What happened to deciduous x evergreen Azalea hybrids created in the mid 2000s?

[Rivian]

And maybe even decades earlier.

There are a number of articles from that time on researchgate in which, often, dozens of vigorous enough, non albino seedlings were obtained. (like Kurume x Rhododendron flavum f. flavum, which worked rather well depending on the specific Kurume parent)

Yet to this day no yellow evergreen azalea exists on the market as far as I'm aware. (Maybe other successes?)

Are the studies just for theory and they throw the plants away after publication? (half serious)

I didnt really come across follow up. Its like a big cliffhanger.

 

[Glaucus]

Pretty sure you are asking me. There's about 5 scientific papers about different theories regarding yellow pigmentation. But the thing here to understand is that these scientists are paid to publish papers. Not to produce commercial varieties.
And the scientists study what the grand money allows them to study. Together maybe with interest of students, possibly. I don't know which names that pop up.

So in terms what happened to the actual plants, I have no idea. Very possible that they were discarded after the research finished. This sounds as bit silly, but that is often how academia works.
There's no cultivar registered that directly flow out of this type of research. Or a plant or two could still sit in some greenhouse. Someone might have decided to save some plants for long term. I never did research with plants. But I can see that maybe they have permanent staff/technician/gardener around that will save some old stuff for future generations when research lines dry up and professors retire. But likely stuff gets thrown away all the time.
The closest are Senbazuru and Oryu which might be based on some of the ideas explored in those papers. I am not aware of a commercial company behind new satsuki cultivar. It's just hobbyists. Only for 'Oryu' a big horticulture corporation filed a patent in Japan and the US. But in the US they never did anything with it.
I found it actually surprising that even among the amateurs who compete to create new satsuki cultivar, there is nothing yet building on either Oryu or Senbazuru.
The newest pale yellow is actually 'Okasui' but I have seen it and there is barely any shine or yellow. It just seems white.

I think though that with the vast amount of new varieties coming from the satsuki community in Japan, we can't really complain.


In the same way in the US there's azalea researchers like Kehr and Pryor who back in the in the 60's and 70's did research and made crosses for years or maybe decades, and it seems their plants largely are no longer around.

So based on the poor results from skilled people in the past, I'd not recommend people to try to put too much time and energy into this. Intergroup hybrids in general, but yellow evergreens specifically.

 

[Rivian]

Pretty sure you are asking me.

I have a habit of posting questions here that I really should be asking in the Maple or Rhododendron Society forums, despite that usually resulting in no answer on B-nut.
I did figure you're the most likely to have insights on this tough. I appreciate you taking the time.

Very possible that they were discarded after the research finished.

I had a hunch...

You'd think that those who commissioned the studies and saw reasonable success, without embryo rescue, would then use the lessons learned for a larger, commercial breeding effort and end up putting lots of plants in a greenhouse or test field. So it seems weirder that nothing came out of that, rather than the small scale of the studies.
I can only guess the studies were not done to really reach those goal plants (by themselves or follow up breeding), but maybe just to level up academic ranks. Or there were bigger piles of money to be made from breeding other things.

 

[Glaucus]

It's not about people making piles of money. Probably, these people are plant scientists who spend part of their career on rhododendron indicum and similar. And since these are native species to Japan and they are horticultural relevant, there's academic incentives to do research on them. There's a few professors in Japan who during the years did some research on satsuki and other evergreen azaleas. Not sure what they spend most of their careers on.
But since there is a group in Belgium doing research on evergreen azaleas, one in Italy, one in Vietnam, one in Taiwan, and a couple in China, they have got the needed citations of their papers.
So that's the main incentive. They contributed to the knowledge. They did I believe eight papers on the evergreen x R. japonicum hybrids and they got 30, 24, 56, 37, 38, 26 and 21 citations, or something like that.
The albinism observed in these specific hybrids is apparently a wider phenomenon for all wide hybrids and the relationship between chromosomal and plastid DNA is relevant for plant evolution in general.

There's a handful of people worldwide who have read these papers and are doing wide crosses in the rhododendron genus.
In fact, we are discussing this paper right now in 2023 on a bonsai discussion board. So that proves the relevance, in a way. Even though no new cultivars seemed to have been produced.

Oryu was produced by Masao Oide who registered a ton of other satsuki cultivars. If you look at your dictionary and scan for 大出昌男 in the leftmost column, you see his name a lot.
I believe is an amateur enthusiast and not a researcher or a professional grower. But if you research him, there's a video of him walking through a garden in autumn. But nothing about satsuki. So maybe he had his hands in many things.
His patent for Oryu in the US was with Suntory Flowers Ltd. But they don't seem to sell satsuki. At least not at the moment. And certainly not in the US.

Senbazuru was done by 黒相惇 which should be Jun Kurosou. Doesn't appear in the resaerch papers either.

I mention both because both were products of deliberate hybridization where the parent plants were never registered and because both are yellowish following the theory that a certain mutation prevents yellow colours from disappearing. And the long-lasting flower mutation prevents both choloroplast and chromoplast pigments, namely chlorophyll and carotenoids, from being broken down.
And the grandparent of Oryu is R. macrosepalum 'Kocho-zoroi', which is mentioned in the research papers. And it has the same mutation as Chojuho, and thus also Senbazuru.
So one theory why Oryu is more yellowish is that it doesn't break down all pigmentation (either carotenoids of flavonoids) that would be present in leaves but not in flower petals.
But there's no actual research paper on Oryu and no direct links I know between the people that did the research and the people that registered these two cultivars. But that's the closest link I know of. Could very well that these people were talking to each other or knew of the research.

But no hybrids between Rhododendron japonicum f. flavum and evergreen azaleas that I know of. That said, it maybe wouldn't appear in the satsuki dictionary. But Oryu kinda ought not to be included there either, I would say.
So I can't say for sure that no such plant was ever registered and produced in Japan. Say as a kurume type. I am not really aware of what is going on in the kurume-section in Japan.
I just spoke to a woman last week who told me she had been to Kurume to visit the azalea nursery at the kurume research centre there, and that there wasn't a lot going on. And that it seemed that most of it was shut down.
There is a big decline that has happened in Japan for both satuski and other azaleas like kurume. In part because of the aging population and because of the shift to other hobbies and interests.

 

[Glaucus]

There's actually papers from Kenji Ureshino from 2016 and 2019, so they could still be working on this subject. But his most recent paper is from 2022 on eggplant hybrid fertility.
You could even try to email him and ask him questions about their research. That's what contact info of the PI is for.

The point of academic research is to produce knowledge useful for other scientists. If you are doing plant breeding for a commercial company, you would keep everything secret and only release your plant.
It is of course very nice if research serves all purposes, both academic and commercial, and is immediately applied and useful and productive. But almost all research doesn't work this way.
In fact, it can be very annoying to try to find a direct application or get funding from private industry. Of course, in plant breeding it is more straightforward how this would work.

People like Kehr and Pryor, they neither produced plants (that lasted with commercial success) or academic papers. Just ARS/ASA articles.