Grootendorst as a pollen parent

Searching the forum I found that several people have used or were planning on using one of the Grootendorsts as a pollen parent. I was wondering how how those pollinations turned out?

Did the crosses take? Did the seeds germinate? And if they did , how were the seedlings?

Thanks in advance,

Paul

Hi Paul,

I looked at their pollen under the microscope and most of it was aborted, but a small amount took up stain and looked plump and were the diameter expected for being 1x. Sometimes with nearly sterile parents among the relatively few stainable pollen grains there routinely are some 2n pollen grains. I did not detect pollen the diameter expected for 2n pollen among pollen from the Grootendorsts. I tried using some of them as pollen parents on straight rugosas. If I remember right, there were a few seeds and out of those that germinated they seemed pretty rugosa like. I forgot if they were weak or what happened that they didn’t make it to maturity and were saved.

In the mid 1990’s I crossed rugosas with polyanthas to try to recreate the cross. The goal was to obtain Grootendorst like seedlings with the hopes of finding something more fertile to serve as a better link in crosses with modern roses. Out of thousands of seeds most died very young from incongruity. ~100 or so survived out of >2,000 seedlings to be planted outside. Out of those only 5 bloomed well. One had serrated petal edges like the Grootendorsts in a blush pink, and the others were pretty standard singles with clusters of smaller than rugosa sized flowers. Those seemed nearly sterile as well. There was one possessing the narrowest petals and ugliest flowers which sets an occasional hip!!! I got a couple seedlings to germinate from it. One seedling in fact was very vigorous. Unfortunately it seemed to fall apart for some unknown reason to me and died. The other one was weak from the start and died. I have some op seeds from this ugly duckling again this winter. Hopefully it will be a link to a beautiful swan at some point in time.

Perhaps there are other routes that would be easier to bring rugosa blood into modern rose lines than the Grootendorsts, but it is possible to get some seedlings from the Grootendorsts using them as a male parent.

Sincerely,

David

Hi David,

Thanks for the information. So there was very little viable pollen. I guess that would mean that one would have to use much more pollen than usual to get a decent number of seeds to form. Could the reason that your seedlings looked Rugosa like is because the pollen that would most likely be compatible with the Rugosa seed parent is pollen that carried the most Rugosa genes? I wonder if one tried pollinating a Polyantha with Grootendorst pollen that the seedlings would look more Polyantha like for the same reason.

I haven

This line hurts like hell. Imagine normal rugosas with hooked throns that are more numerous. Also, they sport readily from one color to another.

I have crossed (Rosa woodsii X R. rugosa)X Polyantha and recieved 2 seedlings which were healthy but not reblooming

Another plant that has Groot. or possibly Pink Groot. as a male parent is Marie Bugnet. The pollen is fertile having used it last year. crossed onto a rugosa.

Jadae,

I

I have tried doubling its chromosomes to get a fertile tetraploid but so far no success. I still feel that it is worth trying.

http://home.neo.rr.com/kuska/chromosome.htm

Link: home.neo.rr.com/kuska/chromosome.htm

Instead of Grootendorst you could try Kordess Roselina that if given in HMF as The Fairy x seedling is probably from rugosa pollen. It is quite rugose foliaged and has rugosa spines. It is probably more fertile as there is more pollen and a few one seeded hips every year. A quite recurent nicer plant also.

From the few OP seeds i have a nice (less fertile) seedling with few rugosa features except a nice larger flower.

It has good qualities to it and it would be nice to be able to tap into them instead of trying to re-invent the wheel.

From what I’ve read, chromosome doubling with chemicals has been very hit or miss. I have a mixoploid Rugosa plant from David where only 2 of the cell layers are doubled. But when the doubling works one should be able to some exciting things.

Pierre,

That’s a good idea. I like the color, I’m surprised that it has single flowers, being a seedling of The Fairy. I do like the fact that it is quit recurrent. Hortico sells it, so I’ll have add it to my wish list.

Thanks,

Paul

I got singles OP seedlings from ‘The Fairy’. None were unique enough to carry forward. I was surprised too.

I just bought this rose for my hybridizing next year but now I read it’s not a good one…darn.

What about Grootendorst as s seed parent?

From what I hear, it doesn’t form hips.

I haven’t ever seen an op hip on any of the Grootendorsts, and I sure looked hoping to find some. Thanks for the tip on Roselina! I will try to get one.

From all the talk about how difficult Max Graf is as a parent, I have found it quite amenable. Each year on the five plants I have covering a small area of fence there are several hips resulting in ~30 or so seeds most years. I raise them for fun. I actually have two very nice tetraploids with probably nearby John Davis (flower and leaf features have similarities) as the pollen parent and another diploid that appears to be a cross of a nearby polyantha. The two tetraploids are amazingly fertile. I hope to use them more in breeding in the years ahead. I have a baggie full of op seed germinating from one of them.

That is interesting about Marie Bugnet having a Grootendorst as a male parent. There is one at the MN Landscape arb and some in landscape plantings around town. I really admire the nice compact growth habit of this rose, dark foliage, and relatively large bright white blooms. It might be fun to cross this rose with polyanthas and start some congruity backcrossing if it has enough fertility. Julie Overom wrote a really nice article on congruity backcrossing for the RHA newsletter years ago.

Sincerely,

David

About F.J. Grootendorst it is Paulii x Mme Norbert Levasseur in HMF when Rugosa Rubra x polyantha in MR 10…

If done on a large enough scale, congruity breeding may work fine to recover fertility.

An easier strategy is backcrossing to other fertile hybrid mothers of each initial parent.

I did it and got instantly full fertility…Fertility was also much higher than expected with mixed ploidies semi congruity sib crosses. Also quite amazing is diversity of generation 2 when more than two species/lines are involved.

I hadn

David,

I just wanted to add that it is really is pretty exciting news about your tetraploid Max Graf seedlings! The more I think about it the more I think about the possibilities. That must mean that Max Graf creates 2n eggs ocassionally. One could use just about any tetraploid pollen on it and create something entirely different than the Kordesii hybrids that are hardy and healthy.

Paul

Hi Paul,

I think you got a cutting of the diploid one. The tetraploids are more blackspot resistant. There is one, 3K20 that is particularly an easy parent. It has a slow growth rate, but is pretty nice, hardy, and fertile as both a male and female giving some repeat blooming offspring.

I love your idea Paul of crossing Max Graf with other types of modern rose pollen to get new lines. I sincerely believe R. x kordesii is not a self because the semidouble flowers of it would not be possible (barring a new mutation) without a male that has a dominant allele for the major gene governing if a rose will be double or not (of course in the presence of this allele the degree of doubleness is governed by minor genes). It might be really valuable to cross warm colored tetraploids onto it as well as modern roses resistant to cercospora leaf spot (wow, the Explorers sure get it here in established gardens where the disease pressure has built up). I haven’t seen c.l.s. on my Max Graf (but my garden does not have that much pressure for it yet) and wonder if the susceptibility is coming from the probable modern rose male of R. x kordesii.

In the past I smothered open Max Graf flowers with bulked tetraploid pollen and got more seedlings that year. If one would have more strategy than I did that would be great. Perhaps pollinating MG with the new pretty disease resistant yellow Bailey rose hybrids would be a good choice to bring in more color and hopefully retain some pretty good disease resistance in some hybrids.

Sincerely,

David

Hi David,

I agree with you about R.x kordesii not being a self. Your experience with the tetraploid seedlings of Max Graf proves how easily it would have been for the same thing to have happen at the Kordes facility.

That

Given the lack of fertility of ‘F.J. Grootendorst’ as a staminate (and pistillate) parent, and the fact that Bugnet wasn’t always accurate listing the parentages of the roses he developed, I wouldn’t accept the parentage given for ‘Marie Bugnet’ is accurate. Still, it has something different in the parentage from most Rugosas to make it staminate but not pistillate fertile as a parent.

Since Bugnet’s last few cultivars had mostly white flowers, including ‘Marie Bugnet’, I think it’s possible he used the same pistillate parent to develop them - possibly Rosa rugosa alba. For sure that is the case with ‘Louise Bugnet’ and ‘Rita Bugnet’, which have similar flower and shrub characteristics.

Robert Erskine’s ‘Leafland Perpetual’ (‘Will Alderman’ x ‘Marie Bugnet’) was a very dwarf shrub (45 cm. tall as I recall). I used to think that was because of the Polyantha in the pedigree, but I don’t say that now because my thinking has changed regarding the parentage of ‘Marie Bugnet’.

Erskine’s last cultivar was ‘Gleam’ (‘Will Alderman’ x ‘Marie Bugnet’). It has semi-double, white flowers with a slight pink centre. While I’ve only observed relatively small plants of this cultivar, it appears the shrub will size up fairly good but will have an open growing habit.

I think ‘Marie Bugnet’ has a lot of potential to develop unique Rugosas. I’ve tried it several times with ‘Hansa’, and although I’ve obtained seeds nothing has been developed to date. I’ll keep at it. And also with other Rugosa cultivars.