I was wondering how many people have gone back to ‘Persian Yellow’ to try to get a more intense colored yellow flowers. Your hybrid Larry Carefree Copper is sure beautiful with the other key R. foetida selection ‘Austrian Copper’ with its warm undertones.
There is a nice paper on crossing Persian Yellow with white hybrid teas to get a new line of yellow started from R. foetida in modern roses and looking at the inheritance of yellow color. On the transmission of the yellow flower colour from Rosa foetida to recurrent flowering hybrid tea-roses | SpringerLink I met the authors at the rose research meetings in Germany in 2013 and unfortunately they said all their plants from that effort are lost. I really admire the cane hardiness of ‘Persian Yellow’ and its rich nonfading color. After last winter in the Twin Cities my two plants planted spring of 2013 in a slightly protected area flowered to the tip, while the modern shrubs in the area froze to the ground. In the past on the forum most others tended to feel like it wasn’t worth the effort going back to ‘Persian Yellow’. I’m just wondering how many people tried and if there was much success. I tried using it as a male a couple years ago from a plant I had access to at a public garden. There weren’t many anthers or pollen. I only had about 10 or so seeds and the couple seedlings that germinated didn’t look like hybrids and they bloomed right away. This year those two plants of ‘Persian Yellow’ produced a good amount of pollen and I used it primarily on ‘High Voltage’ and there are about 50 seeds. I sure hope some are hybrids. Hopefully there will eventually be some hybrids that combine good health, hardiness, and rich color.
On a side note, In the literature ‘Persian Yellow’ is listed as tetraploid. Since it is hard to get to take from root cuttings, I wasn’t able to get root tips to confirm its ploidy. Instead, I used actively growing cells in the shoot tip. It was more difficult, but eventually I got some cells that were able to be counted and it is triploid. I suppose that isn’t a surprise with its low fertility.
This is a great question, David, I hope there are folks out there who do use it especially against some of the more recent close-species hybrids. The closer your hybrid is to one of the species foetida’s the higher the pigment density and Larry’s Carefree Copper is indeed a good case in point and I’m using that as much as I can.
Your analysis that your Persian Yellow is triploid makes me wonder how you know for certain that your plant is actually Persian Yellow and not an imposter. I have been using pollen of Harrison’s Yellow (which is triploid) but have never even seen Persian Yellow so it would be pretty much impossible for me to tell the difference.
Thanks David for this thread. I follow all threads about yellow closely. It is a color that I am fascinated by. In your post you mention this part “I met the authors at the rose research meetings in Germany in 2013 and unfortunately they said all their plants from that effort are lost.”, Can I ask how you can loose the plants from just a couple of years ago ?
In 2011, to test the viability of ‘Persian Yellow’ pollen, I did several crosses with a Double Scotch (Spinosissima) rose. I had no success. However, because that was only a one time effort, that’s not to say such a cross couldn’t ever be successful, of course.
I very much like your ‘High Voltage’ x ‘Persian Yellow’ cross, and it sure will be interesting to see the results if you obtain seedlings from it.
I’m interested in OP seeds of Persian Yellow, if anybody has some to spare. The yellows I have been working with are Morning Has Broken, Shock Wave, Midas Touch and a cross out of Lady Hillingdon shrub variety.
That article was from 1978. Unless something really novel came of it, they probably would have let them go shortly after the study.
Tangential question- what color are the stigmas, styles, anthers and filaments on Persian Yellow? If you look at Austrian Copper and Austrian Yellow (or a yellow sport shoot on AC on HMF, you’ll notice red stigmas on AC but yellow on AY. Neither has any other red reproductive organs. Many modern yellows have red filaments or styles. Where from?
I guess I meant to say, for David Z., color of parts in YOUR version of Persian. I assume that’s the one in Lyndale Park, MPLS. (Or for anyone else with PY, what about your version?)
Ralph Moore said for years, if you want to see what colors are possible from a rose, look at ALL of its plant parts. Foliage, prickles, canes, flower parts, everything. Perhaps it’s more common for Foetida to pass on the red, whether it demonstrates it or not?
Hi Larry!! Great question!! Looking through my pictures I wasn’t able to find a good closeup of the pistils. The stigmas looked light colored and maybe there could be a bit of red on the style, but I couldn’t tell for sure from the pictures. Something that happens once in a while on some of the plants and some of the flowers of what are labeled as ‘Persian Yellow’ (source primarily Bailey Nurseries) is some red streaking. It seems like there is some capacity to make anthocyanins that may be suppressed. Attached is a picture of Persian Yellow with an open bloom of ‘Carefree Sunshine’ for color comparison.
I am hoping that my Persian Yellow blooms next year as I am very interested in trying my hand with it. I would also like to find a plant of the single version (Austrian Yellow) to see if it might be easier to work with too. I also purchased Lawrence Johnston (Souv. de Madame Eugene Verdier X Persian Yellow) in the hopes of using a direct descendent other than Soleil d’Or - unfortunately I don’t know yet what Lawrence Johnston might hold sine there are no listing of descendants and it has not bloomed for me yet.
Persian Yellow intrigues me. I somewhat feel sorry for it as I think that it has been given a bad rap because it seems mostly everyone seems to blame it for introducing BS into modern roses. But I see a lot of roses that predate the use of Persian Yellow that BS much more than Persian Yellow ever did. I personally think it is the source cross (Soleil d’Or - seedling of Antoine Ducher X PY) that continued the BS problem. I think that if a breeder would combine it with something very healthy and is known to pass on its good health we can get a plant much healthier and similar to Soleil d’Or. I think Larry demonstrated this with Carefree Copper as Carefree Beauty is healthy and passes on its good health. Austrian Copper, at least where I am, is on par with Persian Yellow when it comes to disease issues - maybe slightly better. From my stock, I would like to use PY on Carefree Beauty, Paloma Blanca, Prairie Princess, Knockout, Golden Fairy Tale, Golden Arctic, Pink princess, Folksinger and a few other phenomenally healthy varieties to see if I could in fact do this. Not only should these crosses produce healthy seedlings with Pernetiana colors, but they should be cold hardy for the most part, add that reblooming gene into the mix, and, hopefully, get the "modern: look to it. I also think that going this route should produce multiple lines of PY seedlings that can be used instead of the single line that our modern roses derive from with Soleil d’Or. Using multiple lines, in my mind, should give us more avenues to reach our goals - perhaps much quicker than it originally took. I’m no expert, but I think it is at least worth a shot.
Another idea floating in my head with PY is to create many more Hazeldean type seedlings. Hazeldean has a lot to offer breeders, but the big issue with it (other than the fact it is not readily available) is that it is not seed fertile. Fortunately it is pollen fertile but having a seed fertile variety makes it so much more useful to me in that I can theoretically double its use by using it both ways but, more importantly, I can also cross it with varieties that are also seed sterile (I wish I could do Hazeldean X Cinco de Mayo but neither produce hips readily enough.
I may be way off on my thinking with these two breeding ideas, but I am definitely willing to try them…once my PY starts blooming.
If I understand right, PY is really just a double of AC, or AY which amounts to the same thing. By now someone ought to be looking at AC to find out what kind of sterility it suffers. The pollen is fine. But I pollinated nearly a whole bush with Carefree Beauty, maybe in more than one season (several hundred flowers) and got one hip that germinated one (repeat-blooming) seedling that died within a year. As a source of yellow coloration all three donors may be equivalent. I’m becoming more convinced that it is not about the pathway to yellow color at all, but about regulators that allow full expression in specific stages of flower development.
I would not argue with Don that there are multiple shades of yellow produced by different carotenoids. However, the yellow pigment in a China rose may be the same as in Carefree Sunshine or Sunny KO, Harison’s Yellow and the 3 above. Just intensity that differs. We need find out this basic point.
Also, a fair number of deep yellow roses actually have some anthocyanin helping them along. A little more and they are orange. They fade to pink as the yellow goes away.
The only advantage of redoing the AC cross is to perhaps bring in some additional traits that we want, or are willing to tolerate, like having a shrubby look, instead of the classic bare stick greenhouse HT. If you just want the color genes, work with really good bushes of the color(s) you like.
Thanks you David for looking at your photos. On HMF it mostly looks like PY has yellow stigma, style, filaments and anthers. However there is of often an orangish shadow, and those Bailey bushes with definite anthocyanin on the petals. So I wonder what regulation is lurking there.
These are some pictures Michel took when we went on a picnic to the Minnesota Landscape Arboretum in June 2013. Two shots of Persian Yellow, one close-up of Austrian Copper. The colors really are Technicolor quality in person–you can see why rose hybridizers have been drawn to them for so long.
By the way, High Country Roses carries Austrian Copper. They are probably sold out now but usually have a new crop of all varieties coming along by early spring.
The size and number of chromoplasts (the carriers of carotene) also vary among species and varieties.
In addition, flavonols may contribute.
Chemistry and Biochemistry of Plant Pigments. (1976)
Chapter 16 - Functions of flavonoids in plants
J. B. Harborne
p 761
“(3) The common flavonols probably contribute to yellow flower colour when (a) they are methylated or (b) they are present in certain unusual glycosidic forms. Thus a myricetin dimethyl ether (syringetin) contributes yellow colour in the meadow pea Lathyrus pratensis, and isorhamnetin (quercetin 3’-methyl ether) may do the same in the common marigold Calendula officinalis. Quercitin 7- and 4’-glucosides have absorption spectra similar to quercetin itself and may therefore provide some yellow in gorse Ulex europeaus, in Rosa foetida and in other petals in which they occur.”
I had (but misplaced) an article on the interaction between the quercitin derivative and the carotenes. The carotenes have two peaks of reflectance in the yellow range. The quercitin derivative reflects only a little yellow light, but the peak fits neatly between those two carotene peaks. Thus, the quercitin contributes much more to the depth of color than we might guess from seeing it alone.
“The assumption that the yellow pigmentation of rose petals is due to flavonol glycosides has persisted up to the present day. It is only since 1963 that qualitative tests (solubility in ether, blue staining with SbCl, etc.) have led to the proposal that carotenoids are present…In fact, all rose flowers, including yellow ones, contain quite a lot of flavonoids. However, only when they are present in high concentrations, together with carotenoids, do they contribute to visible absorption, giving rise to a bronze color. This has been proven experimentally for ‘William Allen Richardson’ (Ducher, 1878) and ‘Whisky Mac’ (Tuntuu, 1967) whose flowers are brownish yellow.”
Eugster and Marki-Fischer, The chemistry of rose pigments, Angew. Chem. Inr Ed. Engl. 30 (1991) 654-672.
Samiei, et al. (Genetic diversity and genetic similarities between Iranian rose species. Journal of Horticultural Science & Biotechnology (2010) 85 (3) 231–237.) List the chromosome numbers of numerous species. The two accessions of Rosa foetida (double) were found to be tetraploid, along with all the other R. foetida accessions (lutea and bicolor).
Thanks for that reference Karl. I think I saw it and want to access it again. Maybe this double one sold as ‘Persian Yellow’ and their double yellow one(s) are different genotypes. I am interested in if they used cytology to document chromosome number or flow cytometry. Flow cytometry is indirect and can lead to inaccurate estimates of ploidy.
I purchased a plant of R. foetida from Canadian Tire this summer. (It was labeled as ‘Persian Yellow’). It made a large number of hips. I tried several pollinations and it set seed only with Prairie Peace. Doug Wild attempted extractions from seeds I sent him and there were no embryos. The results were disappointing.
