-WI03.

Coll. 387 has one R (A or G ambiguity) in a column of G's.  The difference happens to be from a sample of A. albiceps.

Coll. 422 has one T in a column of C's.  The difference happens to be from a sample of A. albiceps.

If I were to draw a distinction it would have to be based on one variation in each of 4 columns.  The evidence involving ambiguites could (arguably) be discarded.  The sample size is not gigantic.  I would not judge there is significant support to separate species on the information I have provided here.

I should note that this is not an unusual occurrence for nrITS. There are a number of cases in which species that appear morpologically distinct are barely or not at all distinct according to the barcode. One resolution is to say that some species have albino basidiomes.  Another is to say, "Wait and see what some other genes will show." ....
Here is a sidelight to the story.  The three collections from Michigan (lines 1, 2, and 10 in the figure) were all made by Huafang Su.  They have a mixture of white and gray caps.  One cap of each color was collected by Huafang Su on the same day at the same site.  These collections are documented on mushroomobserver:

mushroomobserver.org/333841 - albiceps (white cap)
mushroomobserver.org/333839 - sp-WI03 (gray cap)

II. nrLSU near identity in Amanita abliceps and A. sp-WI03
Again, we report on an alignment of sequences drawn from collections of (a) A. albiceps (determined by presence of a purely white cap and conformance of the nrITS collection's nrITS sequence with nrITS sequences derived from Quebec material collected by Y. Lamoureux and identified by him as fitting his concept of A. albiceps and (b) the wholely or partially gray-capped material described on the present page as A. sp-WI03.

Again, the following description refers to a figure showing an alignment (immediately above).

In this case, the alignment begins with columns 1-15 containing the penetratrix-type nrLSU prefix (5' motif)—"TCTGACCTCAAATCA."  The sequences were trimmed to match the length of the shortest in the original set.  As a consequence the alignment is 1435 characters long.  It should be noted that at the last 450 or so characters are in a highly conserved region of the nrLSU gene, and variation in this region would be expected to be minimal.  In the present case, we report no variation therein.

In fact, the alignment reveals minimal variation overall.

Columns 113-116 include a variable length (3-4 characters) multi-"A" repeat.

Column 593 has a "Y" in row one, with all other rows having a "T."

Column 599 has a"T" in row two, while all other rows have a "C."