I’ve also noted that roses with pelargonin and cyanin tend to be brighter orange in cool weather or when they open in the shade. ‘Margo Koster’ is one example.
Floradora too, according to Yokoi. It has remarkable color in the right conditions. Probably the brightness variance is due to the contribution of the carotenes, which are labile to sun and heat.
Don,
‘Old Blush’, ‘Hermosa’ and similarly colored roses also tend to be clearer colored in cool weather. The purplish flush does not develop, just as it does not develop in ‘Margo Koster’.
Temperature can influence the ratio of pelargonin to cyanin:
Journal of Experimental Botany 25(4): 632-637. (1974)
Factors Determining Petal Colour of Baccara Roses III. Effect of the ratio between cyanin and pelargonin
I. Biran, M. Robinson and A. H. Halevy
"The changes in colour and in the pigment concentration of the two sides of Baccara rose petals which occur when plants are grown under various temperature regimes, were examined. The inner side of the petal is redder and the predominant pigment is pelargonin whereas the outer petal surface tends to ‘blue’, and, the predominant pigment on this side is cyanin. The cyanin: pelargonin ratio on the outer side of petals increased three-fold under the influence of low temperatures.
“The outer surface of petals growing for a long period under low tempertaures was ‘blue’ when compared with the red petals which had been subjected to low temperatures for a short period. The cyanin: pelargonin ratio of ‘blue’ petals was higher than that of red petals. Total pigment content was similar in both types of petal. Flowers grown under high temperatures ‘blued’ without a concomitant fall in the cyanin: pelargonin ratio.”
Marshall and Collicutt (1983) discussed some roses with increased peonin content.
Karl
We must take the “breaks” where we find them, which is one reason these old “dawgs” should be preserved, or at least documented with photographs that show just why they were so important. ‘Baby Chateau’ was a mystery to me until I saw Don’s picture. Wow! Now I get it.
When we read the parentage of modern roses, we so often see Award Winner x Award Winner, which may mislead novice breeders. It is often the “dawgs” like ‘Chateau de Clos Vougeot’ and ‘Rose Edouard’ and Moore’s ‘Zee’ that prove to be very important breeders despite their inherent weaknesses.
Would anyone cull a seedling rose suffering from mildew, rust and blackspot if it occasionally produced a bloom with sky blue highlights? That little puppy just might be the parent of a new family of roses. But if the amateur who raised it had read that diseased seedling should be discarded immediately …
Karl
It’s not my photo, it came from http://ruze.wi.cz. I felt the same way you did when I saw it.
if the amateur who raised it had read that diseased seedlings should be discarded immediately …
Well, Baby Chateau didn’t bring sky blue hightlights but it did bring something else, I think.
From Biology: The Dynamic Science, Volume 3:
“Normal plants have conical epidermal cells, with the tip of the cone pointing outward and giving the petals a velvety appearance. Epidermal cells of mixta have a flat, irregular surface that produces a dull appearance.”
This comment is in regard to snapdragon petals but the model should apply to roses and any other flowers.
It happens that conical cells in petals originate from the same cells that, in leaves, become trichomes and glandular trichomes (hairs). Now, mossing is a condition where these trichomes grow indeterminately, with a lot of branching. If the gene that causes mossing were to switch on in petals we might, theoretically, expect the luscious velvet we see in that photo of Baby Chateau ( and Chrysler Imperial, Papa Meilland, etc).
When we read the parentage of modern roses, we so often see Award Winner x Award Winner, which may mislead novice breeders. It is often the “dawgs” like ‘Chateau de Clos Vougeot’ and ‘Rose Edouard’ and Moore’s ‘Zee’ that prove to be very important breeders despite their inherent weaknesses.
I would agree with this, I did a cross (Baronne Ed Rothschild X Mme Caroline Testou) and kept two seedlings, one was named Overlander, the other looked like a real dog, but what it had, was very fertility as a seed parent, and when crossed with other Ht’s, produce really nice things with good health and vigour.
Warren,
You’ve hit on a recurring theme, that roses not worth introducing (for one reason or another) may be exceptional breeders. These are the “unnamed seedlings” that turn up with annoying frequency. Annoying, that is, to those of us who are trying to figure out ancestries.
John Cook (1905): “The best results have come from recrossing my own seedling.”
Alex. Dickson (1908): “Mildred Grant resulted from a seedling between Niphetos and Madame Willermoz in the first instance, crossed with a seedling of our own, which is not in commerce, and the system of which this is an instance applies pretty generally to all the better classes of roses introduced by us.”
Ralph Moore (1967): “I found that Zee (even though a rather weak plant itself and of pale pink color) was not only compatible as a pollen parent with many roses but that its range of usefulness was extraordinary.”
Sam McGredy (1969): “When selecting breeding material, it is not always the most promising seedling, as a variety in itself, that will produce a first class new rose, the seedling must be chosen for its promise in further hybridization. For instance, in a line of fifty red Hybrid Teas, three may be outstandingly attractive in appearance, but these are not necessarily the plants to select for breeding. One of these fifty could have a particular quality which has been recessive in previous breeding: so that is the plant to use.”
And this is especially true for roses with unique qualities or combinations of qualities, like the color of ‘Baby Chateau’ or the hardiness + rebloom of ‘Rose Edouard’.
Karl
Karl although it may be an unnamed seedling, I always list its breeding. There has been many a time when looking up linages and you see the unnamed seedling or undisclose, sometimes I just wonder if I am making the right choice when using them without knowing the linage.
That’s often my feeling, Warren. Who knows what evils you may be inviting in when you open those Pandora’s Boxes?
Kim what the old saying ( better the devil you know than the one you don’t)
Precisely!
Nothing ventured, nothing gained either.
I was wondering whether the traits that Baby Chateau bring to breeding come not from roxburghii but from foetida instead? According to HMF, foetida bicolour is one of Ami Quinard’s parents making BC a 4th generation foetida. Kim mentioned to me a while back that LeGrice thought good purple came from foetida and if you look at the photo of BC on HMF it has a definate purple cast to it of the same kind that my seedling from Alice Amos has which is also a 4th generation foetida:
[attachment 994 OPAliceAmos3.jpg]
Maybe roxburghii was used to induce dihaploidism in order to homogenise the foetida contribution that seems to be evident in the expression of the purple in an attempt to ensure good colour saturation and texture in future generations? The same purple cast can also be seen in the photos of Floradora on HMF though guess I that could be an artifact of digital photography.
Simon,
The “bluing” is apparently due to the presence of gallotannin, which forms a complex with cyanin. The same co-pigment is also found in ‘Reine des Violettes’ and other roses of similar color that have no Rosa foetida in their ancestry.
As I recall (I can’t find the source for this information), gallotannin adds a little more intensity to the yellow of R. foetida. This explains the mauve and purple tints found in the derivatives of R. foetida hybrids that LeGrice (1968) discussed.
Karl