I have raised seedlings in the past from once-blooming mosses. Those seedlings didn’t bloom until the second or third year, and it was immediately obvious when the buds formed whether or not the seedling was mossed. I currently have my first seedlings from miniature moss parents. The first seedling is forming a bud at about six weeks of age. It does not appear to be mossed, but at that size (and with my poor eyesight) it’s hard to tell. Is it normally immediately obvious if a miniature moss seedling is mossed, or is it necessary to allow the seedling to gain some size before you can tell for sure. The seedling in question is Sequoia Ruby X Scarlet Moss. I have very limited space for seedlings and normally cull fairly ruthlessly after first bloom. I’m looking for mossed seedlings from this cross and don’t want to discard any seedlings thinking they aren’t mossed in error.
Great question Mark. There is the possibility that if there are some prickles (moss) the concentration can increase. However, if there really isn’t any signs of moss I highly doubt if it will become mossy. DeVries and colleagues looked at the inheritance of moss from the old moss roses and published a paper on it in 1984 (Gartenbauwissenschaft 49(3):97-100). They looked at the inheritance of recurrent flowering as well in these populations. Moss fit a single dominant gene model. What I can recall from my experience with ‘Scarlet Moss’ it seemed like ~half of the seedlings with non-mossed parents were mossed. THis would lead us to suspect the genotype of ‘SM’ is Mmmm (assuming it is tetraploid). Half the time the sex cell will have Mm and contribute moss and the other half it will be mm and won’t. I believe there is one major gene controlling if there will be moss or not, but in the presence of the dominant allele allowing for moss then other more minor genes can contribute to the degree of mossing we observe.
Mark, I agree with David. If you don’t see any mossing even on young seedlings, you probably don’t have the moss trait in that seedling. ‘Scarlet Moss’ produces some good mossing on it’s progeny. As David suggests, I am sure that there are other minor genes that contribute to the mossing as well as the prickliness of the mossing.
All of the below seedlings have ‘Scarlet Moss’ as a parent. The mossing on the seedling to the left is very soft to the touch, while the mossing is more “prickly” from left to right (the pink bud to the far right is a non-mossed seedling from a different cross). Mr. Ralph Moore brought the moss characteristic into modern repeat blooming roses.
I made that exact same cross four years ago and grew about 200 seedlings from he cross. It should be obvious when the bud reaches the 1/4 inch stage whether or not it is mossed. I would say that you can expect about 10% of the seedlings to have some mossing, mostly slight to moderate. I recall that 2 seedlings out of the 200 actually had intense mossing, but were otherwise unremarkable.
One of the seedlings from that cross was released this year, see link below.
David, what did they say about the inheritance of recurrence? I ask because I have a fair number of first-generation hybrids of once-blooming mosses, and I am wondering what they might be good for.
A few came from crossing modern roses with ‘Nuits de Young,’ which I used for its color and hardiness. Most of them are from crossing modern roses with one of two pink mosses that look like centifolia types to my eye, but are pollen-fertile. I used them because they have nice, soft moss. A friend of mine collects unusual old roses, and I got them from him. The varieties are ‘Marie de Blois’ and ‘Gracilis.’ These are quite hardy. Marie is listed as recurrent, but it never has been for me. None of these moss seedlings have bloomed yet.
Hi Roger! They said that the moss roses they had were RRRr for repeat (one recessive allele for repeat) and the cvs were ‘Salet’, ‘Marie de Blois’, ‘William Lobb’, and ‘Herman Kegel’. That seemed strange to me that they were all the same. Salet repeats for me somewhat, but maybe there are other factors which allow for the rebloom making the system “leaky”. Anyway, in their advanced generations (F2; all crosses were hybrid teas x moss parent) the segregation ratios fit their expectations for a single gene governing repeat. So, having one r allele in the mix is nice to help us recover more repeaters.
Just a follow-up to my original post. I’ve kept two of the Sequoia Ruby x Scarlet Moss seedlings to this point. Both seedlings have now bloomed a number of times, and the blooms of the smaller are now in the 1/4" range mentioned by Paul. The first seedling to bloom, the subject of the first post, showed no hint of mossing at first bloom and that has not changed with subsequent blooms. The second seedling, however, has proved more interesting. While it did appear slightly “hairier” (for lack of a better word) than its sibling at first bloom, it didn’t appear to be mossed. It is now producing buds that are moderately mossed. Since it has much the better bloom of the two, I’m very pleased with this turn of events. I’m fairly certain that the changes I’ve observed have nothing to do with the bifocals I now wear (which I didn’t have in February).