In any rose breeding program, disease resistance must be a priority. It is no longer acceptable to put on the market new roses that are not disease resistant, although you wouldn’t know it because professional rose breeders are still introducing new cultivars that lack disease resistance.
One of the most valuable rose species to use in a breeding program to develop disease resistance is Rosa wichuriana. If we compare, for example, the Canadian Explorer Rosa kordesii and Parkland series it is no accident that the former is generally much more disease resistant than the latter. The reason is that the Explorer Rosa kordesii cultivars have a relatively heavy dose of Rosa wichuriana in the pedigree. Conversely, the Parkland cultivars do not have a species in their pedigree that is disease resistant.
It’s interesting that although Rosa rugosa is generally quite disease resistant, it is notorious for losing it when hybridized with other species or cultivars. But combined with Rosa wichuriana, the hybrid ‘Max Graf’ is very disease resistant, as is the amphidiploid Rosa kordesii developed from it. Why then has Rosa wichuriana not been used more in hybridizing with other diploid species or diploid species hybrids to develop disease resistant amphidiploids? Two hardy diploid species hybrids that have already been developed are Rosa rugosa x R. nitida (‘Aylsham’) and Rosa blanda x R. multiflora (‘Ames Climber’). ‘Therese Bugnet’, while a complex species hybrid is a diploid and should also be promising. Rosa rugosa has also been successfully hybridized with the diploid Rosa hugonis, and this cross should be repeated again to develop a hardy hybrid with yellow colour. Keep in mind that the wider cross between two diploid species is better to have decreased fertility in the hybrid, because then the more fertile the amphidiploid will be. It’s probably safe to say that any of the above diploid species hybrids crossed with Rosa wichuriana will be a wide cross.
There is no reason of course why Rosa wichuriana can’t be incorporated directly into a breeding program with modern roses. It’s been done by Barbier, Walsh, Brownell and Moore. But judging by the success of the Kordes and Explorer Rosa kordesii cultivars, it’s not the way to go anymore. Certainly not for developing disease resistant roses in cold climates (Zone 3).
I believe the Barbier firm used R. luciae, and not R. wichuraiana. This was theorized by Graham Thomas in his Climbing Roses Old and New. They are closely related, but may not have the exact same effect in imparting disease resistance.
Perhaps one could try the Chevy Chase rambler.
I agree – as much as Rosa wichuraiana has been used, I think we’ve only scratched the surface as far as its potential is concerned. I have just recently started using this species, (actually the form Rosa wichuraiana poterifolia). I have five seedlings from the single-flowered Rosa moschata using wichuraiana pollen. Half of the seedlings seem to be mildew-susceptible; the others are very clean and healthy. I hope to see bloom in next year (and hope they’ll be fully-fertile). I’d like to use wichuraiana with some other species, just as you mentioned and then convert the hybrids to amphidiploidy.
P.S. I’ve been working on rebuilding and updating my website, but it could take me a while before it’s functioning. So, until then I’ve included the rough copy of the moschata X wichuraiana hybrids page for anyone interested in seeing the actual plants.
Have you tried Jersey Beauty? R. wichuraiana (pod) x Tea (pollen) makes it a bit of a short cut for me. I
I did once have a ‘Jersey Beauty’ but I’m pretty sure I’ve lost it. It could possibly still be alive amongst all the weeds. I never got to use it for any hybridizing. I do have a nice healthy plant of either ‘Gardenia’ or ‘Alberic Barbier’. I’ll have to check my old records to see which one it is. It’s a really nice once-blooming pale yellow fairly double wichuraiana climber. And I’ve noticed that it has set OP hips fairly regularly.
On a slightly different but related subject, I have a memory association of Baxter/Texas/bracteata. Are you that Baxter? If so, it might interest you that I’ve set hips on bracteata using wichuraiana pollen. Unfortunately the seedlings all die at the first true leaf stage. I’ve tried various ways to rescue them (with no success). I had imagined what unique and clean roses could come from that combination. I’m thinking that maybe one of the hybrid wichuraiana derivatives might combine with bracteata where pure wichuraiana has failed. Or maybe the reverse cross might be more successful.
And digressing a little more, I have sort of recreated the original Noisette cross (actually just analogous to the original). I used the single moschata and pollen from ‘Ducher’, an old white China. The resulting three seedlings are very healthy and vigorous with definite China traits, but are not reblooming. Actually, they haven’t bloomed at all yet, since they are only in their second year right now. I can hardly wait to see and smell.
Good Luck with your moschata crosses, Tom
I think that your Rosa moschata x R. wichuriana species hybrid is a significant achievement, and I look forward to your progress with it. I trust you will cross it with Rosa rugosa to increase hardiness while hopefully maintaining disease resistance. Since all three species are fragrant, fragrance should also able to be maintained.
I have always said that major improvements in roses will come about primarily by hybridizing species or near species, and then developing breeding lines from these hybrids. I cannot think of a better species to use than Rosa wichuriana, not only for disease resistance but also for developing roses that are relatively easy to propagate from softwood cuttings. This is especially important for rose growers in cold climates (Zone 3), where roses survive better on their own roots.
In the past I have primarily used Rosa wichuriana as a staminate parent, but I will use it as a pistillate parent when crossing with Rosa acicularis to produce tetraploid progeny. The goal is to develop a relatively hardy species hybrid Climber that is disease resistant with flexible canes and attractive foliage. I should point out that in this case it is important not to use just any Rosa acicularis, but genotypes that have superior vigour, foliage and flower colour. Fortunately they exist with Robert Erskine’s ‘Kinistino’ as perhaps the best example. Rosa acicularis supposedly has great ability to impart hardiness when crossing with other species or cultivars, and crossing with Rosa wichuriana will give us better knowledge how effective it is in this respect.
Paul, Basye’s Amphidiploid is related to more or less R. moschata. I have a very disease resistant seedling from it. I was lucky enough to obtain pollen from a single flower 2 years ago more or less, made several pollinations. But all of them were sort of weak, but one did survive. The pod parent was Abraham Darby. Its foilage is often distorted, for some odd reason, but they’re resistant and I believe it could be a nice plant when its older. I have a related seedling, a cross of 77-361 and Queen Elizabeth. I had hoped that it would be thornless, but it isn’t. But I kept it because of its clean foilage. My plan is to breed these to together and get some repeat blooming seedlings. Eventually I plan to breed it with some kind kordesii hybrid like William Baffin, or Scarlet Moss.
Regarding Graham Stuart Thomas stating that Barbier used Rosa luciae rather than the closely related Rosa wichuriana to develop his Ramblers like ‘Albertine’ and ‘Alberic Barbier’, according to the English rosarian Norman Young it was likely the latter species that was used. He points out that in the Botanical Magazine published in England, a picture of Rosa wichuriana was mislabelled Rosa luciae and apparently that is when the confusion began. Since both species are similar in appearance, grow in the same geographical area and have the same ploidy, I doubt that they are distinct species. No doubt some day a RAPD analysis will be done on these supposedly two different species and then we will know for sure.
I do not agree on the resemblance between R luciae and R Wichuraiana. They are two very dissimilar species when one takes into account the botanical characters (for example stipulate them or the type of inflorescence). In addition the representations of these species in “le journal des roses” confirms this dissimilarity.
R Wichuraiana A gives birth has sarmentous rose trees has small flowers in large inflorescences of the type ’ Dorothy perkins’ .
R luciae A gives birth has sarmentous large flowers in small bouquets of the type ’ Alberic barbier’ .