I wonder if growing them here where it gets HOT for long periods of time has potentially done something similar? Perhaps, the weaker symptoms have inoculated many of them with weaker strains, possibly preventing greater infections? If you can’t have them without virus, maybe weaker versions to immunize them against worse ones wouldn’t be all that bad, would it? Kim
See link below for a Google Scholar search of “cross protect” and virus and plant.
Link: scholar.google.com/scholar?q=%22cross+protect%22+virus&hl=en&btnG=Search&as_sdt=1%2C36&as_sdtp=on
Don, where are you going to get VI specimen of the species you want to use? Kim
Kim,
Indexed species roses don’t exist afaik but there are collectors of wild species seed from which to build breeding populations. There’s no way to know whether plants from these seeds are virus free until a screening method becomes affordable but they do offer the best prospects. Keeping them virus free is the challenge, probably an impossible one.
My roxburghii, chinensis, wichuraiana and omeiensis were grown from seed collected in China, for instance. A couple of my omeiensis are from seed provided by the USDA, in fact, frozen for 25 years or so. They have quite a few species in the fridge. Others came from QH and from private individuals.
I have other species roses that appear to be virus free but can’t know for sure. Do you think your fedtschenkoana are virus free?
Hi Don, Fedtschenkoana virus free? Lord only knows! I haven’t witnessed any symptoms, but who knows if it WOULD show them? I obtained mine many years ago from a fellow Huntington volunteer who bought it from Pickering in Canada as it wasn’t available anywhere else on this continent at the time. Coming from Canada, it should have been budded on multiflora seedling, FWIW. She had a large rose collection and grew this at the bottom of her slope, along the fence, bounded by a huge stand of oaks outside the fence. The deer noshed the tops over the fence; the rabbits and gophers munched it where they could reach.
I then grew it in my HOT Newhall garden, where it was pretty much left alone because the vermin loved the other modern roses better. The only munching on it there was from the enormous rat which ate out the center of the stand to build her nest. The plant should be free from everything due to all the toxins and other substances I dumped in that blamed nest to finally send her to her reward. Have there been any studies to determine if transmission can be accomplished via deer, gopher, rabbit or rat? hehehe
I hit it with just about any pollen I could collect and very little took. I’ve only grown it from suckers. Hers was planted deeply so it would sucker and mine in the old garden, was planted in heavier soil at the one end of the slope to prevent it from eating the entire hill. What it did take with was, of course, Orangeade, which would be a good candidate for being infected. My Orangeades have always come from Sequoia where propagation was done in very high heat from very soft cuttings. I wondered then, and thought of it again after some of Henry’s recent posts, that perhaps it may not be infected, or at least have a lower viral load due to the conditions under which it was produced. Ralph always said he was never able to deliberately spread infection in his green houses, but they were HOT from early spring through late fall, and he based that upon performance and observation of symptoms. Though not a “cure”, perhaps a potential reduction of infection? They processed a ton of known infected varieties and we frequently noticed and commented on how much more vigorous the newly propagated plants were compared to their source plants. I chalked it up to Clair Martin’s statement that “sometimes you have to reintroduce juvenility into the plant”. Seems “juvenility” might equal lower viral load?
Do I think the Fedtschenkoanas are uninfected? Absolutely not! I don’t think most roses are uninfected. I have long felt, as has been stated in some of the research Henry has cited, just because our tests can’t detect infection, doesn’t mean it doesn’t exist. I treat them all as if they are infected. Have for many years. When I’ve shared material, I’ve always stated if I knew the variety was infected (demonstrated symptoms) as well as if it was from the original seedling. Kim
If you are interested in reading about the latest that is being done with another plant virus, the following link wil take you to a just released “International Symposium on Plum Pox Virus”
Thanks, Kim.
The HMF listing for OADEFED mentions your having two seedlings from the cross of Orangade with Rfed. Were those the only seedlings from the cross?
Hi Don, yes, those were the only two to germinate and survive. I have the original seedling of the once flowering one still in the fifteen gallon can. I have a five gallon sucker of the repeat flowering one. The five gallon plant will make it into the ground this summer, if this heat doesn’t do me in first. The once flowering one is destined for the trash can. I just don’t have any level space left and I know I’m not going to do anything else with it. It’s a lovely plant and quite interesting, but I prefer playing with the DLFEDs instead due to their inclusion of Legacy genes. Of those, only DLFED 3 and DLFED 4 will be retained. All of the others will be going away for the same reason. This hill is too steep and slippery and water is too great an issue to mess with putting anything else down hill.
So, should anyone be interested in suckers, cuttings, etc., please speak now. I need the path space and keeping them watered is an increasingly greater issue as time goes on. Kim