Monday, May 18, 2009

Bracteata line breeding.

It seems to me that line breeding is rarely pursued in the breeding of roses. In part, I expect this is because undesirable recessives start to show up and loss of hybrid vigor becomes an issue as well. Still, many of the Canadian Explorer roses rely heavily on line breeding, making extensive use of the 'Red Dawn' X 'Suzanne' line and the 'Kordesii' line, and with great success.

Well, I have been working with the Moore line of Hybrid Bracteatas for several years now and it has become very clear that the biggest battle with these is getting decent color out of them. Ralph Moore's most attractive hybrid of the group (for me) is 'Out of Yesteryear', whose parentage is 'Sequoia Gold' X 'Muriel'. 'Muriel' is Moore's first successful cross using R. bracteata (crossed with 'Guinee') that was fully fertile and able to carry forward the line. 'Muriel' is a tetraploid, as is 'Sequoia Gold', but when these two were crossed, 'Out of Yesteryear' resulted and it turned out to be a triploid! How two tetraploids mated to produce a triploid is a bit of a mystery, but there you have it. Even more interesting, 'Out of Yesteryear' is a fully fertile triploid, contrary to the mytholgy of triploids being infertile. You can use its pollen on pretty much anything and get loads of seedlings from it.

I've done plenty of crosses with 'Out of Yesteryear' over the years and there are some excellent traits it passes on, and some not so great ones. Its offsrping tend to have excellent vigor, beautiful foliage and often very beautiful blooms packed with petals. Many are often fragrant as well. However, seedlings can be very thorny, the petal texture too thin and rarely do you get anything with strong coloring. Many seedlings are just white. So when I get a seedling that has decent color, I'm inclined to explore it as a stepping stone towards Bracteata hybrids with good color, which leads me to these two.

174-02-17 = 'Sheri Anne' X 'Out of Yesteryear'. One of its siblings tested as a tetraploid and I suspect this is also. It is a thorny plant that is more horizontal than vertical, with smallish glossy foliage. It blooms at many nodes along the previous season's canes and can bloom in large clusters sometimes. Blooms have a vaguely HT shape when in bud (see photo) but open to a flat 2.5 inch shape. Color is a medium red in bud, fading to a pale red/pink. It sets seed with most any pollen, but seed fertility is low at about 10-20%. However, when it does produce seedlings, a high percentage of them has something about them that warrants further evaluation. Offspring tend to bloom in big clusters with compact, graceful architecture and good color. One of my favorite new shrubs came from a cross of 174-02-17 X 'Hot Cocoa'. (More about this soon)

33-03-03 = 'Twilight Skies' X 'Muriel'. Why, you might ask, did I select the mauve miniature 'Twilight Skies' as the parent for this cross? Because it was there! I had grown it for two years when it was new and it set seed readily, bloomed like mad, so I thought why not? It was untested and might have qualities that would make it worthwhile as a parent. The seedlings from this group were mostly lavender/pinks with one coral colored one in the mix. Several were grown for two years and all but 33-03-03 were discarded for poor vigor or unattractive blooms. 33-03-03 is a semi-climbing plant with dark green glossy foliage and 2.5" medium red blooms that fade to a reddish pink with age, about 25 petals, cupped in form. It blooms in clusters all along the arching canes, repeating in flushes through the year. David Zlesak kindly did ploidy tests on some of my Bracteata seedlings for an article we were co-authoring*, a few years back and it turns out that 33-03-03 is a tetraploid. It is fertile in both directions and should be compatible with most other tetraploids.

174-02-17 and 33-03-03 happen to be growing side by side in one of the greenhouses, both descended from R. bracteata through 'Muriel', and both were selected for their relatively strong coloring. Yet it never occurred to me to cross the two together....until now. The idea (and hope) here is that some of the more interesting Bracteata traits might be reenforced while retaining the vigor, repeat blooming habit and red coloring of each. Anything could happen of course. I might end up with a load of diseased seedlings with no vigor and no rebloom. Its possible the seeds might not even germinate, assuming I get seeds at all! We shall see.

*See: Bracteata Gene Counts Article

5 comments:

  1. What do you think of the idea of trying to replicate, in kind, the original crosses Mr Moore did to make 'Muriel' by crossing straight bracteata with 'Ebb Tide' given we can't get 'Muriel' or 'Out of Yesteryear" here? I have ordered 'Many Happy Returns', which is a descendant of 'Mermaid', to use as well and have also ordered straight bracteata.

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  2. Simon,
    Good question. From what I recall about Ralph's conversations about the origin of 'Muriel', he made many, many crosses before he got any hybrid seedlings at all, and 'Muriel' was the first one that was fertile. I think that going back to R. bracteata is reinventing the wheel and likely to be a lot of work to get a fertile seedling to move forward with, unless you breed close to its own group. I believe Viru has done work with R. bracteata crossing it with R. clinophylla etc, and those are fertile. I expect that trying to cross R. bracteata with modern HT's and Floribundas will take you down teh same difficult road Ralph took years ago. But hey, you may be pleasantly surprised.

    You are in Australia, is that right? Too bad mailing pollen is discouraged by the authorities. :-(

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  3. Yep... in Australia... I'm actually allowed to import seeds of roses so I might go down that path one day instead... was thinking of contacting Jim Sproul to see if I could buy some hulthemia seeds off him at some stage so I could start a line of these here too. One would think that if seeds were allowed then so should pollen *shrugs* Anyway... talking with Viru he has had interest in getting his hybrids into Australia but nothing firm yet. He was thinking it could be many many years before these plans came to fruition. So... reinventing the wheel might be the only reasonable option. Viru has offered to send me seeds of clinophylla in the future and I will take him up on this. Clinophylla is here, growing in the Adelaide Botanical Gardens, but they are still in the process of properly classifying it and won't be releasing propagating material for a while yet.

    When you say My Moore did many many crosses before he got any hybrids at all... do you mean that he got seedlings but they were true-to-type bracteata and so selfs? Or, do you mean that nothing took and no seedlings were produced?

    One of the things I was thinking about was using Teas and ground cover/wichurana-type roses with bracteata instead of HT or Floribunda to try for better architecture and overall suitability for gardens... that's the plan with gigantea too as well as having a crack at using laevigata with Teas.

    As you know, Viru recommended 'Many Happy Returns' so will also see how that goes with Teas as well. It's listed as a ground cover rose here so am hoping for some shrubby typed plants out of it and the Teas. If I get results anywhere near as nice as these ones of yours I'll be stoked :)

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  4. Simon,
    Did you look at yesterday's post about 119-06-01? This is my best shrub from the Bracteata breeding line so far.

    My understanding about Ralph's early work with R. bracteata is this: many crosses were made with numerous modern hybrids and very few crosses resulted in any seeds at all. Of the seeds that did germinate, few survived for long or were culled because of health issues. Of the few that remained (VERY few), 'Muriel' was the only one that proved fertile and able to move the Bracteata line forward.

    If I had to reinvent this wheel, I would avoid modern HT's and Floribundas as the starting point and work with roses like what you have suggested. I might even try 'Orangeade' with R. bracteata just because 'Orangeade' seems to be able to create a fertility link with almost anything. I have found that the Teas (not HTs) have limited fertility and so I'd be careful about selecting one of those for breeding. The Teas rarely impart strong coloring to offspring either, which will be an issue when starting with R. bracteata. I'd pick a groundcover type rose in a strong color to start with if I were you. The Meilland groundcovers might be a good choice, or maybe something like 'Robin Hood'? R. bracteata also seems to have an affinity for R. rugosa as well. Just a thought....

    Good luck!
    (Email me if you care to give me a mailing address....we'll see what we might be able to arrange.... paul at agora dot rdrop dot com )

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  5. oooooer... rugosa huh... that's an awesome idea... will give that one a go for sure :) Thanks for that tip! Yes saw 119-06-01... very beautiful.

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