The ploidy of Rosa acicularis on the Northern Great Plains

In the fall of 2007, I sent David Zlesak a plant of Rosa acicularis collected in Manitoba and also the ‘Kinistino’ cultivar that the late Robert Erskine of Rocky Mountain House, Alberta developed. David recently did a chromosome count of them and determinted the former was a tetraploid and the latter an octoploid. This shakes up my thinking of using Rosa acicularis in breeding programs. I was expecting this species native to these areas to be a hexaploid.

For developing a Rosa rugosa x Rosa acicularis hybrid that is tetraploid, I now have to revise my strategy. I either have to locate a Rosa acicularis hexaploid or cross the Manitoba selection with 'Kinistino’to obtain a hexaploid. I’m inclined to do the latter, since I should be able to obtain a selection with superior quality foliage and flowers.

I would like to get a better idea of the ploidy of Rosa acicularis on the Northern Great Plains, so it’s my intention to send plants to David from populations throughout this geographical region for chromosome counting. I want to confirm that a hexaploid of this species exists in this region. It might also be possible to determine the factors why the ploidy of this species changes. Example, perhaps it changes when it grows in different ecosystems. I think its interesting that the octoploid (‘Kinistino’) comes from a forested area just west of the Rocky Mountains, a totally different ecosystem from the Plains one that the Manitoba selection came from. On the other hand, maybe it came about because it was a controlled cross of two selections.

Hello Paul,

This is a fascinating topic.

I would highly recommend doing your hexaploid reconstruction by crossing the Manitoba selection with ‘Kinistino’. I’ll bet you’ll get the superior selections that you imagine.

But definitely don’t underestimate the value of the Manitoba selection for use directly with other tetraploids (species and moderns). It may be the fastest way to get where you want to go.

Also you might consider using ‘Kinistino’ directly with other tetraploid (species and moderns) to construct varied hexaploids to then use as you would have used a hexaploid acicularis.

And an idea “out of left field”… how about using a Caninae seed parent (canina, eglanteria, or glauca)with ‘Kinistino’ or the Manitoba selection? What kinds of gametes would come from this type of hybrid? The Caninae type of meiosis is supposed to breakdown in hybrids. [Examples: I think ‘Carmenetta’ is supposed to give 2N gametes in addition to other counts, and Albas are supposed to give 2n gametes] And look at the success Griffith Buck had with ‘Josef Rothmund’ X laxa.

Good luck with whatever you try. I look forward to hearing about your results.

Tom

This is a picture of an (acicularis X R15) seedling taken 2 springs ago.

http://picasaweb.google.com/HAKuska/RosePictures/photo#5091602158299699922

Last spring we had a very late freeze and a number of my early bloomers did not bloom at all (including this one).

I checked it yesterday and the new growth buds are just forming.


This plant did bloom last spring:

http://picasaweb.google.com/HAKuska/HenrySRoses/photo#5071154485145851058


I also have around 3 or 4 “sisters” of these 2 that have not ever flowered.

This year I will be able to look at the pollen with the microscope and dye so we should have a better idea as to what we are dealing with fertility and ploidy wise.

The pollinating of their blooms and the use of their pollen that I had done in the previous 2 years have not resulted in any seedlings. The reason may have been the rainy / cool weather that often occurs at that time of the spring.

If I get a good number of flowers this year, I will include a bag of (acicularie X R15) pollen along with the bag of (Rugelda X R15) pollen that people have requested.

Is acicularis x R15 synonymous with Henry’s Blend?

Henry’s Blend is a sister of my seedlings. After I obtained about 17 germinations from that lot, I distributed the rest of the seed to others.

http://www.rosehybridizers.org/forum/message.php?topid=3294#3294

Link: www.rosehybridizers.org/forum/message.php?topid=3294#3294