I’ve been pondering ways to ease diploid genetics into tetraploid roses, and was wondering whether anyone has succeeded in crossing diploids (or anything else, for that matter) with alba hexaploids like Great Maiden’s Blush. The fact that they have diploid gametophyte stages (2,6 rather than the more usual 3,6) makes me wonder whether I’d be better off spending my time trying to source some colchicine.
I have crossed the tetraploid ‘George Vancouver’ as a female with Rosa alba semiplena as a male. The hexaploid albas as you know have a modified section Caninae meiosis with 2x pollen and 4x eggs, so direction of cross would influence the ploidy of offspring. THe seedling I raised is 4x as expected.
Thank you, Dr. Zlesak, for that information. It’s as I suspected, though not as I wanted. I’m new to dealing with the genetics of life forms with diverse ploidies, and getting my head around all of the issues involved is a little challenging still.
I acquired some oryzalin, and will move on to Plan B.