Accès membres

Mot de passe perdu? S'inscrire

04-01-2024 12:44

B Shelbourne B Shelbourne

I think this could be in the Mollisia olivaceocine

04-01-2024 21:20

Elisabeth Stöckli

Bonsoir,Apothécies de 0.25 – 0.6mm de diamètre

04-01-2024 13:02

Karen Poulsen

Hi, I found a few in two groups on lepus dropping

02-01-2024 22:36

Karen Poulsen

Hello there, Happy new Year! I found these small

27-07-2008 16:17

Jean-Louis CHEYPE Jean-Louis CHEYPE

Bonjour à tous Je sèche sur une minuscule (diam

24-12-2023 09:08

Michel Hairaud Michel Hairaud

Bonjour ,  I would thank anyone for help in the

02-01-2024 18:41

Koszka Attila

Hello all! I don't even get to the genus with thi

01-01-2024 14:07

éric ROMERO éric ROMERO

Bonjour, Sur excréments de chevreuil mis en boî

14-11-2023 14:16

Di Napier

Updated with id: Erysiphe prunastri. While lookin

27-12-2023 16:24

Robin Isaksson Robin Isaksson

Found in nothen Sweden, Jämtland on wood beside m

« < 40 41 42 43 44 > »
Mollisia/Mollisiaceae sp.
B Shelbourne, 04-01-2024 12:44
B ShelbourneI think this could be in the Mollisia olivaceocinerea group but I'm not sure how to separate the teleomorphs of the three species M. oblonga, M. nodosa, and M. mallochii. Also, the OCI seems quite variable or hard to interpret with no experience, and there are some similarities to M. cinerea group. Any feedback is appreciated.

The genus/family seems to be another tricky one. I have tried to use an unpublished key by A. Gminder (hard to get a good match), a (more recent one) by I. Wagner, and comparison with some of the examples in the 'Mollisia on wood & bark' folder in the drive of H.O. Baral.

Preparation: Kept on wood in the fridge for several days. Slides prepared from three ascomata in the same cluster, mounted in tap water unless otherwise mentioned. My first attempt at staining/reactions, ~1% IKI (5% diluted ~1:5 with tap water) allowing a drop to pass under the cover slip of a water mount, and 3% KOH mounted directly.

Habitat: Collected around one week ago (December), on hygric (almost saturated) unidentified deciduous wood, decorticated parts, in a pile of logs, mixed deciduous woodland, southern England. With teleomorphs of Calycina cf. citrina, Lachnum impudicum, Orbilia eucalypti, and Trichoderma strictipile on same wood pile. Some trebouxoid algae and helicoid conidia (seem different to M. nodosa microsclerotia) found around base of an ascoma.

Ascomata: Apothecial, discoid, initially cupulate to urceolate, then +/- patelliform with thin rim, eventually often plane, mostly not very lobate in maturity, pale grey to whitish margin, darker grey interior, brownish exterior lighter towards margin and smooth, overmature more pale and margin less defined, <= ~1mm diameter, sessile, gregarious and some crowded.

Reactions:
• IKI: apical rings bb 2?, cytoplasm of some asci going red-brown (depending on vitality?), cytoplasm of spores and paraphyses yellow.
• KOH: asci and paraphyses -, ectal excipulum greenish/olivaceous.

Subhymenium: Hyaline, densely woven hyphae.

Ectal excipulum: Textura globose to angularis, except at margin globose to more isodiametric and hyphoid, some cells with a central guttule visible, marginal apical cells mildly clavate and protruding, brown up to margin, darker (almost black) at base.

Marginal hairs: Cylindrical-clavate, plain, septate, (closer to hymenium some with longer irregular/asymmetric lanceolate apices?).

Asci: Cylindrical to mildly clavate, 8-spored, croziers +.

Paraphyses: Cylindrical-filiform, gradually slightly enlarged towards apex, large yellowish VBs, terminal cell longer ~2-3x, some branching identified, a few with crystals/exudate outside in IKI after squashing but may be unnatural.

Spores: Narrowly-ellipsoid to allantoid (average q-value), inequilateral and occasionally slightly curved in side view, aseptate, multi-guttulate, often lots of small guttules and several slightly larger ones, guttules not restricted to poles, OCI (0.5?) 1 – 2 (3?), larger guttules shadowy?, greater range of lengths (one extreme spore ~15 µm long not included), measured
(7.5) 8.3 - 10.7 (12.1) × (2.2) 2.5 - 3.05 (3.1) µm,
Q = (2.8) 2.9 - 4.1 (4.2); N = 25;
Me = 9.4 × 2.8 µm, Qe = 3.4.

Subiculum: Maybe anchoring hyphae seen in macrophotos but not identified in slides.

Anamorph: No linked structures identified.
  • message #77815
  • message #77815
  • message #77815
  • message #77815
  • message #77815
  • message #77815
  • message #77815
Hans-Otto Baral, 04-01-2024 17:26
Hans-Otto Baral
Re : Mollisia/Mollisiaceae sp.
Clearly a Mollisia based on the VBs in the paraphyses visible on your unstained photos.

The CI is surely max. 1, you must study living spores, or some in KOH. On the apper of your middle collage it is best visible.

Did you put a portion of the fingus straight in KOH and look directly under the Bino? The yellow reaction is inly visible for some seconds.

But it maybe that the KOH reaction was actually negatve.

I fear without DNA these fungi are difficult to identify. The conidia possibly do not belong to the Mollisia.
Ingo Wagner, 04-01-2024 18:13
Ingo Wagner
Re : Mollisia/Mollisiaceae sp.
Hello B Shelbourne!
[quote]
I think this could be in the Mollisia olivaceocinerea group but I'm not sure how to separate the teleomorphs of the three species M. oblonga, M. nodosa, and M. mallochii.
[/quote]
There is no answer to that yet.

I don't think your find belongs to Mollisia olivaceocinerea (mallochii, nodosa, oblonga).
The spore shape is wrong.
The spores of Mollisia olivaceocinerea look in side view like a bread.

[quote]
Also, the OCI seems quite variable or hard to interpret with no experience,....
[/quote]
The OCI-evaluation is a big problem when the spores are tiny.
The best way to examine Mollisia is in a fresh vital stage, ideally when the asci shoot their spores.
In age it is possible, that the destruction of spore-vacuoles looks like oil. 
Maybe you can examine the spores in Congo Red SDS? Drops of oil should remain there.

[quote]
• KOH: asci and paraphyses -,
[/quote]
No photo?

I have a collection that would fit microscopically, but macroscopically it looks different.
Has no official name or sequence, and is not in the key:
https://asco-sonneberg.de/pages/gallery/mollisia-clavispora-cf-230205-tr-iw195-01xsmjj42416.php?group_id=42416&position=87

Greetings
Ingo

B Shelbourne, 04-01-2024 21:59
B Shelbourne
Re : Mollisia/Mollisiaceae sp.
Thank you both very much for looking and your helpful suggestions.

It seems like it could be hard for me to resolve this on morphology. I certainly struggled to find a species in the keys that was a good match for both the spore size and other characters.


KOH reaction:
The last collage and the attached are all mounted in 3% KOH, but I can't be certain about a yellow reaction coming out in the mounting medium if it is only for a few seconds.


I still have some material so I can try the KOH again and (separately) the Congo red for the spores.


I was concerned about the vitality for the finer details of the asci and spores, it's a pity and I will consider this in future (and collecting ejected spores). Perhaps the best approach to progress here will be trying to collect some more vital material to examine (or just resign myself to genus).

  • message #77821
Ingo Wagner, 04-01-2024 23:03
Ingo Wagner
Re : Mollisia/Mollisiaceae sp.
Hello!

It may well be that your species does not yet have a name.
This is really not rare.

To see the yellow reaction, I recommend 100x magnification.
https://asco-sonneberg.de/pages/gallery/mollisia-albogrisea-230507-diff-6nt-iw210-stma23048-dsm116342-mcol-04jj42177.php?group_id=42170&position=14

Greetings
Ingo

  • message #77822
B Shelbourne, 05-01-2024 12:03
B Shelbourne
Re : Mollisia/Mollisiaceae sp.
Thank again, that example of the KOH reaction is very helpful.

I tried the KOH again and there was no noticeable yellowing of the medium, the first photo is 150x and this appearance didn't change (I watched it at 100x).

I have also included some more photos of spores but focusing on the contents is certainly a challenge (I think getting a spore print will make this much easier). It seems there are 1 - 3 (4) smallish guttules, often towards the poles, and so far I would judge the OCI to be something like 0.5 - 1.

The CR (right side of photos) was also helpful but I need to practise using it as I didnt manage to get an even stain or clean it very well.
  • message #77826
  • message #77826