a virused 'Katharine Hodgkin' ?

[biodiversite]

comparing our photos of 'Katharine Hodgkin' on my french forum, we saw different variations of colors, i. e. it seems that in acid soil colors are stronger : do you make the same conclusion ? Moreover, one of our membre has a form with some broken colors (at the bottom of this page : http://plantes-passion.forumactif.fr/les-bulbes-f7/iris-reticules-2008-t1386-15.htm sorry the photo is too big for this forum !) : do you think this plant could be virosed ?

[David Shaw]

It is certainly an unusual form, Biodiversite. I usualy associate virus with streaks on the petals, in this case the streaks are missing! I think your forumist should isolate the pot for the time being until you get an answere.
 See Dominique's 'Sheila Anne Germany' in the Reticulata thread.

[mark smyth]

here's the photo

[biodiversite]

thanks for the redimensionned photo and the answer : then, if not a virus, what could be responsible of such aspect ?

[biodiversite]

then, the answer is perhaps there : http://www.srgc.org.uk/smf/index.php?topic=1194.225
it could be 'Sheila Ann Germaney' virosed...

[Ezeiza]

Hi:
    That 'Katherine Hopkin' material was virused has been known for years but this is true of several Reticulatas. Virus in the foliage is highly evident.

    The images show unusual stripes but the emerging foliage will show unmistakingly if the plant has mosaic or not.

Regards

[ashley]

Alberto,

So do you think that the converse is also true, i.e. that plants with apparently healthy foliage are probably not virussed (even if the flowers show some coloured streaks, as here for example)?

[biodiversite]

moreover, iris viruses are specific or not ? I think for example to Tulipa platystigma witch is always infected when coming from Holland...

[Ezeiza]

Hi Ashley:
             
               I wish things were different but in Iridaceae viruses show in the flowers and not in the folaige at times. There is a virus that affects Babiana, Sparaxis, Tritonia, Dierama, Watsonia, Freesia, etc. that shows as darker stripes in the flowers but no signs are seen in the leaves. It is highly infectious and would wipe the plants. There is at least one strain that passes through the seeds to new plants.

               Using high nitrogen, the leaves of many bulbs develop a dark green colour that masks the virus symptoms in the leaves.

Regards

[Maggi Young]

There is at least one strain that passes through the seeds to new plants

AARRGH! Frightening prospect.
 Would you agree, though, that is is worth trying to take seed from most plants that one suspects with a virus, in order to get clean new stock?
How would the amateur grower recognise the particular virus which can be passed even through seed?

[Ezeiza]

Hi Maggi:

              This particular strain was propagated in Southern England and the seeds were sown as "capable of reproducing the pretty markings in the flowers". The symptoms were darker color stripes at random along the veins.


              Of course, one can clean a particular species from "normal" viruses from seed. The problem is that when a plant shows visible symptoms it is already too weak to produce any seed.


Regards

[Maggi Young]

  The problem is that when a plant shows visible symptoms it is already too weak to produce any seed.

Well, that's not always the case: we have quarantined plants of other genera and got good seed from them before destroying the affected plants and in the context of this thread, we have specifically done this with Iris winogradowii.

[biodiversite]

Maggi, do you have photos of this infected Iris winogradowii ?

[Maggi Young]

No, Bio, I regret I do not have such photos.