I’ve been wondering this for some time, but Enrique’s recent post finally pushed me to ask.
Could there be some benefit to also growing OP seeds as part of a breeding program? I’m showing my ignorance here-- for all I know that’s standard, although I’ve not heard or read anything about it.
I ask because it seems to me that hips set through OP are more likely to yield viable seedlings than those set through determined crosses. I understand the value of planned crosses and trying to select for traits to pass on, and I’m all for it! But seedlings from OP could also show desirable traits worth passing on.
Has anyone done any study to compare rates of “acceptability” (for lack of a better word) between OP seedlings and seedlings from crosses? What about germination and survival rates between the two? Whenever I read about OP roses, it’s usually with some derogatory statement about how unlikely it is that the grower will end up with a desirable plant. Well, isn’t that also true with planned crosses?
Enrique noted that Bayse’s Blueberry “Does’t work for me as a hip parent… don’t know why because it sets tons of OP hips.” Just wonder if the roses are telling us something.
The only disadvantage to sowing OP seeds is that the hybridizer doesn’t choose the pollen parent. If you’re just looking for seedlings, many of which will be pretty, there is nothing wrong with OP seeds, many of which are probably self-pollinated. It’s a pretty good way to see what characteristics are most likely to emerge from the seed parent (which is also the pollen parent in most cases).
If you’re trying to increase the dominance of a trait that is already well expressed in the parent, that’s not a bad way to go. Or if you would just like to reshuffle the deck with what you see as a good hand, that is also an OK way to go. The lines of some breeders are so inbred that the breeders don’t worry much about keeping track of parents. The late Joe Winchel reportedly had reached something close to that point with his program, and most of his later roses had about the same combination of parents. (If this is not so, please correct me, but this is what I’ve heard.)
On the other hand, if you have a plan and are trying to combine characteristics from one rose with those from another in order to achieve a particular objective in breeding, simply “stirring the soup” probably won’t satisfy you.
Some years when I don’t get enough seeds from my pollinations I do sow OP seeds, and I’ve had some pretty nice seedlings from those seeds. But I do keep making crosses that I think will lead to increased cold hardiness and increased disease resistance in roses. Sure enough, lots of them are not so good, but if I didn’t try…I’d not feel that I was using my head.
“Could there be some benefit to also growing OP seeds as part of a breeding program?”
First thing OP means either selfpollinated or “bee” pollinated.
Packed with petals tetraploids generaly do selfpollinate when single flowered diploids often are insect crosspollinated.
I infer that you are concerned by the tetraploids.
“I ask because it seems to me that hips set through OP are more likely to yield viable seedlings than those set through determined crosses. Has anyone done any study to compare rates of “acceptability” (for lack of a better word) between OP seedlings and seedlings from crosses?”
Grow OP seeds is tempting and most beginning breeders do. Trained breeders do occasionaly looking for heritability of desired features and production of germinatable seeds. Both things being not this common with roses and certainly the key points for rose breeding.
You will soon know that it is a very rare occurence among published pedigrees. When harvesting OP hips is quite easy ad some do germinate readily.
Percent of seedlings at or above parents quality is remarquably low for tetraploid rose vars. You will soon know that this percent is consistently much lower for OP seedlings. Average crossed progeny quality is as a rule quite far below parental one.
Roses with large flowers perfume and varied colors are aimed at insect cross polination. That means a breeding system privilegiating outbreeding.
Rose breeding is aimed at novelty much more than improvement. Wit a low percentage of ‘interesting’ seedlings the quest for hidden recessives is rather hopeless.
However if you have a var with a unique feature and low fertility you can seek a more fertile OP ofspring. But once trained at it you will find that growing a (lot of) rose seedling is enough investment for you to crosspollinate the seeds for better results.
Thanks for the answers, guys. I knew asking this I’d be showing my “newbieness.” I’m happy at this point to grow OP seedlings, although that hasn’t stopped me from making a list of what I think would be interesting crosses from time to time. At this point, that isn’t going to happen for me-- I’m lucky if I can keep up halfway on the weeding without trying to do the precise pollinating, etc. Maybe some day I’ll be able to give it a try.
Peter, Super comments, but what from what I have I heard OP seeds typically provide plants that are generally weaker due to inbreeding. I know that the bees do their thing and that there may be some pollen from another plant, but… some may be viable, so what are the chances? Just playing the devils advocate. I do harvest and plant OP hips as well and have some favorable results - just keeping the discussion going.
Rose history tells us that selected pollination of roses to get new varieties did NOT really begin until well into the 19th century.Prior to that time, the nurserymen would just gather the hips from their roses and plant them and see what happened.
I would say I generally get a larger percentage of interesting and/or desireable seedlings from purposeful crosses, but I have certainly gotten some wonderful seedlings from open pollinated hips as well. One of the benefits of open pollinated hips is the quantity of seeds you can harvest making your chances good for getting someting nice.
Some varieties produce a greater variety of interesting and different seedlings, though. Sonia, for me, produces the most interesting variation in seedlings. On the otherhand, Fabulous! produces almost all clones of itself.
Open pollinated seeds are definitely worth growing. Ralph Moore tests prospective new parents by growing OP seeds from them because he feels that this way, they show the characteristics they are likely to pass on to seedlings, without “interference” from a different pollen donor. He still does this, and occasionally, he releases a seedling from such OP seedlings. (See: ‘Iced Tea’ from a couple years ago; an open pollinated seedling from ‘Sequoia Ruby’)
I too grow OP seeds every year for exactly the same reason; it shows me what the plant can potentially do. My ‘Oshun’ is from OP ‘Abraham Darby’ seed, so in that case, it was well worth the effort.
Ultimately, however, I feel that planned crosses are where the real magic happens 95% of the time. Big numbers are your friend as well.
On the issue of weakness because of inbreeding–
Most of our commercial HT varieties have been bred back so much to the same lines that I’m not sure much further weakening is likely. They have such a large genetic pool to draw from that despite repetition of one parent (such as Peace) in several generations they may not suffer noticeable loss of vigor. A good example of inbreeding that did not lead to loss of vigor is Sea Foam: 'Sea Foam' Rose
It’s also possible to cross two species and come up with a pretty weak result. Granted, that combination may in later generations yield noticeably vigorous varieties, but the initial result may be pretty weak. Is this from being inbred? Probably not.
Unless there is a particular weakness that is concentrated through inbreeding, I think we need not worry about loss of vigor through inbreeding. Look at native stands of species roses that inbreed all the time. Do they weaken noticeably? Sure, there is individual variation, but the characteristics are mostly the same–thus the definition of the species. Nature takes care of the real weaklings.
As for us, we discard the worst of the bunch, so with luck and a good eye we’ll not run into serious decline because of inbreeding.
Meiland often selved several seedlings before crossing each other.
Dr. Basye suggested in one of the older ARS Annuals to inbreed for health and desired traits before crossing each other. In this way, you will eliminate undesired traits before hand.
He suggested a stragedy like this with a possible kordesii X Basye’s Amphidiploid for several generations for 1.) health, and 2.) repeat blooming.
I really am enjoying this thread. I agree with Paul and others and raise op seedlings from especially some of my advanced selections. I do so to look at what they tend to pass along and also get an idea of their genotype for certain characteristics that are primarily controlled by single genes (repeat bloom and doubleness of flowers). I have the data on the number of seedlings raised from different controlled pollinations and op families and number of advanced selections saved. I can go back and compare the frequency of advanced selections from controlled pollinations versus op families. I have a strong intuition that the rate of saved seedlings is much higher in controlled pollinations.
I have cut back some on raising op seed lately due to time constraints (finishing grad school). Here are some things that have guided me this fall in saving op seeds:
-I like to raise op seed of of superior roses with limited fertility (especially triploid roses) to try to get offspring that may be more fertile and still possess the traits I want. In essence I want to generate bridging clones that will allow the transmission of favorable traits more easily. Examples are trying to get diploid and tetraploid seedlings from the disease resistant triploid roses like ‘Seafoam’ and ‘Sunrise Sunset’ which may be more fertile.
-I still like to raise op seed from especially very disease resistant advanced selections to try to get additional resistant clones with greater diversity in color and other traits. I have one breeding line that is especially holding up well to blackspot. There are about 6 seedlings tracing back to a common grandparent that I’ve collected all the op seedlings off of that I could. They have gotten some blackspot at the end of the season, but it progressed very slowly and hasn’t overtaken them.
-I also save op seed off of diploid polyanthas and select diploid rugosas because I am familiar with these clones and know they are highly self-incompatible and the seeds they have are mostly all outcrosses.
In addition, I also favor the idea of using inbreeding as a genetic seive. With op seeds, like it was mentioned, we don’t know what % is really selfed or not. Anyways, by saving the inbreds with relatively more vigor and then using them to outcross often many deleterious alleles could be removed from the breeding line and result in hybrid populations with greater vigor. Although we probably cannot inbreed to the extend of corn with roses and develop F1 seedling populations with great uniformity (would we really want to anyway??) we can still obtain some benefit from purposefully using inbreeding for parent building. THis was done with 6x mums by Peter Ascher at the U of MN and really improved the breeding program. His cooperator thought he was nuts and would sometimes plow under is “sickly” inbreds before special guests came to visit the fields, but in the end Peter proved the process worked. He even developed an F1 seed strain that was uniform for plant habit that almost won an AAS award. It wasn’t commercialized though. Anyway, he showed the process was successful.
I don’t really have anything new to add, but agree with most of the positive observations for growing OP seedings.
My main reasons for planting OP seeds are as follows:
To test germination of a potential seed parent.
To assess the range of characteristics a potential seed parent may pass on to it’s offspring.
To try to find a more fertile “clone” (not really a clone), of the desired parent with lower fertility.
To evaluate recessive traits that may be “hidden” in the parent plant.
To purposefully concentrate desirable recessive traits.
I have a new shrub seedling this year that seems to have combined my favorite traits of two roses: ‘Baby Love’ - cleanliness, and ‘Marmalaide Skies’ - floriferousness. The cross was (‘Marmalaide Skies’ X ‘Baby Love’) X [(‘Marmalaide Skies’ X ‘Baby Love’) X (‘Marmalaide Skies’ X ‘Baby Love’)]. It was highly inbred, but is very vigorous, blooms a ton and appears to be very disease resistant.