Thornless L83 OP seedlings. How is that possible?

General Discussion
1

A couple of my L83 OP seedlings are completely thornless. L83 derives from both R. rugosa and R. wichuriana and I was wondering how thornless seedlings could result from such thorny ancestors. Any quesses? I’m thinking these would be usefull to cross with Commander Gillette or those that have CG blood.

2

If there were any thornless roses nearby the bees could have given you a present.

Patrick

3

Thank you Patrick. If these seeds were actually L83 x L83 and not pollinated by insects would it be possible for thornless seedlings to come from that cross or is more likely that bees gave me a present? :slight_smile:

4

I’ve noted smooth seedlings sometimes show up in crosses between prickled parents. I think it’s part of the genetic variation possible in most crosses. That’s why believe it would be relatively easy to select for smoothness in subsequent generations of crosses between these types of seedlings.

5

Rob,

I’ve noticed that the upper half of several of my different F1 rugosa crosses is practically thornless. The lower half is still relatively thorny… so maybe whatever cue is turning off thorn production in the tops of my F1’s, is just precociously occurring in your L83 seedlings.

Also, I seem to remember some earlier discussion about L83 having more than just rugosa and wichuraiana in its family tree.

Tom

6

Thank you Robert and Tom. I am planning to select for smoothness in subsequent crosses as you mention Robert. I have a New Dawn x Commander Gillette seedling that is smooth and these two might be good to cross with that one.

Tom, do you remember in the discussion about L83 having more than rugosa and wichuraiana blood what else may have been included in its breeding?

Thanks again guys.

Rob

7

Rob,

Where did you get Commander Gillette?

Are you sure if that’s it, and not Basye’s Legacy?

I sent hips of Basye’s Legacy-- does it look anything like Commander Gillette?

8

Hello Enrique,

The New Dawn x Commander Gillette cross was one I made several years ago when I lived at a prior home. I had to leave that plant behind in the move but it was labled as CG when I bought it. I wish I could remember where I obtained it from. The seeds from this cross were among a number of crosses from 3-4 years ago that I brought with me through two moves that have since germinated. I have three seedlings from ND x CG cross. Two have ND type leaves with minimal thorns and the third has non ND type leaves and is smooth. The first two are struggling with some die back but the third is doing well so far. The third is the one I’d cross with my L83 smooth seedlings and some of the seedlings that come from the Basye’s Legacy seeds that you sent me. Depending on how this NDxCG seedling does over the winter I would have plant material available next season for anyone who is interested. Having R. wichuraiana and R. carolina blood should provide excellent disease resistance and hardiness.

9

Hey Rob,

You wrote:

“Tom, do you remember in the discussion about L83 having more than rugosa and wichuraiana blood what else may have been included in its breeding?”

I don’t remember any specific rose being mentioned… just that the double flowers of Rosa kordesii would suggest that it had a double-flowered pollen parent.

And from what I’ve gathered, Felicitas Svejda developed L83 from Rosa kordesii X G49 (which was her own open-pollinated tetraploid Max Graf seedling).

Considering that Rosa kordesii and G49, both derive from open pollinated hips (on ‘Max Graf’), L83 probably has two different “wildcard” grandparents.

Tom

10

I noticed one of my Carefree Delight seedlings to be thornless…so it does happen.

11

Commander Gillette (aka Basye’s Thornless) is available from Ashdown.

12

Thank you for the information Tom. It’s much appreciated. I think I’m fortunate that these thornless seedlings turned up and I’ll use them to hopefully move forward with smooth stems.

13

Now I’m confused. One of the thornless seedlings has 3 canes but a new cane is emerging that is very bristly. Is this a case of genes sorting themselves out?

14

I almost mentioned this earlier. It’s common for some seedling to be smooth while in their juvenile state. It’s also common for seedlings bred from Basye’s Legacy to develop prickles as they mature or to switch from smooth to prickled canes as they develop.

15

Thank you for the response Robert. It’s a little disappointing to learn that smoothness early on doesn’t necessarily mean that a plant will remain thornless as it matures.

16

Rob, this is why it’s such a challenge to breed truly smooth roses. It has been achieved but the propensity to develop prickles is always lurking just beneath the surface.

17

This has been a good lesson for me. One more question regarding smoothness. Is it possible that a rose can be smooth on some canes and thorny on other canes of the plant? It just seems odd to me that the first three canes were completely smooth and the fourth arrives fully armed. Thank you for the response Robert.

18

“Is it possible that a rose can be smooth on some canes and thorny on other canes of the plant?”

Absolutely

19

Rob,

I had that happen to three of my plants this year. I have the two thornless Polyantas “Marie Pavie” and “La Marne” also I have “Therese Bugnet”. All three had thornless stems until about mid summer when all three sent up shoots with thorns or prickels. The poly’s stems just have a few thorns but Therese Bugnet’s shoot is very prickly. I had noticed the very prickly stems on other Therese Bugnets before.

Seems to me I read that temperature and/or stress might have something to do with it. It could have been the heat of summer or that we had very little rain this summer that triggered the thorny/prickly growth.

Paul

20

Thanks guys! I appreciate the education.