In general juvenile blooming is linked with reblooming phenotype in roses which derived from Chinas, but is it also present in remontant rugosas?
I raised about 100 rugosa seedlings this year, about one half are OP seedlings of pure R. rugosa and others are offspring of Hansa. Although their parents are remontant (even “almost wild” form of R. rugosa can rebloom stably), only two seedlings bloomed until now, one is OP seedling of R. rugosa and another is Hansa x a well-reblooming hybrid rugosa. Both of them bloomed about 6 months after germination, about 40-50 cm height. Is it common that reblooming rugosas possess a non-flowering juvenile period? And do they share the same rebloom mechanism with something like Old blush or HT, which determined by homozygous KSN*copia loci?
There was a paper that has a rugosa with the KSN*copia
but that doesn’t seem to be the norm, the other papers that had lists of KSN*copia/null the only rugosa’s with a copia were with hybrids with poly/modern/china as one parent
I think with rugosa it was RoKSNA181 (as as in fedt/moschata) that leads to the rebloom
I have already read this paper, and the pollen parent of this seeding is Purple Branch mentioned in this paper. I don’t know the genotype of this seeding, but it likely possess at least one KSN*copia. Another seeding with no hint of PB also present juvenile bloom. I plan to do PCR test to certify the genotype of their KSN loci.
About moschata, I raised about 12 moschata x Mutabilis. Two of them with juvenile bloom in small clusters when the stem reached about 30cm,and after that they bloom constantly. The flowers looks like ‘Yellow Mutabilis’ bred by Peter Beals. Two seedlings have only one to few flowers with almost no rebloom, and the rest have no flowers even they are quite large.
Congratulations! Is that flower fragrant?
Now I found several (but still a small portion of) R. rugosa OP seedlings have juvenile bloom. Perhaps I can’t use the word “juvenile” because they are about 5 months after sprouting, reaching about 30 cm height.
All flowers are small to medium, single, mauve or white. The plants are typical rugosa: Compound leaves with 7-9 shiny, wrinkled leaflets on caterpillar-liked stems.
However, no sibling seedling of that double one bloomed now, they have long, slender, glaucous stems, usually thorny at base but almost thornless at top. Leaflets matte and less wrinkled.
Fortunately the double seedling repeats well, with buds on all shoots, just like a modern rose seedling, but the flower is almost scentless.
