155-10-01: Roxburghii, are you in there??

For years there has been much discussion about the pedigree of a number of roses that list the species R. roxburghii as a parent. The Tantau Floribunda 'Floradora' (1944, Germany), for example, lists 'Baby Château' as the seed parent and R. roxburghii as the pollen parent.

Now, at a glance, there isn't the slightest hint of the species parent in the look of 'Floradora', which has led many to doubt its listed parentage. I myself doubted Tantau's pedigree for the longest time, at least unbtil I had some experience in using certain species and near-species hybrids in breeding, especially when they were employed as pollen parents. Let me elaborate.

I frequently use certain seed parents in making crosses that might be impossible on many other parents. After a while, you start to recognize which of your seed parents are likely to be "door openers" when planning iffy crosses. Introducing certain species can be especially difficult; sometimes the chromosome counts don't match, or the two varieties are simply too distant from one another in the family. I believe there are other unknown factors that play a role in fertility. Whatever the case, I found that even when using very willing seed parents, certain pollens would result in seed that, once germinated, turned out to be the result of apomixis*.

Apomixis is what happens when pollen initiates the fertilization response in a plant, but once the pollen tubes grow into the ovary, the genes prove unusable. So, in an effort to salvage the seed making process, the plant instead duplicates its own genes, in effect cloning itself. In roses, I suspect there is some recombinant action occurring as well, since some of the individuals arising from such crosses are not identical to the parent plant, but appear to be highly similar. In some cases undoubtedly some selfing may also occur, perhaps the result of insect activity, or simply incomplete emasculation.

The seedling you see pictured here was an experiment designed to see what happens when a (supposed) second generation R. roxburghii hybrid (in this instance, Moore's 0-47-19 was used) was crossed once again with the species R. roxburghii. And so, what we have here is:

[R. wichurana X ('Baby Château' X R. roxburghii)] X R. roxburghii normalis. Clearly, assuming the Tantau parentage is correct, we have a lot of species genes in this plant. Now, when I made this cross I expected one of three possible scenarios: total rejection of the pollen, apomixis, or self-pollination by insect vectors. As it happens, I got only a few hips from the 40 plus pollinations, leading me to believe they were likely the result if insect fiddling. From the approximately 20 seeds I sowed I got two seedlings. The one illustrated here is the healthier of the two; the other is far less vigorous, but it is trying to build up steam. (Maybe our cold, prolonged spring isn't to its liking; I know its not making me feel great!)

Until this individual reached a certain size I was unwilling to make many assumptions about its pedigree. But now, I look at it and I come to the conclusion that this is actually, for real, a R. roxburghii hybrid. Look closely: the most recent leaves are now composed of nine leaflets, surely a sign that roxburghii is influencing its development. I don't expect to see flowers this year, which is fine. Right now I am just fascinated to see its vegetative development. I doubt this is any kind of proof of the presence of R. roxburghii in its ancestor, 'Floradora', but it does show that when using the species, the resulting seedlings can show clear evidence of roxburghii traits. Fascinating.

*For more on apomixis, see the Wikipedia article here.

170-09-02

17-09-02 = R. arkansana X 'Carlin's Rhythm'.

I'm determined to obtain a seedling from the delicate-looking-but-unbelievably-tough R. arkansana, a North American native. The species has richly scented single candy pink blooms, and certain select clones sometimes have subtle stripes or streaks of darker color on the petals. Mine doesn't, but mine does do something I hope to capitalize on; it blooms at least three times in the growing season: late May, again in July or early Augustm then again in late September or October.

My specimen of R. arkansana is a reluctant seed setter, rarely accepting pollen from anything but itself. However, I did manage to get two seedlings from a cross using Kim Rupert's beautiful 'Carlin's Rhythm'. This is the second of the two (the first was paler and not as nice) and displays large-ish blooms (about 2.5") in a deeper than average rose pink. The scent is rich and pure "old rose". Now, the trick is to try it in breeding to see if I can make the next step. It will have one copy of the modern hybrid remontancy gene, and at least once copy of the gene that makes my arkansana repeat, which may or may not be distinct from other forms of remontancy. As both parents are (at least in principle) tetraploids, I would expect this seedling to be a tetraploid also.

220-09-02

Apparently the striping is a fixed trait; the next bloom to open is identical. Excellent.

220-09-02

220-09-02: "A supposed tetraploid form of R. rugosa" X Basye's Blueberry.

The seed parent is a rose shared with me by Joan Monteith about a decade ago. Joan did an experiment in which she treated a select form of R. rugosa with the chemical Colchicine with the hopes of doubling the plant's gene count from 2X to 4X, making it more compatible with most modern tetraploid hybrids. It has not been determined with any certainty that this Rugosa is in fact a Colchicine-induced tetraploid; measurements of pollen diameter has been inconclusive. However, I have pursued breeding concepts that presume it a tetraploid and I will simply evaluate the results as I proceed.

Case in point; today's seedling. 220-09-02 is the first seedling from this "presumed tetra Rugosa" X 'Basye's Blueberry' cross. Of the dozen or so seedlings I got from the cross, remarkably not a one has the classic Rugosa foliage. In fact, most all lean heavily towards the look of the Basye parent, which comes as a huge surprise. (Most R. rugosa hybrids in the first generation show strong Rugosa influence, often obliterating all of the other parent's qualities)

The flower is small, at just under 2", quite heavily Clove-scented, thick of petal and most remarkably, each petal has a strong white streak down the middle. Don't ask me where this trait came from. I do know that Ralph Moore once showed me a Rugosa hybrid with about 15 petals that showed the same petal streak, and it was striking. Pollen has been gathered from this seedling and will be placed on a number of tetraploid seed parents I have assigned for the purpose of testing pollen fertility. In the meantime, I look forward to evaluating this plant for sturdiness and disease resistance. I am hopeful, given its pedigree, that Blackspot resistance might be superb.

165-09-03

165-09-03: another approach to working with R. foliolosa. Click on the photo to view a larger version.

A few days ago I mentioned 44-09-13, one of my Foliolosa/Therese Bugnet hybrids. In the case of 44-09-13, the seed parent was a second generation R. foliolosa hybrid, whereas with today's seedling, 165-09-03, R. foliolosa itself plays that role. Both crosses utilize Therese Bugnet as the pollen donor. The idea was simply to make some Therese Bugnet crosses using any/all diploids I had on hand and which I knew to be decent seed bearers. The R. foliolosa approach was, to me, particularly appealing since it was such a healthy, Winter hardy individual. R. foliolosa also imparts on its progeny Fall foliage coloring to make the most dramatic of Maples and Sumacs envious; fiery oranges, yellows overlaid with flame red. I have come to think that modern roses ought to have some degree of "four season appeal".

I consider the seedling pictured here to be pretty much intermediate between its parents, although the flower itself leans more towards Therese Bugnet in size and petal count. The bloom has a moderately intense Rugosa scent; a welcome trait, to be sure. (The weather has been abysmally cold this Spring, so maybe when/if it warms up, the fragrance will be more intense.) The foliage could easily be said to resemble either parent, since both have fern-like feathery foliage that is narrow of leaflet and pleasantly matte in texture.

Pollen has been collected from both this seedling and its relative, 44-09-13, to be tested for fertility this year. I will try to limit myself to working it on other diploids and maybe a triploid or two, but I might just dust a few blooms of Midnight Blue while I'm at it. I won't let the creation of triploids (and their potential for sterility) stop me from making a cross once I have a few foundation plants established in the confines of a given ploidy. As Ralph so often said, "The rose will find a way."

44-09-13

44-09-13 = (R. foliolosa X 'Little Chief') X 'Therese Bugnet'

This is the first of this group of seedlings to bloom. Hardly an exciting flower, really, but not a surprising result, really, considering how significant a role R. rugosa plays in its pedigree. The fragrance, in fact, is pure Rugosa: richly Clove-like. The foliage is pure 'Therese Bugnet'; ferny, with narrow leaflets, and that odd matte texture. The foliage has been impermeable to the standard diseases so far, but testing in earnest for Blackspot won't happen till the selections are planted out in the open garden.

For now, I am collecting pollen from some of these selections to test as breeders. I don't consider these individuals as "finished" works, but as potential stepping stones towards improved cold climate-friendly plants.

You can view info about the seed parent here.

121-06-14: impressions in year five.

Breeding roses is not a game for the "instant gratification" crowd. Patience, for us, is not a virtue, it is a requirement.

Cross #121-06 was created in Spring 2006; that is when I selected pollen from Austin's 'Tradescant' and placed it on blooms of my own seedling, 174-02-17 ('Sheri Anne' X 'Out of Yesteryear'). The foloowing year, probably April 2007, this seedling first appeared in a tray of seed mix topped with a generous layer of Perlite (for Damping Off suppression, did you know?) Although I do not have any notes to indicate when I first saw it flower, chances are it bloomed for the first time in June or July of 2007. The first bloom probably did little more than hint at bloom color and form, but apparently it was enough to make me select it for potting on for further observation.

In later Winter 2008, however, this seedling was almost destroyed by a week's worth of hard freezes that went down into the low teens every night. It was still in a 5 gallon container and rose roots don't like freezing solid while in pots. Long story short, it did survive, although it took more than a year to recover its vigor. 2010 showed me what a potential jewel this seedling was, with its deep garnet/purple swirls of petals, reminding me sometimes of 'Charles de Mills' or some such anachronistic creature. But unlike its Gallic brethren, this lad blooms in flushes through the growing season; pretty much a requirement for modern hybrids. (Although I am often found arguing for the merits of the elegant once bloomers)

I'm not done passing judgement on this seedling; it has yet to tell me much about ease of propagation, or its ultimate disease resistance out in the open test bed. It isn't yet as big as it will get when fully matured, and so I need to be quite sure this dark Swan doesn't turn rabid in year 6 or 7 and produce all manner of rank growth, breaking from its compact grace and going all "Audrey" on me. Time, as they say, will tell.

Midnight Blue, just because.

I was documenting seedlings in "number four" yesterday and took the opportunity to photograph one of my favorite moderns, 'Midnight Blue', by Tom Carruth. Echoing a recent comment by Jim Sproul, it is one of the few named varieties I still use in breeding. (I mostly use my own proprietary hybrids nowadays)

'Midnight Blue' is a truly amazing shrub. What color! It is also a very willing and capable seed/pollen parent; it is one of the few roses I can expect consistently good numbers of fertile seeds from, regardless of what the pollen parent placed on it.

Busy day, off to work!

Proving fertility of the R. fedtschenkoana hybrids.

A few years back, Kim Rupert graciously shared with me one of his experimental hybrids, 'Orangeade' X R. fedtschenkoana, a white flowered species-like hybrid designed to be used as a breeder plant. It took a while for my plant to settle into its invironment, but settle in it did! It is now a thicket (ever-spreading, I might add) about 8 feet across and 10 feet high. Contrary to expectations for such a cross, it does rebloom, although only modestly. Mine does not set seed, but offers potently fertile pollen.

The cross 54-08, made in 2008, combined this fedtschenkoana hybrid with 'Midnight Blue', a marvelous Carruth hybrid with a deliciously mixed pedigree. (I look at hybrids with widely varied genetic backgrounds as an indicator of potential health and vigor; stirring the same old pot of genes is deadly)

54-08-03 was one of the first of about ten seedlings to bloom, and one of about four that I have selected for further breeding. Blooms are actually more lavender than they appear in photos. I recently germinated the first seedlings of crosses using this seedling, and some of its siblings. I don't know where this breeding line is going to end up taking me, but the R. fedtschenkoana genes are proving to be capable of imparting unique foliage, architecture and vigor traits to offspring. Seedlings also tend to hold on to the unusual "linseed oil" scent of the species parent. Not everyone is going to appreciate this fragrance, but I like its uniqueness. The foliage also tends to have a Pine-Cedar scent to it.

Busy day ahead; breeding has begun in earnest in the past 24 hours, as the main stud house explodes into bloom. I must go attend!

L83 in bloom

L83, the AgCan Kordesii breeder is in bloom now. Pollen available upon request, for the hybridizers reading this.