I’ll concentrate on I89-2 this season Jim. I don’t have the patience or space to deal with many once bloomers.
Hi Robert!
At least you got a few hips, good luck with the next candidates!
Jim, I have got an idea and a serious question, concerning these problems with “waiting for one after another to flower” … .
Have you seen any hints of linkeage or coupling groups of characteristics together with the existancy or non-existancy of a blotch?
I don’t mean the perhaps quantitative coded characteristics like the strength or clearness of shapes of the blotch, no, - but only the question if there is one or none - as in the case for Roberts rose above!
For example, the double flowers are linked to a resistancy against mildew on chromosome 3 of the rose genome.
If we knew a linkeage group for the simple question of the existancy of a blotch, we could estimate very early in development, if there is any chance to get a blotch and wouldn’t have to wait for flowers in every case (and I leave out crossing overs, as they are too rare to focus on them, as a hobby breeder).
Here are the very few examples that I know:
A gene or set of genes for “Pink flower colour”, e.g. is on chromosome 2.
“Prickles on the leaf petioles” seems to be on chromosome 7 if I understood it right.
(While the fact how many prickles is coded quantitative.)
And characteristic of “Double flowers”, as mentioned above, is linked to a dominant resistancy against mildew on chromosome 3.
So: if we at least had a few hints what we should look for, we perhaps could go on faster with the seedling selections.
Here are some characteristics, that are mentioned in T. Debeners “Encyclopedia of Rose Sciences” from 2003, and which are each added by a info about their genetical type (dominant, recessive, etc.).
Not for everyone, it is known on which chromosome they are located, as it seems, but for some (I already wrote them down above).
-
recurrent flowering________monogenetic recessive
-
yellow flower colour_______monogenetic dominant
-
pink flower colour_________monogenetic codominant
-
double flowers_____________monogenetic dominant
-
prickles on stems__________monogenetic dominant
-
prickles on petioles_______monogenetic recessive
-
dwarf phenotype____________monogenetic dominant
-
moss phenotype_____________monogenetic dominant
-
resistance to black-spot____monogenetic dominant
-
resistance to mildew_______monogenetic dominant
Perhaps we can add more and - what would be best, perhaps we can add such characteristics, that are linked to the blotch/non-blotch question.
Greetings from Germany,
Arno
Hi Timo, yes I got your mail from a few days ago and answered (a bit late) also via Forum, did you get mine?
Ciao! Arno
Hi Arno, yes I received it!
Hulthemia seems to be a hard little creature. 
I’ll waith and hope for the best. Fingers crossed for many flowers! 
Aufwiedersehen!
Question for Jim Sproul, what would you estimate the percentage of remontant seedlings when using Persian Sunset as pollen parent with a modern remontant seed parent?
Thanks, Robert
Hi Arno,
Initially, I thought that needle-like prickles, lax long canes, and mildew proneness was linked to the blotch gene, but now I don’t think that is true. Mr. Ralph Moore had told me that in selecting hulthemia hybrids that you should keep the mildew prone ones because they were more likely to show the blotch. That may still be true. For the non-remontant seedlings, I don’t think that there is a “shortcut”. You cannot tell which ones will exhibit the blotch. Working directly with ‘Tigris’, I had a higher percentage of nonremontant seedlings showing the blotch than seen when working with ‘Persian Sunset’. Most of the nonremontant seedlings have wild unmanageable growth similar to ‘Tigris’. They tend to become large plants with messy, undesirable rambling growth. And many of these, despite “looking” like a hulthemia, will not have the blotch.
I think that the real trick in working with remontant seedlings is in catching evidence of the blotch in young seedlings. Immature seedlings show very little of their full potential of the blotch. In fact in some seedlings, if they bloom for the first time during very warm conditions, the blotch will disappear (not be evident at all). Of course you want to get better blotches than that, but remontancy is the first step.
Hi Robert,
I think that remontancy is seen in about 25%, though among those seedlings that are remontant, the blotch was evident in the crosses that I made in less than 10% (but that may have been because I didn’t notice very light blotches in the immature seedlings and these were eliminated after the first bloom). I89-2 was by far the best blotched remontant seedling that we got out of ‘Persian Sunset’.
I wish I had kept exact records for percentages, but I did not. Even so, I think that the blotch gene may be present in remontant seedlings that do not exhibit the blotch because as I have mentioned in other posts, the white eye seen in modern roses seems dominant to the otherwise dominant behaving blotch gene.
Jim Sproul
Thanks Jim, as the total number of seedlings I produced from effort I did last season is small I will likely keep most in hope I can use them in line breeding, especially anything remontant.
Jim, in a 2007 RHA article you say Euphrates is infertile but in an other thread you write that their will maybe a very tiny chance that Euphrates can do some good with hybridizing.
I’m on a point to buy a Euphrates because your words motivated me to try but what do you really think? Should I buy or should I stay?
Hummm…
I have a seedling of Heidi X Persian Sunset that’s VERY prone to powdery mildew. So, perhaps it’s good that it has the mildew (at least, for now.)
It hasn’t grown much.
Robert, I think that you are right to keep all of your remontant seedlings from ‘Persian Sunset’. Good luck with them!
Timo, you are right that I made both statements about ‘Euphrates’ which seem to contradict each other. ‘Euphrates’ is reported to be sterile by others who have tried using it. There was also one report that someone did get a line of hulthemias from ‘Euphrates’. If I were you, I would not buy ‘Euphrates’ to use it in breeding. Instead, I would use other material that is available. You still might decide to buy it for its novelty. It is quite pretty, but has a rather short blooming period.
Enrique, you may have something there - best wishes!
Jim Sproul
Thanks for clarifing Jim! I’ll search for other material.
Their will be one day.
Jim,
What is your strategy with respect to germinating your Hulthemia seeds? A few years ago I purchased small plants of Roses are Red and Persian Autumn (the year they were introduced). This was really an impulse buy–the Hulthemia blotch has always fascinated me, but I live in Zone 3. I actually had to assure the sales person at Sequoia Nursery that the plants would be grown in the greenhouse–she didn’t want to send them to me. I am not sure that I can reconcile the need for hardiness with the need to keep adding enough doses of Hulthemia genes to preserve the blotch, but I thought I’d give it a try. I’m not even sure what the northern-most boundary is for the Hulthemias. Anyway, I did get a few crosses to take last season using the above mentioned roses as pollen parents–I have maybe 2 dozen seeds. The seeds have been in the refrigerator for 5 months–they have been removed from the refrigerator several times for 8-16 hours. So far, only two seeds have germinated. Do you (or anyone pursuing this avenue of hybridizing) have any special recommendations for germination, or are these just seeds that require an extended stratification? Thanks for any advice.
Julie
Hi Julie,
For the most part, hulthemia seeds germinate according to the female parent used. If you are using a good seed parent that germinates well, the hulthemia crosses should also germinate well. I haven’t tried the two that you mention in crosses (though I do have ‘Roses Are Red’), but had no problems germinating seeds from ‘Tigris’ or ‘Persian Sunset’. One of my own hulthemia seedlings that sets hips like crazy when used as a seed parent has extremely poor germination. However, using it as a pollen parent it germinates according to the tendancy of whatever seed parent is used.
I hope this helps.
Jim Sproul