OP L83 seedlings...what to expect?

I’ve got a number of OP seeds from L83 that have germinated. Can anyone share their experiences with L83 seedlings and what I might expect? I’ve already noticed that the leaves are pretty much the same between the seedlings but there is a wide difference in the amount of thorniness between them…from little to heavy thorniness. I’m interested in learning what I can expect regarding potential petal counts, remondancy traits and disease resistance. I’m assuming I’ll get mostly single pinks and maybe a white here and there. Thanks for any information!

Single is recessive to double flowers. Any seedlings that are semi-double to double should be crosses with double neighbors or semi-double neighbors. If you have the allele for the major gene that governs if a seedling is double or not, then you will probably have a wide variation in degree of doubleness with the potential for some very double offspring because it looks like L83 carries many minor gene alleles that contribute favorably to doubleness. This is seen in offspring of it like the very double ‘Louis Jolliet’. Other direct offspring are pretty double as well like ‘George Vancouver’ and ‘Marie Victorin’, although more typical for double roses.

‘William Booth’ also is single, but can produce some very nicely double offspring. I think there is more variability for traits in general out of ‘William Booth’ than L83.

I think you’ll get a lot of relatively slow growers like L83. I think it is a great rose- hardy and disease resistant, but relatively slow growing. However, since it is so hardy and healthy, L83 does get to size over time even in my zone 4 growing conditions. L83 is kind of hit and miss to root from cuttings, at least for me. Many of it’s offspring are better.

Sincerely,

David

I was going to ask about William Booth, but you already filled that in. I recall the words of a fellow Canadian who stated that L-83 is redundant if one has access to William Booth.

Now why is it that we must always confine breeding to crossing with doubles or semi-doubles? I adore HT’s & OGR’s, but there is equal appreciation for singles and semi-doubles. Some have luminous color and great fragrance. With doubles, one can’t see the teasing circle of stamens surrounding the pistils, which I consider to be an integral part of the show! Every rose has its merits, and singles or semi-doubles are of no exception. David Austin managed to turn people’s heads away from that high pointed peak back to the old fashioned cupped & quartered form in less than 30 years. Wouldn’t it be nice if heads were to turn a little further back to welcoming a rose that reveals some stamen!

David,

Thank you so much for the great information and for sharing your experiences. Is it safe to assume that I should get a good percentage of repeat bloomers from the batch? Can I also ask, based on your experience with L83 seedlings, will I see any blooms on very young plants like I do with modern hybrid crosses? Thank you again David.

Rob

Hi Rob,

That’s a great question about frequency of repeat blooming seedlings while they are still young. Many off of L83 or even William Booth do not flower until larger and more well established and some even behave more like one time bloomers even in crosses with repeat bloomers- kind of like William Baffin offspring, although WB produces more one time or stingy bloomers it seems.

I wonder why this happens. I wonder if it has something to do with rugosa being in the background of these Explorer roses through Max Graf. As far as I understand, R. rugosa is the only major species rose that actually is well adapted for repeat bloom. Natural populations do so and the hips mature quickly compensating for later summer flowers having less time to ripen their fruit. There are repeat flowering roses out of R. gigantea and R. chinensis and all that led to our modern roses, but they are selected and as far as I know not adapted and found reliably in the wild. Rosa laxa and R. arkansana and others have some repeat or fall bloom, but do not reliably ripen their later fruit.

R. rugosa I think is homozygous recessive for the major gene governing repeat bloom. In crosses with one time blooming species roses one primarily gets one time bloomers. In crosses of rugosas with modern repeaters, one gets enough strongly repeat blooming roses to suspect the same gene with recessive alleles governing repeat bloom is controlling repeat bloom in both rugosas and modern roses. However, I think there are many minor genes that govern the juvenility period of rugosas and when and to what degree repeat bloom is displayed. Rugosa seedlings often do not bloom the first season for me and later, once established, repeat bloom. I suspect this is a great adaptation to allow young seedlings to be competitive and carve out a niche for themselves in their new environment before they start investing in flowering. Modern repeat blooming roses don’t have all the years in the wild for natural selection for the more minor genes that hold back repeat bloom or modify its expression for survival advantages.

My suspicion is that perhaps the one time bloom allele from R. wichurana may have been selected out of the Explorer roses, but there are still minor genes governing expression of repeat bloom coming through by the rugosa heritage. Some seedlings of Explorer (R. kordesii types) with modern roses get combinations of these minor genes from both parents that contribute to stronger or less strong expression of repeat bloom. Perhaps also there are different mutations leading to the recessive allele for the major repeat bloom gene. If Andy Roberts is correct, the recessive allele of this major gene may be a knocked out giberellic acid gene. Depending on where changes in the sequence has occured, it may be totally unable to produce its end product (form(s) of gib acid), or do so in a much more limited manner. Perhaps recessive or compromized forms of this major gene differ across germplasm for how much less end product is synthesized. Perhaps roses that have stronger repeat bloom have less end product (appropriate versions of GA) than those that are more stingy in repeat bloom.

These are just some thoughts over seeing so many stingy repeat bloomers among many of my Explorer crosses including L83 and even William Booth. I’d love to learn the thoughts of others.

Sincerely,

David

How do you think a tetraploid-converted rugosa would behave as far as repeat blooming is concerned? It should have 4 recessive repeat alleles then, so a cross with a tetraploid once-bloomer could produce repeat bloomers straigh away?

What a great explanation David and very easy to understand. It’s amazing how much you know about genetics. Thinking back to my pure rugosa seedlings I remember that the vast majority did not bloom their first season. There were a couple that did bloom under lights not too long after germination but their numbers were very few. Your thoughts on R. rugosa being homozygous recessive for the major gene governing repeat bloom makes sense to me.

I won’t expect blooms on my L83 seedlings the first season or two and hope that when they do bloom they will be repeat bloomers. You mention that L83 offspring were slow growers for you. I’ve also noticed that for the majority of my seedlings so far, although I’m at an early stage with them. There are a couple that are growing like gang busters that I will keep a close watch on.

I’m keeping an eye on the degree of thorniness as well. It’s interesing how varied the difference is. I have some on one side of the spectrum with no thorns that I can detect so far to one on the other side that is as thorny as a pure rugosa might be. The thorniest of the bunch seems to be the most vigorous grower so far. Non of the leaves show any rugose texture so far.

Thanks again for such a great response to my question.

Based on the guidance of a friend, I’ve come to realize that Explorer seedlings may take at least two years to flower, so I’m not surpirsed by your explanation. I’m sad to hear that William Booth produces stingy offspring. I want to work with this rose, and still do. Can you say, David, with some accuracy, if WB will at least produce some roses that would (eventually) repeat twice in a season? Once at the start of the season, and a decent flush near the end. In other words, a twice-blooming rose. I ask this since my view of ‘stinginess’ may vary at times from the norm, depending on the rose.


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Here french Riviera with a long growing season even if large only a few rugosa do bloom the first year. Obviously the flowering of less than one year old seedlings is inhibited.

David, I do not think flowering is regulated by a gene for recurrence.

A rather recent and said to be universal for all plants stronger theory is that there is a blooming signal from the leaves and inhibitors from the growing point.

Flowering inhibition is a most important part of plant architecture. A little plant and a tree differ strongly in flowering inhibitions. These inhibitions are temporary and in due time are supressed by a specific signal like age or undergone amount of cold, day length or another condition particular to a given species flowering inhibitions.

Recurent flowering then is inaction/failure of the inhibitors our modern roses got from allmost all parent species. Gigantea, chinensis, moschata, gallica, multiflora, foetida, wichuraiana, all are once blooming. Rugosa that contributes little outside of Kordesii derivatives and fedtshenkoana are the only recurent species involved. I do not know enough about the later but we know that rugosa has juvenile phase flowering inhibition.

A failure of the inhibitors easily explained in interspecific crosses if inhibitors are different? Confused by different signal or different mechanism or needing a specific genetical environment that is two or more genes cooperation to be expressed.

Explanation of non recurent seedlings from recurent parents is easy then: it is rebuilding of inhibitor partly provided by both parents. As well the not so rare recurent seedling from cross with a non recurent species is failure of inhibition. And all other anomalities observed such as very early flowering once blooming species seedlings.

Hi Dee, Don’t be discouraged with William Booth. You should get some strongly repeating seedlings in the mix. I was at a friends house a couple nights ago that I gave some cuttings of some selections out of William Booth a number of years back. Some of these selections I didn’t save in my garden. There is a cross with Splish Splash that is a bright single red kind of like Nearly Wild in growth habit in that it is so compact and blooms so often. There was also a selection of WB x Hawkeye Belle that is a nice pillar rose and very double and a nice deep red/crimson. Like Pierre mentioned when and how often the growing point converts to reproductive structures can really influence plant architecture. There was a full sibling of this red Splish Splash x WB seedling that was truly once blooming at least here in MN.

Thanks for your thoughts Pierre on repeat bloom. It would be great if someone would follow up on and take the work on the subject done by Andy Roberts and colleagues further on inhibitors and signals for repeat bloom in roses.

Sincerely,

David

Dee,

I didn’t say L83 is redundant. I said 'William Booth is a good substitute if L83 isn’t available. Any rose with a relatively good track record like L83 for developing good quality and disease resistant roses can never be considered redundant.

I’ve decided to develop a L83 x ‘Assiniboine’ breeding line to hopefully improve the chances of having red colour in the progeny in a Rosa kordesii breeding program. Also, hopefully to develop more compact plants. In northern climates (Zone 3), we need more red cultivars cold hardy to this region.

LOL Paul, was that you? It’s amazing the sort of things that stand out in my mind, as much as I like teasing :wink:

r. kordesii, L-83 and William Booth are a colossal blur at 8am. Let me have a look at my notes…“Rose germplasm L-83 is similar to and has r. kordesii in the parentage but is cold hardier. Therefore, there is no point having r. kordesii if one can access L-83”.

Please tell how you make out with with Hansa x L-83, if you are still making that cross.

I like your idea of developing an L83 x ‘Assinboine’ breeding line Paul. How do you feel about L83 x ‘Cuthbert Grant’ for the same purposes? CG sets wonderful hips and has a great red color.

Rob,

Your idea of L83 x 'Cuthbert Grant may be better than using ‘Assiniboine’ to obtain progeny with red colour. After all it has ‘Crimson Glory’ in the parentage. Using ‘Assiniboine’, since it is 1/2 Rosa arkansana my idea is to retain the cold hardiness of L83. Then again there might not be that much difference using ‘Cuthbert Grant’. I say go for it.

I’m a huge fan of ‘Cuthbert Grant’ and have been toying the idea of using it with one of my L83 seedlings, if any show promise. I’ve also thought that ‘Cuthbert Grant’ would be a great one to use with R. glauca/its hybrids with the hopes of getting a dark red rose with the R. glauca colored leaves. All these plans in my head…now I just need to move to a place with more property.

Have you considered taking a look at Joyce Fleming’s PALS Niagara? L83 was the pollen parent, and according to the description on HMF the bloom is medium red. I just put it in this spring and it should bloom within the next week or so, depending on the weather. I’ll take a few pictures when it does and put them on HMF. Since Red Hot was the seed parent, it might make a better donor for repeat blooming.

Link: www.helpmefind.com/rose/pl.php?l=2.37473&n=45006&tab=1

There’s this one too. See notes.

Link: www.helpmefind.com/rose/l.php?l=2.37514.1&tab=1

Thank you Liz and Robert. Both of those selections encourage me to move forward with my L83 seedlings…if something promising comes forward. Hope to see pics of ‘PALS Niagra’ on HMF at some point. ‘Irma’ might be a good one to bring out some yellow with ‘Sunsprite’ as a parent. Thanks again.

…and thanks to David for the tips on William Booth :wink:

Hi

What does OP stand for - open pollination? Does this mean the plant has self pollinated or it has been insect pollinated? If OP means open pollination how valid is this to claim one is the breeder?