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Author Topic: Pleione scopulorum buds....  (Read 1292 times)

Alex

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Pleione scopulorum buds....
« on: April 26, 2014, 05:16:18 PM »
....in the attached top two pictures, with white spots on the developing bud. This makes me worry about a virus as described in past discussions here. Any thoughts?

Similarly, the P. X confusa new leaves in the lower two images seem to be unevenly coloured and textured, so what are the thoughts on virus here? Or can this happen with temperature or other stressors at critical developmental periods? The flowers on this one were quite normal btw.

Any thoughts gratefully received.

Alex

Alex

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Re: Pleione scopulorum buds....
« Reply #1 on: April 27, 2014, 10:29:26 PM »
I wonder if Karel or maybe even Paul has a view?

They are in "quarantine" for now, but I've no idea what to do if they grow normally next year...

Paul Cumbleton

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Re: Pleione scopulorum buds....
« Reply #2 on: April 28, 2014, 09:56:44 AM »
Hi Alex,
As you will know from previous discussions in the forum, it is impossible to be sure if a plant is virussed, even if it is tested. So in the end we only have symptoms to judge by. If these were my plants, I would say they had virus and remove them from the collection. But I know how heart-breaking this can be to do sometimes, especially with rarer plants or when they show symptoms in some years but not in others.

An alternative is to decide to "live with" this problem. As long as you are scrupulous about controlling vector pests such as aphids and mites, then it is very unlikely that any infection will spread to your other plants, especially as you have isolated those showing symptoms. I do this with just a very few bulbs such as some P. coronaria that I suspect have virus. Being so rare and having a very small stock of this, I am reluctant to throw them away. But I am trying to raise new stock from seed and if successful I will then throw the suspect bulbs away.

Paul
Paul Cumbleton, Somerton, Somerset, U.K. Zone 8b (U.S. system plant hardiness zone)

I occasionally sell spare plants on ebay -
see http://ebay.eu/1n3uCgm

http://www.pleione.info/

karel_t

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Re: Pleione scopulorum buds....
« Reply #3 on: April 28, 2014, 10:12:51 AM »
Hi Alex,
At this stage it would be really misleading to tell anything about virus. The leaves of P. x confusa are too young and immature and their colour can be changed in a short time. The same is about buds of P. scopulorum. Please show us the photos of developed flowers and mature leaves. You should left them in quarantine all this year. However, the most serious is test them by electron microscope.
K.
Prague, Czech Republic
www.pleione.cz

karel_t

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Re: Pleione scopulorum buds....
« Reply #4 on: April 28, 2014, 10:30:42 AM »
Hi Paul,
It is a good idea to create a new stock by sowing, but you’d always know what kind of virus your plant has, because for example potexvirus may also be transferred by sowing.
K.
Prague, Czech Republic
www.pleione.cz

Paul Cumbleton

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Re: Pleione scopulorum buds....
« Reply #5 on: April 28, 2014, 11:18:25 AM »
Hi Karel,
Of course the problem is that most of us do not have access to virus testing & even if we can find somewhere that offers it, it is far too expensive. It is much cheaper to buy new stock (if available). Also, most labs do not test by electron microscope, only by chemical tests and for these you have to specify to start with what kind of virus you want to test for! Trying seed from virussed plants is worth a go because although some viruses can be transmitted through the seeds, many cannot. Ultimately the health of the resulting seedlings will show if you have been lucky or not.

Paul
Paul Cumbleton, Somerton, Somerset, U.K. Zone 8b (U.S. system plant hardiness zone)

I occasionally sell spare plants on ebay -
see http://ebay.eu/1n3uCgm

http://www.pleione.info/

karel_t

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Re: Pleione scopulorum buds....
« Reply #6 on: April 28, 2014, 02:43:48 PM »
Yes Paul, there is only little possibilities what we can do as an amateurs. As I already wrote, the greatest responsibility for plant health is at nurseries and retailers. Therefore, I am still shocked for their reluctance to test the oddly looking plants.
K.
Prague, Czech Republic
www.pleione.cz

Alex

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Re: Pleione scopulorum buds....
« Reply #7 on: April 28, 2014, 11:25:07 PM »
Dear Karel and Paul,

Thank you very much for this. Your collective advice is very wise, and I have of course isolated the questionable plants. I am not a "hawk" when it comes to virus, and will not be one of those people who throw anything away which has the merest suspicion of an infection, part of the reason being that I strongly suspect for several reasons that plant viruses are *far* more widespread than we imagine. Anyway, as Paul says it is only rarely that we can get plants properly tested, so all will have to be guesswork for now. As an aside my father, a keen grower of Onco Iris, recently did have a chance to get a few plants tested by ELISA, and 2 of 2 (not even chosen because they had obvious symptoms) had Potyvirus  :(. The plants were divisions from various nurseries and, while I'm sure that building your Onco collection from seed might be the best way, who on Earth has access to that??

Alex

 


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