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17-07-2024 22:37

Peter Welt Peter Welt

Who can help? Arx, J.A. von. 1973. Ostiolate and

16-07-2024 18:32

Andgelo Mombert Andgelo Mombert

Bonsoir, Un discomycète sur Liochlaena lanceolat

17-07-2024 16:29

Andgelo Mombert Andgelo Mombert

Hello,A colleague found an unknown fungus on the s

17-07-2024 10:53

Hans-Otto Baral Hans-Otto Baral

I have a question about the scaling of illustratio

17-07-2024 08:35

Peter Welt Peter Welt

Who can help? Malloch, D.; Hubart, J.-M. 1987. An

17-07-2024 11:33

Angel Pintos Angel Pintos

Hello, anybody body has:Pande A. and Rao, V.G. (1

11-01-2022 16:36

Jason Karakehian Jason Karakehian

Hi does anyone have a digital copy of Raitviir A (

24-08-2020 13:00

Yulia Lytvynenko Yulia Lytvynenko

Dear friends.Looking for a copy of the following w

11-07-2024 14:29

Viktorie Halasu Viktorie Halasu

Hello, a thin-fleshed Mollisia on a monocot stem

15-07-2024 10:38

Joaquin Martin

Hi, I found this Ascobolus in company of Cheilyme

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Dumontinia ulmariae ?
bernard BOUSQUET, 07-04-2009 11:16
Bonjour,

Tous les printemps, début avril, en prospectant la saligue du gave de Mauléon, au niveau de Tardets , je rencontre un petit asco en forme de coupe (0.5 à 1 cm de diamètre) dont le stipe se termine par un sclérote noir, faisant penser à Dumontinia tuberosa. En l’absence d’Anémones sylvie sur la station, je me demande si ce champignon ne serait pas Dumontinia ulmariae. Les spores, qui mesurent en majorité 12 (de 10 à rarement jusqu’à 15) sur 6-7.5 microns, semblent assez bien coller avec cette hypothèse.

Merci d’éclairer ma lanterne.

Bernard BOUSQUET
  • message #7382
bernard BOUSQUET, 07-04-2009 11:18
Re:Dumontinia ulmariae ?
photo des spores
  • message #7383
Hans-Otto Baral, 07-04-2009 11:21
Hans-Otto Baral
Re:Dumontinia ulmariae ?
dear Bernard

In my opinion, you should provide much larger spore photos to clarify your fungus. With oil immersion it is then usually possible to see the nuclei in the spores. Typical D. tuberosa has 4-nucleate spores, while Sclerotinia sclerotiorum has 2-nucleate spores. Perhaps also a macrophoto would help. I do not know D. filipendulae personally. Were the 8 spores all of the same size within the asci?

Zotto
bernard BOUSQUET, 07-04-2009 11:49
Re:Dumontinia ulmariae ?
Merci pour votre réponse rapide.
La majorité des spores observées sont biguttulées. est-ce un bon indice ?
BB
Hans-Otto Baral, 07-04-2009 12:09
Hans-Otto Baral
Re:Dumontinia ulmariae ?
The guttules (oil drops, LBs) are much more distinct than the nuclei. You need to look with oil immersion and to close a bit the aperture. Often helps vital staining with Lugol or Cresyl blue. But this is difficile because the spores may finally die, and then the nuclei are not further visible.

Zotto
  • message #7386
bernard BOUSQUET, 07-04-2009 15:16
Re:Dumontinia ulmariae ?
Désolé ! je ne dispose pas d'un matériel micro suffisamment performant pour voir ces détails.
Hans-Otto Baral, 07-04-2009 17:28
Hans-Otto Baral
Re:Dumontinia ulmariae ?
What is your equipment? To see this needs only a 100x oil immersion objective of medium quality, a 10x widefield ocular and living material.

Zotto
Michel Hairaud, 11-04-2009 18:41
Michel Hairaud
Re:Dumontinia ulmariae ?
Bonjour Bernard et Zotto,
La réception d'une partie de la récolte m'a permis de constater que les spores sont bien binucléées.

Un autre élément plaide en faveur de Slerotinia slerotiorum : la réaction positive de l'excipulum à l'iode (lugol).

Amitiés à tous



  • message #7437
Hans-Otto Baral, 12-04-2009 22:56
Hans-Otto Baral
Re:Dumontinia ulmariae ?
Thanks, Michel. I wish to add that the idea of Dumontinia ulmariae is not that bad, the diagnosis in the key by Holst-Jensen would fit quite well (except for the spores being "uniguttulate"), but the number of nuclei is not mentioned. Moreover, with the key of Schumacher & Holst-Jensen (http://biologi.uio.no/bot/ascomycetes/Sclero.key.html) the present find keys as a Sclerotinia:

Dumontina: Apothecial outer excipulum composed of brick-shaped cells (textura prismatica) and an inner zone of loose hyphae embedded in a gelatinous matrix.

Sclerotinia: Apothecial outer excipulum of globose to hexagonal cells.

However, I am generally unable to confirm this key because the excipula of my collections of D. tuberosa (spores 4-nucleate) do not at all fit to that key, and I therefore prefer to merge the two genera.

Zotto
Michel Hairaud, 13-04-2009 09:10
Michel Hairaud
Re:Dumontinia ulmariae ?
Merci Zotto pour ces nouvelles précisions et commentaires.

Nothing is easy, then , which I had already guessed! :-P

As for Bernard's find, the ectal excipulum is a quite perfect textura globulosa and I did not notice any gelatinous matrix embedding loose hyphae.

Amitiés
Michel

  • message #7465
Hans-Otto Baral, 13-04-2009 20:54
Hans-Otto Baral
Re:Dumontinia ulmariae ?
I collected today fine D. tuberosa (with Anemone, Ficaria and Aegopodium around) but I have no microscope here in Bavaria.

Will to have drying it and examine when at home.

Zotto
  • message #7468