Fungus on Sonchus.asper - help to ID needed please

[JohnWB]

Hi, I'm a new member and this is my first post. I live in Cumbria, UK.

URK.... just realised I labelled this topic with Sonchus.asper - my-stupidity! This post actually deals with Sonchus.arvensis! Sorry folks.
All images are from Sonchus.arvensis NOT S.asper.....

I study British wildflowers as my hobby and make permanent slides of them - these I then look at with my microscope - the other part of my hobby.
I've come across an interesting fungal-invasion of the leaves of a Sonchus.asper that I've been working with. Having virtually no knowledge of fungi I thought this forum looked like a great place to visit and join as the more I see of this fungus the more interesting I find it.

Having had a good look around the web I suspect it may be Miyagia pseudosphaeria but this really is little more than a guess really as to actual species, although I think it may well be something of the sort?

[Chris Yeates]

Hello and welcome to the forum.

Hardly a guess - you are quite correct, this is stage II of Miyagia pseudosphaeria. The key feature is the ring of dark brown paraphyses, with practice and with a x10 lens this feature can be recognised in the field.

The only other rust on Sonchus spp. is the plurivorous Coleosporium tussilaginis which looks very different.

If you know your plants then the study of plant parasites like this can be an excellent way to begin mycology as most are narrowly host-specific. Their identification is often much more straightforward than the macrofungi. Have a look at the http://fungi.org.uk/viewforum.php?f=9 sub-forum . . .

Excellent images - how did you do the section?

Best wishes
Chris

[Lancashire Lad]

Hi, and welcome to UK Fungi.

I think you are correct with your suggestion of Miyagia pseudosphaeria.

That species is one of two "rust" fungi that attack Sonchus species. - The other being Coleosporium tussilaginis. - But of the two, only M.pseudosphaeria has the dark paraphyses which surround the sori.

See this thread: - viewtopic.php?f=9&t=428 (But note that it refers to S.arvensis and not S.asper).

Your micro-photographs are excellent, (I wish mine were as good!), but a couple of images at lower magnification, showing the "macro" characteristics of the rust attack would also have been useful.

Also, I'd look for some spores. - Photos and measurements of those are generally needed with rust fungi - (but I think you are safe with M.pseudosphaeria in this instance.

See the extract below, from "British Rust Fungi - A guide to their identification by Host Plant", published in 2004, by D.M. Henderson: -

1.JPG (22.83 KiB) Viewed 2100 times

Regards,
Mike.

EDIT - Chris got there first! - My post was delayed by my fighting with Windows snipping tool to get the text extract!!!!!

[JohnWB]

Thanks chaps, I tried to include more images but every time I added an attachment (image), inline or not, it's addition seemed to cause an earlier image to be 'no longer available' when I checked the preview prior to posting.
Perhaps as this is my first-ever post to this nice forum?

I'll try to post a few more images below,

Seems to be OK now, I'll try to add some more images later.

[JohnWB]

Hi again, I ordered this book earlier today, I'm hoping it'll be a good resource for my future encounters with plant-fungi.
They (fungal-infected plant tissues) make excellent slides and I'm certainly going to look for more on British wildflowers that I collect.

This is the book - does anyone know if this book has a key, such as that in Stace's fabulous Flora?

book cover.jpg (14.95 KiB) Viewed 2044 times

[JohnWB]

Hi, my original post with the images of the fungus on Sonchus has vanished! Can anyone help - I'm new to this forum and think I'm doing something wrong...

Thanks, John B. (JohnWB)

[Lancashire Lad]

Hi, my original post with the images of the fungus on Sonchus has vanished! Can anyone help - I'm new to this forum and think I'm doing something wrong...

Thanks, John B. (JohnWB)

Hi,

I've managed to reinstate your original post, so the thread makes sense once again.
I'm not sure exactly why it would have disappeared like that. - It may have been because it was your first post as a new member, and you had subsequently edited it (to add the Sonchus arvensis note), after response posts had been made, which might have resulted in your original post requiring admin approval once again.

Anyhow, good to know that we are all on the same page about the species involved!

With regards to your problems with image attachments behaving oddly and disappearing, I would ask that you "bear with us" and persevere with the current situation as best you can.
There was an "upgrade" a couple of months back, to the underlying phpBB software on which the UK Fungi website runs, which Adam ("adampembs" - the site owner/administrator) implemented at that time.
Unfortunately that "upgrade" has had a couple of unwelcome effects to how the site is behaving, and Adam is working on trying to discover exactly what elements are causing the unwanted behaviour to get it sorted out.
Everyone who tries to upload multiple images is in the same boat, all presently trying to work around the problem.
If you have a look at this post: -
viewtopic.php?f=10&t=1968#p9593 (You may need to be logged in to see that post)
you will see how I'm currently managing to get around the problem. - Hope that is of some small help.

Regards,
Mike.

[Lancashire Lad]

Hi again, I ordered this book earlier today, I'm hoping it'll be a good resource for my future encounters with plant-fungi.
They (fungal-infected plant tissues) make excellent slides and I'm certainly going to look for more on British wildflowers that I collect.

This is the book - does anyone know if this book has a key, such as that in Stace's fabulous Flora?

book cover.jpg

Hi again,

That book, although now 20+ years old, is extremely useful - although, as you will probably appreciate, and as comprehensive as it is, there are still innumerable fungi species that aren't included. (I don't think that a fully comprehensive single volume could exist - or if it did you'd probably need a JCB to pick it up! ).

It does contain typical keys, (fairly similar to Stace), and it has very comprehensive "host" and "fungus" indices.

You will inevitably encounter many of the rust species when looking at plants & flowers (indeed any flora - trees, grasses, ferns, whatever).
If you want to get a handle on the types of rust involved, I would particularlyy recommend the following books: -

British Rust Fungi - Malcolm Wilson and DM Henderson (ISBN-13: 9780521279260)

Checklist of British Rust Fungi -D.M.Henderson-A checklist of the Rust Fungi of the British Isles. British Mycological Society, RBG Kew (ISBN 0-9527704-4-X)

Henderson, D.M. (2004). The Rust Fungi of the British Isles: A guide to identification by their host plants. British Mycological Society, RBG Kew (ISBN 0-9527704-9-0)

In the site's Rusts/Smuts/Mildews forum; - viewforum.php?f=9
There is a comprehensive listing of recommended rust & smut fungi literature, here: -
viewtopic.php?f=9&t=23

Regards,
Mike.

[JohnWB]

Many thanks Mike, I'll try the workaround. Thanks also for the book-list - I'm as you say certain to see fungi in and on plants, and now I see how interesting they are and what good slides they make I'll certainly be including infected-tissue in my slides! A very interesting area indeed - great to find this great forum.

Here's an attempt to post a few more labelled images to give some sort of context to the images.
You'll see mostly microscopic images from me as microscopy of British Wildflower structure and taxonomy is my great passion. The fungal content is proving to be a really interesting 'off-shoot' to this also!

[adampembs]

The hosting company had issues with the database server that they tell me are resolved. Sorry for the inconvenience.

[JohnWB]

Hi all, I've cut and mounted some thinner sections of 5µ (the earlier images are of 8µ sections) and changed the staining to try to make finer details more visible.

Here are a few views of what I think are hyphae having entered the unfortunate Sonchus.arvensis via stomata.
The hypha internal image seems to show the hypha making it's way through the cortex of the stem using the intercellular spaces rather than penetrating cell-walls to move directly through cells. In the image it has arrived at the vascular-bundle fiber-cap - beyond which in the direction travelled, lie the phloem sugar-conducting vessels - could this be the target for the hypha to take nutrient from the Sonchus food-transport directly?

The more I see of these 'micro-fungi' on plants the more interesting they become - including the different stages - up to 5 in Miyagia.pseudosphaeria (the probable identity if this 'Sonchus fungus' it seems.

[Lancashire Lad]

Hi John,

Thanks for bearing with us re the current "multi image" upload problem. - I'm pleased that you are managing the workaround effectively!

And thanks again for your updates on this topic, and your truly excellent photos.

Your microscopy techniques of sectioning/staining/photography are as good as I've ever seen.
If you would be willing to give a description of the techniques you are using, (perhaps as a new topic in our "Microscopes, Cameras, Equipment, & Technology" forum, I'm absolutely certain that many of UK Fungi's members would find such an insight very interesting indeed!

I can't claim to be much more than a beginner with rust fungi (and with any other fungi come to that. ).
Chris Yeates is THE expert in that field, and I'm sure he will comment on your images when he sees them.

I think I'm correct in saying that all rust fungi obtain their nutrients from the host plant by way of specialised cells named "haustoria" which they produce once they've penetrated into the host's leaf or stem.

Perhaps worth looking for, as with your microscopy skills and sectioning technique, I'm sure that you would be able to get some outstanding images!

In case it's of interest to you, here are a couple of links to articles that give an overview of what goes on when a rust fungus attacks a plant: -

http://journals.plos.org/plospathogens/ ... at.1004329

http://www.pnas.org/content/98/14/7654

Regards,
Mike.