Wednesday, June 24, 2009

R. fedtscenkoana


With the advances in genetic testing and DNA sequencing, it has become possible to perform tests on historic roses to determine the facts about their ancestry in ways we never could before. Case in point: the Damask roses. In 2000, an article was published in Gene magazine in which the researchers studied the genes of key Damask varieties to determine which species contributed to their creation.

From the article "Triparental origin of Damask roses" comes the following abstract:

"Damask roses are one group of old rose varieties and a key material in old European rose improvement in the 19th century. To clarify the origin of Damask roses, we selected four varieties as the oldest Damask varieties and examined the relationship between the Damask varieties and their putative ancestors at the molecular level. Randomly amplified polymorphic DNA analysis of the Damask varieties proved that they had an identical profile, indicating they were established from a common ancestor. They have never been allowed to reproduce sexually; their reproduction depends entirely on vegetative propagation. We identified three Rosa species, R. moschata, R. gallica and R. fedschenkoana, as parental species of the original hybridization that contributed to forming the four oldest Damask varieties by sequencing the internal transcribed spacer of ribosomal DNA. We also found that all the four oldest Damask varieties had chloroplasts derived only from R. moschata, as judged from psbA-trnH spacer sequences. This triparental origin of the four oldest Damask varieties can explain some morphological characteristics of the four oldest Damask varieties, like fruit shape, leaf color and the 'Moss' character."

Authors: Iwata, Kato, Ohno

Reference: Gene: 2000-Dec; vol 259 (issue 1-2) : pp 53-9

A few years ago Kim Rupert sent me cuttings of one of his R. fedtschenkoana hybrids, where 'Orangeade' was the seed parent. The plant illustrated above is that hybrid. This is, in a sense, a primitive Damask and may have value as a source of some of the same genes that make the ancient Damasks such valuable shrubs. I am currently using this Rupert hybrid in breeding and it appears to be fully fertile as a pollen parent, and although it has never set seeds for me, Kim tells me it does so in his desert climate. Since both seed and pollen parent are tetraploids, I am assuming this hybrid is as well and I will proceed on that assumption.

The Rupert hybrid is a tall arching shrub with bluish-green foliage and loads of small (1.25") white blooms, about 15 petals per bloom. It is a freely suckering plant and extremely healthy in my climate. The blooms don't always open properly, which I think is a response to our weather cycles in the early Summer. The blooms have a very odd Musky-soapy scent that many people would find unappealing.

I will soon post a photo of one of this year's seedlings derived from this R. fedtschenkoana hybrid.

7 comments:

  1. Very interesting... did they say which four varieties they chose as the oldest?

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  2. I was wondering this too...

    I have 'Leda' here that is pre 1827 (and I thought this was old) but I did a quick search of HMF and the earliest Damask listed was from 1551 and was 'Versicolor'. Then was 'Red Damask' in 1560. In 1612 came 'Kazanlik', followed by 'Quatre Saisons', in 1633. 'Quatre Saisons' and 'Red Damask' are both listed as being from the follwoing cross: Seed: Rosa moschata Herrm. × Rosa gallica L.
    Pollen: Rosa fedtschenkoana Regel (copied from HMF). The other two are listed as unknown. This one of yours may contain some of the things that make the Damasks excellent garden plants with the added benefit if a lurking remontancy gene too.

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  3. Simon, Fa,

    I don't recall which four Damasks they tested, but you can be pretty sure R. damascena bifera and 'Kazanlik' were two of 'em. It is possible that 'Duchess of Portland' was another one. I think the paper does list the cultivars they used, but I don't have a copy of the full document.

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  5. Paul, if R. Fedschenkoana the species is successfully crossed with tetraploid miniatures, I wonder if the F1 could be easier to work with (maybe smaller shrubs and maybe less invasive)?

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  6. George, that is a perfectly reasonable idea, but there is never any guarantee that the offspring will experience any size reduction. I remember one of my first crosses 13 years ago mating 'Tuscany Superb' with 'Black Jade', and most all of the seedlings exceeded the size of BOTH parents by at least 2X! The best plant I still have from this lot is 10 feet tall and at least 12 feet wide. And yet, in a cross putting 'Muriel' on 'Twilight Skies', I got mostly very dwarf shrubs and small, restrained cascading style shrubs.

    I think your idea is well worth doing. I am simply working with a fertile hybrid that was given to me, thus saving me time and energy. Once you have a fertile seedling, you can worry about managing shrub size in the subsequent generations. Getting a fertile (species) hybrid in the first generation can be a much bigger obstacle.

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