Tuesday, June 7, 2011

87-09-01, an update

Pictured here is 87-09-01, a seedling from the 2009 cross of two species; R. soulieana and R. foliolosa. Both of my specimens are, I presume, diploids, and so I expect my seedlings are also. The cross was made with the idea of combining two very hardy, very healthy species while remaining strictly within the diploid realm.

The foliage, as I have noted in a post last year, is fragrant: somewhat like Raspberry and Pine combined. The plant has been immune to mildew and I would expect it to be similarly resistant to blackspot. (I won't know till later this year) The blooms, while unremarkable, are already being borne in large clusters on this 2 foot tall arching plant. Some panicles have over a dozen buds. Not surprising, given the parentage, the color is a soft "apple blossom pink" hue, and there is a modest scent.

For me, this is far from being a "finished" rose, but represents an avenue to make new hybrids that might escape many of the pitfalls all too easily inheritable from the standard Hybrid Tea/Floribunda class that currently dominate the marketplace. I think that the new garden shrub roses are going to have to be nearly indestructible compared to their predecessors; easy shrubs that provide four season interest. (interesting canes and architecture in winter, lots of bloom in the spring/summer, and colorful fall foliage, perhaps with bright hips as well) This seedling has already shown itself capable of providing colorful fall foliage, as have many of my R. foliolosa hybrids. Perhaps integration with Rugosa hybrids like 'Will Alderman' or 'Therese Bugnet' and repeat bloom will be reintroduced as well. I will also make crosses with David Zlesak's lovely red diploid 'Candy Oh Vivid Red', which has shown itself capable of breeding good rich reds when crossed with other diploids. (David's rose is also remarkably winter hardy and disease free in most climates. Well done David!)

Once there are more blooms of 87-09-01 open I might offer pollen to my colleagues, if interested. R. soulieana imparts great health, vigor and beauty to its offspring and this could be of value to other hybridizers.

Seedling 87-09-02, while seemingly as healthy and vigorous as 01 last year, has not been as nonchalant about our long, cold spring; its foliage has been "troubled" and the first round yellowed and dropped off. A sign of something I don't want to bring into a breeding line? Perhaps. I will watch it as the season develops. Many roses I grow here struggle to produce normal foliage until the weather settles into a warming trend.

Wednesday, June 1, 2011

106-09-01, looking for a way to breed useful Rugosas.

Once in a while you happen upon a seedling that is willing to do some neat tricks for you. Serendipity plays a huge role in choosing which seedlings I save for evaluation. I don't dare think about all the thousands of seedlings I have discarded that may have harbored secret capabilities. Alas, we work with the ones we feel have potential and let the proverbial chips fall where they may.

I've often pondered Ralph Moore's work with the Rugosas. 'Rugosa Magnifica' (van Fleet) was once Ralph used often, as well as 'Belle Poitvine' and various selections of R. rugosa rubra. I am aware that Ralph often disregarded ploidy when choosing what crosses to make and I have come to feel that there are definitely occasions when matching ploidy is potentially beneficial. For instance, this year I am flowering out a group of diploid hybrids made with 'Therese Bugnet', most of which involve R. foliolosa or one of its hybrids. These were created with attention to matching diploid-to-diploid. More on these in a coming update.

One of the lucky choices I made was in selecting a self-pollinated seedling from 0-47-19 (Moore, 1947: R. wichurana X 'Floradora'), code number 42-03-02. I am presuming (and undoubtedly correctly so) that it is a diploid, like its parent. So, making the same assumption about 'Rugosa Magnifica', I put the latter's pollen on 42-03-02 in 2009. I got only two seedlings, both growing like dwarf Rugosas, with Rugosa character in every way. Neither flowered in 2010, both are in bloom right now. The second seedling, 106-09-02, isn't quite "right"; the blooms are like miniatures of the Rugosa pollen parent, but very muddled in form, not opening correctly at times. The one I do like is 106-09-01 pictured here. The photo barely conveys its luminous purple-magenta coloring and the shimmery texture of the petals. The blooms are not large; about 1.5 to 2.0" across. Every one has been a simple five-petaled bloom and there is plenty of pollen available. (Needless to say I am using the pollen on a wide variety of other diploids and more)

I hope this little shrub (it is still only 15" by 15") will grow up to be something pretty, because I think a 3 by 3 foot mature specimen loaded with flushes of these richly colored blooms would be remarkable. With its parentage, I would expect superior disease resistance as well. We'll see!

Tuesday, May 31, 2011

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.

Friday, May 20, 2011

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.

Wednesday, May 18, 2011

220-09-02

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

Tuesday, May 17, 2011

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.