Hi everyone,
I have a question about the 4 China studs, the 4 roses that came from China and are said to be responssible for the reblooming qualities of a lot (not all though) of our garden roses.
Does anyone of you grow them, and, are they prune to blackspot? Could it be that together with the reblooming, or should I say the abscence of not-repeating, qualities came the susceptibility to blackspot?
What are your thoughts about this?
A bit more info about these roses: https://www.google.be/url?sa=t&source=web&rct=j&url=http://www.rose.org/wp-content/uploads/2012/01/History-of-Roses-China-Roses-Part-One.pdf&ved=0ahUKEwiBhqWhuo7WAhUJfFAKHe6iANkQFghIMAo&usg=AFQjCNEG3DpxQT1yb58glf-SR3eIZZ-L1w
I would be inclined to say no. Though they are not immune to such, they are rather tolerant, and I don’t think one can paint this picture with such a broad brush. Blackspot is a disease of wetter areas, and the conventional wisdom suggests that roses from more arid climates, when introduced into the roses being grown in e.g. Europe, might have contributed. I’m speaking predominantly of Foetida, which gave the roses true yellow colors. But it’s also likely, it seems to me, that different species have different mechanisms for coping with disease, and that hybridization, while it might combine mechanisms, also has a greater potential to dilute any one mechanism. There are chinas and teas that have earned Earth Kind status in the gulf coast area – a location with high BS pressures.
In the past, I strongly have recommended Bonavista, Elmira, and Moncton as starting points for breeding with China roses (they are hybrids with rugosas).
http://rosebreeders.org/forum/search.php?keywords=bonavista
Hopefully, Paul Barden will see this and add his experiences. Previously he has posted that when China genes were added to otherwise healthy roses of his breeding, black spot became issues.
Before we blame the Chinas, remember it’s a two-way street. One could also say that when European genes were introduced to Chinas and Teas, blackspot was the result. It’s probably a case of different forms of resistance being broken down in the F1. Here in New Jersey, my Chinas and Teas are as a whole barely affected by blackspot, followed closely by my Polyanthas. But one of my cleanest roses of all is one particular Bourbon – ‘Souvenir de Victor Landeau’. The only fungicide I use is a mix of potassium bicarbonate, neem, and Dr. Bronner’s soap, mixed in a hose-end sprayer. But that is really just for clearing mildew outbreaks in Spring – it doesn’t do much against blackspot here.
~Christopher
I grow Old Blush and you might be on to something,
The rose genome is very complex, and their antagonists are likely equally diverse. Having said that, I’ve been through hundreds and hundreds of cultivars in my climate, (Texas Gulf Coast), and Old Blush is one that I’ve always kept.
I am a no spray, tough love, rose torturer, and in my location, with regard to blackspot, Old Blush is as good as Carefree Beauty, and better than all of the KO’s, except the original and the double. Jersey Beauty is very resistant, and Blush Noisette is superior to all - two more old gene combos.
And of course, lots of the Teas do quite well here.
However, none are impervious. Some tolerate my local strains of BS much, much, more than others. it’s all a matter of degree.
Equally, rugosas are pitiful here, and most modern roses, including those of the last twenty years, are practically leafless by this time of year without any help.
So as bad as I hate to admit it, in capturing those repeating genes, we may have indeed brought along some genes that weren’t up to snuff for the fungi in different climates. It’s beyond me, but I do enjoy the quest!
Baxter
Hi,
it is just something I was wondering about. But as some of you suggested, it might be due to the combination of the two. The Chinas were probably happy in their own climate but probably not ready to ‘fight’ the harsh, cold and moist environment of Europe? Although, honestly, I have no idea what the weather in China might be, I imagine there are places overthere where it is very moist, damp and cold as well, but maybe that are not the places where these roses had their origin.
Also, ploidy… as it seems that the four stud China’s were all diploid. Meaning there progeny only inherited 1 set of 7 chromosomes. So from the moment some genes that were needed to fight funghi were not passed on, the problem would inevitably arise?
Still, I believe this is an interesting topic. In the past I read that all the problems with the hybrid teas where due to R. foetida, but I have the “persian yellow” in my shady garden, and although she refuses to flower for me, she was quite healty for the first 3/4 of the summer. After that, she lost her leaves as well, but I believe that was not really due to blackspot but due to the severe drought we had in the first part of the summer.
‘Slater’s Crimson China’ is triploid, as are some other old red Chinas – but not all. For example, ‘Miss Lowe’s Variety’ is diploid. A little while back, I happened upon a genetic study which included checking the ploidy of the roses examined, and I added that reference to those roses on HelpMeFind. Look up some old red Chinas and you’ll see which ones were tagged triploid by that reference.
Admittedly this reference is old, but Dr. C. C. Hurst found that the triploid red Chinas he observed would produce haploid pollen and diploid ovules. This means that if they were fertilized by tetraploid roses, such as the once-blooming European old roses, the offspring would be tetraploid. I think this may be why the few fertile Hybrid Chinas were red, rather than pink – they descended from triploid red Chinas rather than diploid pink Chinas. For example, ‘Malton’ is tetraploid.
~Christopher
Thx for correcting that Christopher.
I had my reference from an old paper by
de Vries and Dubois from the Second International Symposium on Roses, where they mention the “four diploid ‘Stud’ China’s”. http://edepot.wur.nl/24387
That is why I thought them to be diploid. In their table 2, after Stewart, 1969, they state that the tea china, the pink china are diploid. The hybrid china woukd according to them be tri or tetraploid. But I guess all this information might be out of date… Anyone who knows a good paper where the right family tree of tge rose can be found? Or will this always be some kind of a guess?
We’ve been in contact with Dr. Guoliang Wang about old chinaroses.
See here: Kategorie:China-Heritage – Rose-Biblio
Many greetings
Rolf
Thx for the info! Seems a very interesting, although a bit expensive book.