Sunday, March 25, 2012

Early Notes on Darlow's Enigma Seedlings

For the past 5 years I have been trying to come up with a repeat blooming multiflora type rose to use in breeding with my Hulthemias.  I decided to try this at the suggestion of Mr. Ralph Moore.  He thought that a rose with an abundance of lighter colored blooms, with a central darker Hulthemia blotch, would make for a nice landscape type shrub.  I had to agree with him, and took his suggestion as "an assignment".  Since I have a thornless multiflora derivative that I use for rootstock, I decided to start with that plant.  Well, after 5 years, I am not satisfied with my progress and have had only one weak repeat blooming seedling that mildews badly, and have still not got the blotch into it.

So, in comes 'Darlow's Enigma', a rose that to me has all of the characteristics that I had been looking for in a multiflora, except that it is already a repeat bloomer, AND it sets hips well.  And more importantly, I have learned this year that it germinates very well, producing seedlings with great vigor.  Additionally, it is cold tolerant, fragrant, very disease resistant and there are reports that it blooms well even in shadier conditions.  So you may ask, "are there any bad qualities?"  Thorns - nasty hooked thorns.

This is my first year to plant "OP" seeds of it.  From it, 25 hips yielded 133 seeds, with 37 germinations.  Overall germination rate was therefore 28% - a rate that I consider good for most roses.  There are a couple of caveats when using it:  it only produces about 5 seeds per hip (meaning that you have to do many crosses to produce an adequate number to seeds); and approximately half of the seedlings are non-remontant (meaning that they only bloom in the springtime and will not bloom in their first year as new seedlings). Another potential problem is lack of compatibility with the Hulthemias - that is something that I will be finding out this year.

Today I went through all of the 'Darlow's Enigma' seedlings to check the frequency of several characteristics.  The data can be seen in the table below.


The first 14 seedlings noted above appear to be non-remontant.  They had already produced many leaflets without any sign of producing any blooms.  They were generally overly vigorous similar to other species type seedlings that I have worked with and were over-growing and crowding out the seedlings that were producing flower buds.  The non-remontant seedlings were therefore culled (except for 2*, more on this later), so that the repeat blooming seedlings (seedlings 15-33) would have more room to grow.

Looking at the table there are several observations.

None of the non-remontant seedlings produced thorns before the 3rd leaf node, and those that produced thorns earlier seemed to have a greater overall density of thorns (thorns/node).  The tendency for early branching was not necessarily related to thorniness.  Thorns were either curved or straight (see below).  The curved ones are particularly a nuisance.


The seedlings producing flower buds appear to have a great tendency toward fewer or no thorns.  The flower buds are usually appearing in 2 groups on these young seedlings.  For example, seedling #16 had 3 buds that were further along in development, but it was also producing a secondary grouping of 6 more buds (noted as "3+6").

Only about 1/3 of the remontant seedlings have bloomed so far.  Of these about half are white and the other half are pink.  I sniffed each of the blossoms, but was only certain of fragrance in one of them.  Seen below are photos of the first blooms of 3 of the seedlings.




The fragrant seedling is shown below. Note also its apparent lack of thorns.


*There were at least 2 seedlings that did not have the characteristic foliage that was present in all of the other seedlings.  Both of these were non-remontant, and because they were different, they have not yet been culled.  If they get too vigorous, I will probably take cuttings of them and eliminate the originals so that they do not compete too much with the remontant group.  Below is a photo showing leaves of the glossy seedling on the right compared to the characteristic matt finish on the left.


As mentioned, all but 2 of the non-remontant seedlings were culled.  Additionally, all of the thornier remontant seedlings were culled.  In the end, 15 seedlings remain. Please note that this data is on very young seedlings. Many seedlings change significantly as they mature. It very well may turn out that all of the seedlings will gain thorns as they mature such that all of the "thornless" ones will be as thorny as 'Darlow's Enigma'. An update will follow later on.


** For those who are counting, there are only 33 seedlings described in the above table.  Two seedlings were not listed because the were too small and appeared as runts that will probably not survive due to some incompatibility.  Additionally, 2 other seedlings must have succumbed early on.

4 comments:

  1. The pure white color of the second bloom is striking. Love the form of the petals and the delicate looking stamens.

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  2. Thank you James. There are several of the 'Darlow's Enigma' seedlings that I am still saving. The last one in the photo above is still looking good with minimal powdery mildew in the greenhouse. It turns out that it is not thornless, however there is a sister seedling that is still thornless.

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  3. The funny-looking seedlings smack of Rosa multiflora

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  4. Hi Jakub, yes seedlings of 'Darlow's Enigma' look very much like a repeat blooming R. multiflora. That is why I was so interested in using it to combine with the Hulthemias. I really love the floriferousness that comes from this rose.

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