One stem of a potted Yellow Brick Road in greenhouse showed this funky thorniness. I’ve since tossed it out.
We don’t have any native R. multiflora around here, and I’ve never seen anything resembling RRD before. (although I’ve since seen one stem of L83 out in the field that looks a little funky)
Anyone want to register an opinion based on the photograph below?
Joe, I’m no expert but any time I’ve seen RRD there has been a lot of red coloring involved with both leaves and stems.
Could be. The morphology is right although I might expect greater narrowing of the leaves and more than a single affected shoot.
The lack of red coloration could easily be due to the absence or near absence of anthocyanin genes. It seems to me that a principle symptom of RRD is a hyperactive meristem with overproduction of secondary plant products. If the plant lacks the machinery for producing anthocyanins (or it is hobbled) then there is nothing for the virus to overstimulate.
Still, it is not unusual for a such a shoot to appear on a plant that is otherwise quite healthy. Other things than viruses can overstimulate growth. I would have kept the plant and watched for other symptoms while applying liberal doses of miticide all around.
I have had but one case of RRD so I am also no expert. It is not unusual for a low thorned plant to shoot up an occasional or even a single heavily thorned stem. That individual plant appeared to have enough pigment in it to express the hyper pigmentation that RRD exhibits. I think I would have quarantined it and waited for the bud to bloom, which would have showed the distortion that RRD causes. However, it it was nothing special or a duplicate cross would be made again, I think it is best to be safe than sorry. I don’t think that the RRD is quite so contagious that it could not be easily quarantined. The RRD produces shoots that scream “I have a problem”, and even though you might not recognize it, you will know that it is a problem.
I am dealing with RRD in my NJ garden this summer. I have a question for the experts. Is red foliage now in August indicative of RRD? The new foliage does not have lots of thorns on it.
Mostly, I am using the high thorniness to diagnose infected plants.
Cathy
Central NJ,zone 7a
Red foliage is relative. For the red/pink K.O. roses, their foliage is already intensely red, so it’s hard to make it appear redder. But with wild R. multiflora, the shoot tips are normally only slightly, if at all, reddish. So when you see red it means something’s going on. I just returned from western PA where there’s massive infestation with RRD. Lots of red shoot tips. But actually the virus is not particularly virulent there. Bushes go on for years with the disease. It doesn’t jump from one clump to the next in any discernible pattern. Deer love to harvest the young shoots, pruning them back to repeatedly regrow.
Some roses lack the ability to produce red in their foliage at all, for instance some yellows and whites. So if those were infected, I doubt you’d seed reddening of the foliage. One thing I look for is fatter than normal shoots. You see tip shoots that look like basal breaks on top of spindly stalks. Of course the spininess is often notable. Overactive hormones.
Overactive hormones.
Not direct up-regulation?
I don’t know enough about the virus to say what’s direct and indirect. I think of crown gall, which is from a bacterial infection, but with transmission of a plasmid that is basically a naked virus which gets incorporated into the plant genome and then makes the gall grow.Hairy root is about the same but does its thing on roots instead of shoots. I don’t think a virus carries many genes for hormone production per se. More likely to affect the regulation of pathways already there. If there is a complete sequence of the virus out there we could make some guesses. For all I know, it makes an RNA that interferes with the normal down-regulation of some hormone pathway. I haven’t looked yet to see if the whole sequence is out there yet.
I have been out of town for a week and checked to see what needs ferts, etc., and at first I thought this is what is the problem with this one. This is a huge yearling seedling, a R.foliolosa
X Henry Hudson cross, which has very light stems and foliage-no trace of red in the plant thus far. However, this is the normal foliage, middle pict., and this is the new growth. It is thorny to start with and I really do not see a whole lot of difference from the new to the old growth with regards to thorns, but these elongated narrow skinny leaves are screaming “problem” and this is starting to look a bit like RRD. What do you think? I may have 4 of these that are doing this, just not so advanced. Have already pulled them out, will bag them up tomorrow I believe. The pictures show about 1/3 of the plant, half of which is normal and half is elongated and yellowed. Is there another problem disease that causes this, or could this be RRD?
Not what I think of with RRD but clearly abnormal. Maybe David Z. can weigh in here with an opinion, he’s made a hobby of collecting virused roses.
What we need as rose breeders is a quick, cheap and reliable assay for viruses.
But, why should we have RRD here in the arid, hot Southern California area, Jackie? I had a branch of Careless Love which threw foliage like the bottom photo many years ago. The flowers were quite “twisted”, too, but had all the expected parts. It was weak and didn’t live very long, but the rest of the plant was fine. It impressed me as being something similar to what created Watsoniana.
I think the new foliage on most of the plant most resembles what is in the top photo. I tried to get a very representative photo of each side. I have no idea what this is, but the normal foliage is nothing like what is now growing. If I ever recover the photos on my old motherboard (it is in Maryland right now) I may be able to post a picture of the plant that I am quite sure was infected. It happened in a wet yr., in the late spring when new flowers should have been abundant, but all I got was witches brooms, twisted and thorny stems that shot straight up, and it was all a burgundy wine color. I have no doubt that was RRD, even though I did not figure out what the name of it was back then for about a yr. The rose was Daydream. I have no idea why we should have RRD in California, but I do not believe it is unheard of here. And it does get humid and rainy here, just not now or in the recent past. I do not believe this is normal growth and maybe I should not have posted it here but I do think there is a possibility it is RRD.
Sure, anything is possible and there is no reason for you not to post the question and photos here, Jackie. Was this a new plant you recently obtained, or had it been in your garden some time? I’m wondering HOW the disease and the mites which carry it arrived in your garden to infect a plant. The whole idea of course, scares the mess out of me. If they can find YOU out of the blue, they sure as heck can find ME.
It looks like classic herbicide damage. Any chance of some overzealous Roundup usage in the area or other herbicide that drifted?
One small update to my post: the stem of L83 that I thought looked infected is putting out branches and appearing more normal.
It looks a lot like herbicide damage, Jackie.
Peter
This is not within 300-400’, probably more of another garden. It is quite isolated with only other roses (mine) around and an organic orchard about 3 to 4 hundred ft below but up canyon. This rose is also in the center of about 60 roses which should also have been affected by something like herbicide. I am on 3/4 acres, the next property is 5 acres and the next is 1 acre. None of them have lawns on the sides of their houses that face mine or on the windy side of the canyon. Lots of native stuff because we all face the canyon. When I found the DayDream infected yrs. ago, I also came to the conclusion (initially) that it was herbicide induced, because it was on the portion of property above the orchard. But the lady who takes care of the orchard said she has been all organic for years. I am going to go down and check out all the roses in that area along with the other couple that look like they might also be suffering from whatever this one is suffering from. BUT, when Daydream became infected, I pruned off the infected parts deeply and it continued to grow (feebly) and bloom (not much) for another 5-6 yrs until I pulled it. The new growth never showed signs of RRD but it definitely was not the same plant it had been before. And I agree it looks a lot like herbicide damage, but I am almost positive that it could not be under the very isolated circumstances that these are grown in.
I know this “foliolosa seedlings syndrom”.
I have it yearly on some seedlings with foliolosa ascendent. There is no remission. Quite obvious at young seedling stage or later. Transmissible to other roses.
I guess it is a seed borne virus.
Pierre, “foliolosa seedling syndrome” sounds interesting, because I did check the other seedlings on that table and maybe two others look similar but not so 'advanced. They are both foliolosa seedlings. One other is showing similar tips in a different area. Also foliolosa. Any other information available? My foliolosa x hybrid acicularis and my foliolosa x Cafe Legacy do not show any symptoms. All of the problematic ones are foliolosa x Henry Hudson, not necessarily from the hip but from the same yr.
R. foliolosa itself has long thin leaves
See: