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02-07-2025 18:45

Elisabeth Stöckli

Bonsoir,Sur feuilles d'Osmunda regalis (Saulaie),

02-07-2025 17:26

Yanick BOULANGER

BonjourRécolté sur une brindille au fond d'un fo

02-07-2025 09:32

Nicolas VAN VOOREN Nicolas VAN VOOREN

Hello, bonjour.Here is the paper I'm searching for

30-06-2025 16:56

Lydia Koelmans

Please can anyone tell me the species name of the

01-07-2025 23:37

Josep Torres Josep Torres

Hello.A Pleosporal symbiotic organism located and

30-06-2025 12:09

Edvin Johannesen Edvin Johannesen

This tiny, rather "rough" erumpent asco was found

30-06-2025 06:57

Ethan Crenson

Hi all, Another find by a friend yesterday in Bro

30-06-2025 19:05

ALAIN BOUVIER

Bonjour à toutes et à tousJe cherche à lire l'a

30-06-2025 14:45

Götz Palfner Götz Palfner

This is a quite common species on Nothofagus wood

25-06-2025 16:56

Philippe PELLICIER

Bonjour, pensez-vous que S. ceijpii soit le nom co

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Updated* Gazania LEAF BLIGHT
Ciara Luna Gomez Escoin, 05-07-2023 10:26
Ciara Luna Gomez EscoinHello again,
I deleted the topic because the gazania problem was not caused by any fungus, however, just in case someone had the same problem, I leave it with the updated info.
We noticed we had the same stains on Zinnia and Aster, and the leaves also got "splitted" in a transverse plane, but in these cases I saw no hyphae with the microscope. We realized that this is caused by some kind of minator insect (or arachnid).
I'm doubtful about the fungal nature of the filaments I saw in Gazania. Also, the supposed sporangia may not be fungal structures. I'll keep watching.



Hello everyone,
Two weeks ago we detected some Gazania plants (at stage III after germination) which had some kind of blight as you can see in the pictures: the colour is dark grey, at first it involves the tip of the leaf, and then the stain gets bigger and bigger, but there is a clear and straight boundary between healthy and ill tissue. The upper and back sides of the ill parts of the leaves splitted easily. Also, I could see a mycelium over the upper side of the leaf using a manifier.
I took some samples and I watched them at the microscope. I saw what I think they are hyphae, but I couldn't see any reproductive structure. I put some damaged leaves in a Petri dish with water and I waited some days (I have a quite rudimentary lab to do these kind of analysis...). Then I prepared new samples to see at the miscroscope and I could see also the same hyphae and what it might be round 16 ?m diameter sporangia, but I'm not able to identify these structures. Could you please help me?

THANK YOU VERY MUCH!!!

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Angel Pintos, 05-07-2023 19:26
Angel Pintos
Re : Updated* Gazania LEAF BLIGHT
Hola Clara,

te has fijado si el micelio tiene septos o no?, los micelios de los Oomycetes no son septados excepto cuando son muy maduros.

Las estructuras de tu imagen parecen esporangios inmaduros, parecen de Pythium.

Un saludo

Angel
Ciara Luna Gomez Escoin, 06-07-2023 14:55
Ciara Luna Gomez Escoin
Re : Updated* Gazania LEAF BLIGHT
Hola Ángel!!

En primer lugar gracias por tu ayuda. Los filamentos no son septados. Aquí en el invernadero he visto casos de Pythium, pero sólo en raíz. Me parece extraño que no haya más estructuras reproductivas. He llegado a pensar que no se trate de un micelio, sino de la telaraña de un ácaro tetraníquido, incluso, pero no he podido ver ninguna otra señal de su presencia.

Muchas gracias!!!

Ciara