Hi,

Yes that's good : probably Apiognomonia errabunda, please compare.

Alain

Thanks Alain, for the paper also

Hi, Dragisa,

If possible, check Apiognomonia petiolicola. It has biguttulate spores,
smaller cell of the spores is orientented towards the apical annulus, septum is situated nearly at 1/3 of the spore length. Apical ring of the asci is ca. 2-2.5 micrometers long. Exclusively grown on dead petioles of Tilia.

While in A. errabunda the apical ring is somehat bigger - about 3-3.5(-4) micrones; the septum is between 1/4 to 1/6 of the spore lenght.

Here is the apical ring

Hi Dimitar,

It's a good suggestion (we don't observe it in France, so I forgot it !), but ascospores size doesn't fit. I agree with the 2 features you mentioned.

Best wishes,

Alain

I read Sogonov & al (2007). They don't talk about arrangement of ascospores in ascus, but in the plate concerning A. errabunda (Fig. 2), one can see in photo H the smaller cell oriented towards the top of ascus (unlike in photo G). Molecular sequences have been obtained, and inp.  G & H, it is A. errabunda. Could we think that orientation of ascospores is not a constant feature ?

On the other hand, they give apical ring size : 2,5-4,5 µm.

Please Savic, check all these features with several ascomata and tell us your conclusion. Interesting.

Alain

 

Not a problem, but next week I'm on vacation. If you're interested I can send you a sample.

Oh yes, with pleasure.

Alain Gardiennet

14 rue roulette

21260 VERONNES (France)

Hallo Dragisa and Alain,

According to the species's descriptions the apical ring of A. petiolicola is 2.5 micrones in length (Monod 1983 ), while in A. errabunda is above (2.5-4.5 in diam.).
I agree that the fungus  fits more towards  A. errabunda sensu Sogonov et al. (2007), however the guttules in the spore cells are qiute big - in the sence of A. petiolicola (see Monod 1983), and those on every photo taken by Dragisa here in are qiute big too!

A. errabunda is similar, according to Monod (1983) & Sogonov et al. (2007) in morphological features, to A. veneta, and both species posess qiute small (petite) guttules.


Best wishes,

Dimitar

Thanks Dimitar,
I send sample to Alain, we will see his analysis.

Hi,

The letter is at last arrived the 22 july !  4 months to come, the postmen are not ready for olympic games...

I studied it and confirm Dimitar's proposal.

Probably there is a mistake in the plate of Monod, as I mentionned. The orientation of ascospores in asci is a important feauture and here I verifie that ascospores are always oriented towards apical ring, in evry asci.

I measured free ascospores : 13-13,5 - 3,3-3,6 µm, with a septum located at 1/3 to 1/4 spore length, so closer to petiolicola than errabunda.

Other features, already mentioned,  fit well with A. petiolicola.

Next spring, it woul be a good idea to get molecular data for this fungus.

Best wishes,

Alain

Merci Alain,
I'll try to find more samples next spring.