Tobacco Rattle Virus

[boomkweker]

TRV is definitely able to infect Epimedium: http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS.2000.84.12.1344A. I don't know exactly how prevalent it is, but those claims from http://www.perennialnursery.com/forums/viewtopic.php?f=1&t=54531#p473122 are worrying and appear trustworthy, albeit understandably unpleasant. At least that guy reveals where he got his information, which cannot be said of many other sources.

The incidence of TRV in various European nurseries is alarming. Jānis Rukšāns often complains about infected commercial stocks of Crocus right here on this forum. All this leaves little chance for Epimedium to be spared, particularly as it is mostly propagated vegetatively.

I wonder about Epimedium and not, say, Heuchera because I am very interested in the former and not at all in the latter. I would be happier if they weren't susceptible to any virus, but such is life, and I prefer to know more about what may be going on in my garden. If anybody is willing to discuss TRV in other plants, e.g. in Crocus, they are most welcome, of course.

And TRV-infected plants don't always deteriorate: In TRV-infected plants, the virus RNA levels are initially high. However, these levels decline and the diseased plant enters a phase, referred to as recovery, in which symptoms are mild, the plant is immune against secondary infection with similar viruses, and virus replication persists at a low level. (http://onlinelibrary.wiley.com/doi/10.1046/j.0960-7412.2000.00942.x/full). But unfortunately they remain a source of infection for other plants.

[James Cheshire]

I have four Epimedium that are infected with TRV, though they don't always show the symptoms. My heavy soil doesn't support the nematode vectors, and I haven't seen any evidence of it spreading to other plants (even Solanaceae, which are highly susceptible). I've seen TRV-infected Epimedium, Hosta, Anemone and Dicentra in other gardens, too.

If you can get a hold of it, the following paper might be helpful:

Schmelzer, K. 1957. Untersuchungen über den Wirtspflanzenkreis des Tabakmauche-Virus. Phytopathologische Zeitschrift 30: 281-314.

It provides a large list of plants, and whether they suffer from systemic, local or no infection from TRV.

James

[Lesley Cox]

Whatever has been wrong with my Mertensia, I think it can't be TRV. After I cut off all the foliage and gave it a good water, it is now sprouting away again, which it shouldn't be doing at this time of year (mid autumn). So far the foliage is perfectly clean.

[boomkweker]

Just a couple of pictures of virused Epimediums I took in a botanical garden back in May, to give people a better sense of what to watch for:





It was mostly E. x rubrum. Most of the symptoms were hidden beneath healthy leaves, so it was not immediately obvious that the plants were diseased, but upon a closer inspection the infection seemed rampant there. Unfortunately I didn't have a chance to check it later.