Spinosissimas: 2 items

  1. Some have speculated that ‘Suzanne’ is a diploid, but I can find no documentation of it that states this for certain. Does anyone know for a fact? I was assuming it was a tetraploid, since many of the Spinosissimas are, and R. laxa is listed as a tetraploid also. Why would ‘Suzanne’ not be a tetraploid also?

  2. I have a cross of ‘Condoleezza’ X ‘William III’ from 2008 that has resulted in many seedlings. (I mentioned this before in another subject) I have culled what appear to be selfs of ‘Condoleezza’ and potted on about 25 of the ones that are clearly Spinosissima hybrids. However, I still have a number of seedlings left that are obviously Spinosissimas and I do not need any more of 'em. I am willing to distribute these for the cost of mailing. Let me know if you are interested: trospero at gmail dot com

Paul B.

Paul,

The average size of Suzanne’s pollen corresponds to what is usually found with tetraploids, according to David Zlesak’s study.

Peter

Thank you Peter, thats as I suspected!

Paul

Hi Paul,

I also counted its chromosomes directly too and it is tetraploid.

David

Brilliant, thank you David. I will share that info with the people at HMF, if thats OK with you.

Paul

I was surprised to hear that Suzanne is a tetraploid as open pollinated seeds from the Suzanne at the http://www.oardc.ohio-state.edu/researchoperations/rosegarden/

behave like diploids (in my breeding). I went back to the garden and collected some pollen from their Suzanne. The average of the pollen diameters is 33.3 microns and the Standard Deviation is 2.1 microns (40 measurements - 4 per pollen grain - 10 pollen grains selected at random). These values suggest to me that this particular bush is indeed a diploid.