Seed shared by David Z in Dec 2011 (thank you, sir) resulted in one keeper seedling of 3K20.
3K20 = Open pollinated Max Graf (and it is a tetraploid, WOW!!).
…anticipating this to be a selfing.
I repotted it and I can tell you it has a huge root ball compared to what you might have guessed looking at it here (it has been deliberately buried a bit in the repotting process in pure soil).
I have topped it up with very decomposed sheep manure. No other feeds will be given (I nearly killed it with liquid feeds even tho they were 10 times diluted of full strength…just goes to show…).
That’s cool! I’m confused though… is it an OP ‘Max Graf’ or an OP of a tetraploid ‘Max Graf’ seedling? Wondering how you know it is tetraploid seeing as ‘Max Graf’ is a diploid (despite its tendency to make tets)?
Yes, Max Graf’s neat ability to throw tetraploids is WOW factor to be sure.
I’d rather be relying on nature to be doing such chromosome doubling than harsh chemicals which would have me worry about my own chromosome count being doubled on my skin / fingers / other parts … LOL.
Cool… thanks… maybe just pollen to keep quarantine happy
The caffiene I tried in doubling laevigata is about to be tested. For some strange reason I’m having trouble striking the cuttings from teh treated plant. Not sure if this is a good sign or not??? Maybe this is a viable alternative to colchicine, triflurallin, and oryzalin???
Q1. Ohhh?? wazzup with quarantine these days your end??
Q2. Caffeine to double chromosomes sounds very user safe, good luck with it let us know what transpires… where will you get the root tip squashes done?
I’m doing the squashes myself but am a little unsure whether the squash is the right way to go about determing whether a change in ploidy has occured. It seems that the root material is not derived from the same tissue layer (L2) that results in the formation of sex cells. I can’t remember specifically but I think the root tissue dervied from L1 (it was either L1 or L3???). This might cause a problem because the people who did the doubled wheat with caffiene found there was everything from partial doubling to complete doubling so chimeras were common. I might do a root squash and find them still to be diploid but the pollen might be doubled… so I’m wondering whether I should wait until it flowers and look at the pollen diametre instead to look for a diametre indicating 2n pollen or n pollen… maybe I will do both… unsure yet.
Quarantine to down here is same-old-same-old. Ineffective. Clamping down (supposedly) to try and prevent myrtle rust getting in but things are still getting through under the rules they told me before. Pollen would be less of an issue for them (despite roses not being a known host for MR).
What you write about the optimal method of confirming the doubling of all three layers (L1 L2 and L3) as opposed to one or two layers (in a partially doubled rose / chimera-mosaic) is something I am totally interested to hear the answer to, myself !
Anyways, even if your (presumed diploid) Laevigata was doubled to tetraploid in all 3 layers (L1-L2-L3 = 4-4-4), I guess it is theoretically possible for it to still throw mixtures of 1n, 2n, 3n or even 4n gametes !!!
Such is life with roses.
Look at what Max Graf (diploid) has done in producing its 3K20 babe (a tetraploid)…
Thank goodness us humans don’t have such issues in reproduction !!
3K20 is a relatively large flowered double that is very fertile and relatively climbing. With double flowers it is a cross as more than 5 petals is dominant to five petals (like ‘Max Graf’). The neighbor I suspect is the paternal parent is the triploid ‘John Davis’, which does have R. x kordesii in its background. 3K20 is crazy fertile and I think readily self fertilizes, but also crosses easily when emasculated and pollinated. Part of the reason I got ‘Max Graf’ as well as ‘Robin Hood’ is that as diploids, they had reported 4x offspring (R. x kordesii, ‘Eva’, etc.), and I wanted to generate 4x offspring from them with hardier dads.
David, I have tried a cross which I hope will produce something like ‘Max Graf’ after our discussion a few years back about ‘Kordesii’. I crossed my seedling, “Rugosity” (OP Ann Endt) with R. wichurana and am hoping for something with a little more fertility than ‘Max Graf’. The cross produced only a small number of seeds and I’m not sure how good they are as they seemed poorly develolped and small. I think I will repeat the cross next season but the other way around and using a different rugosa like ‘Belle Poitevine’, ‘Freycinet’ , and ‘Anne Hall’.
