Hi Raul

I only have this photo of Pithya vulgaris (by JP Dechaume). I do not know of VBs in the paraphyses.

Zotto

Thanks Zotto

I was wondering how carotenoids appear inside paraphyses of Pithya vulgaris. In Pithya cupressi I suppose that first the VBs develop and then appear the carotenoids. But I´m not sure if this occurs in this way. It is a type of oxidation? Somebody talks about this processes? Maybe Arpin?

Raúl

Carotenoids

Also seen 4 nuclei inside spores, but if you don´t use software to join photos it is very difficult to show it with only an image. You can see at least three nuclei/nucleoli in some of the spores.
Raúl

Hi Raul.
On a collection made in March 2007, on dead branches of Abies alba, I have written "paraphyses with guttules and yellowish-orange content... ectal excipulum of textura angularis, with cells 15-20 µm, hyaline". No information about nuclei.

Merci beaucoup Nicolas!

I do not think that carotenoids and VBs are correlated. VBs may turn reddish-brownish through oxidation, but the result is never something like carotenoids. Carotenoids are coloured in the living state.

I am surprised that you found VBs in Pithya. It seems I never saw them, but I admit I have little documentation. - Oh, now I see I have the VBs in my drawing of Pithya cupressina, HB 2426.JPG?

Zotto

Yes, I saw your drawing Zotto.
Then, the colours of Pithya are because the presence of carotenoids or not?
Another question: carotenoids are evident from the first stages of development of apothecia (in any genera that have them)?
I´m used to see nearly white Pithya cupressi in the first stages of development and when they are covered by the Cupressus/Juniperus leaves. I attach the macro of the apothecia to which the microphotos belong.
Raúl

Yes, surely the colour is only because of the carotenoids. As you can see from externally, the colour is present already when very young. Yes, I also know this pale form. Development of carotenoids is probably supported by light, but I am unaware of pale apos getting bright-coloured with age, if the light conditions are not changed.

The new forum looks very nice, but when typing the answer, I can only see Raul's first mail, not his last to which I wish to answer....



Zotto

Well, then I have problems to find the carotenoids in these pale forms. I don´t know where to look for them. 
In the previous photo, where I asked for carotenoids in paraphyses, I signaled pigments that in my opinion are the responsables of the apothecia colour. Because I saw them in paraphyses where the VBs where scanty or starting to dissolve, then I thought they were related to the VBs. Do you think they are not carotenoids? Maybe just an oxidation of the VBs? 

Me too, I would prefer to see the hole evolution of the dicussion. By now I just open a new window. 

Raúl

My impression is that the pigment on your photos is outside the vacuoles which would point to carotenoids. Usually you can stain carotinoids with IKI (in greenish), but mainly when they are strongly coloured.

Zotto

Also carotenoids should resist KOH?

Hi Raúl,
 indeed it is strange i cant see the whole discussion while reponding, yesterday i thougt there was work on the site because i could not repond. Today  i found out Internet explorer did not sign me in automatically.
The carotene in paraphyses are not in all species evident when young, in Neodasyscypha and Proliferodiscus the guttules appear more greenish when young so the Hymenium looks more black
for the Pithia vulgaris i found in januari but did not make any notes about the excipulum or paraphyses but i made a IKI test for the spores to see if there were any glycogenes. The sporewall turned blue on the outside and red on the inside so there seems to be some glycogene accumilation on the inside of the sporewall. For nuclei I did not look but judging my photo i see only two
cheers,
Stip 

Thanks Stip
Did you take data about living spores measured in water? I´m also interested in that info. I see that Nicolas talks about (13) 14-16.

I noticed glycogen in Pithya cupressi, see pics. Also seen this kind of blue aureole. But, at least in my case, I think it is because chromatic aberrationsof the ocular/objective. Maybe it is enhanced due to the characteristics of the outer wall in this genus. I add also a picture in IKI + KOH with different focus and you can see with one focus the aureole but not if you change the focus. In those spores where the outer wall is more separated, the blue aureole is enhanced, maybe the bigger space and the light passing through IKI gives this blue appearance (aberration)... I don´t know.

Raúl

I also need to log in every day....

Carotenoids do not disappear in KOH, yes, but when VBs get oxidated, the colour may be also quite resistent to KOH.

The bluish and reddish colour around the spore wall I also think is an optical effect, like in the rainbow. Not due to microscope optics, only because of differences in the density of spore wall and water arond.

Zotto

Hi Raúl & Zotto,
This color reaction is too obvious i think for a optical effect. In fact it remembers me of the basidiospores of Leucocoprinus capillipes (the outer wall, inside they have one large Glycogene body) i tested with IKI and they are said to be achromatic, next time i will test Cressyl bleu on the spores. I am sorry but i did not make any measurements of anything.
Cheers,
Stip

Thanks Zotto & Stip

Here I attach a photo Plicaria leiocarpa spores. All in water except those of the right hand at the bottom. Because I see the blue aureole also in those in water, I think It has to be an optical efect, at least in my microscope.

Raúl

Hi Raúl & Zotto,
it seems you both are right, it is an alternation of the light spectrum. And i get curiuos now what causes that, most likely it is not the optics when it is seen in 3 different microscopes. Next time i will do some more extensive tests, or it could be the sporeshape perhaps
cheers
Stip