I know climbing is dominant over bush form, once-flowering over repeat, glossy leaves over dull. What other traits are well known to transmit by simple dominance/recessiveness? I’ve read conflicting reports about miniatures vs. large flowering.
Judith, in my experience, minis seem dominant to larger roses. Also, I think dull pink is a definite dominant to every other color!
Jim Sproul
Judith - one of the most dominant traits that we have found is that singles prevail! Agree with Jim in that when using a mini as either parent, the mini characteristic will be more prevalent.
So Rose x rose would give definetely rose but what about other colors ? Do we know which colors are dominant and which are recessive ?
What would give these types of crossings ?
White x white
Red x red
Orange x orange
Yellow x yellow
Purple x purple
Andre33, that is a great question! Unfortunately the expression of pigments in roses does not follow a simple Mendelean genetic distribution. To complicate things further, many garden roses are tetraploid, although you do see a lot more triploid landscape shrubs these days. To predict the outcome of the proposed crosses you list, I would also say “it depends.” Some colors can hide recessive genes from several generations back and others like yellows have complex regulator genes.
White x White = hmm probably mostly white, but it depends on what shade. Many so called whites actually have considerable amounts of pink or yellows at the center if you look closely. Also white can be dominant over yellow, so it’s possible to get yellows and light pinks too if the alleles from both parents stack in the cross.
Red x Red = You could get any color really since reds do a good job of hiding recessive genes. Also note that with reds there is a bluing or purpling gene that is dominant. This gene causes them to fade to an purplish maroon color when they age. Red roses such as Oh My! And In the Mood are lacking these negative genes.
Orange x Orange = in my experience yellows, oranges, dark pinks and reds!
Yellow x Yellow = whites and mostly light easy fade yellows. Keep in mind that dark in fading yellows like Shockwave are recessive to lighter colored yellows ironically. Yellow is complex.
Purple x Purple = purples, lavenders, whites, and plenty of pinks!
I’m sure I missed something but that’s my crash course, good luck!
-Andrew (Plant Breeder and Horticulure Student)
Thank you Andrew for your detailed answer.
So, it seems that dark colors (red, purple) are dominants and light colors (white, yellow) are recessives. It’s funny to see that it’s very similar with corn colors. In corn, white means “no color pigment”. Is it the same for roses ?
Are blended colors also related to transposons ?
Check out this prediction chart which was done some years ago by Steve McCulloch, one of our consultants - [url]Account Suspended
John Moe
Thank you John ! That’s very interesting ! So the pink trait is finally not that dominant ! But I guess these results depends on the cv used. I’m not sure any red x red would give 91% red. It must depend also on ploidy and heterosigoty or homozygothy of the parents
Would you have the same for shapes, hardiness, fragrance and disease resistance ?
Their is some whites in roses that are codeing for no color and not just white. I can not remember for the life of me who did the research but I remember certain hybrid teas in the study were not acting the way they should and it turns out there was an accessory gene codeing for no color at all. Most white roses are either codeing for white or a really bad yellow or such and not no coloring.
There are also separate genes for the outside and inside of the petals.
Hardiness tends to be a mixture of genes. Say you cross something hardy to zone 2 to something hardy to zone 4. Most of them should be hardy to zone 3 but you will get the whole range of hardiness.
“So the pink trait is finally not that dominant ! But I guess these results depends on the cv used. I’m not sure any red x red would give 91% red. It must depend also on ploidy and heterosigoty or homozygothy of the parents”–It was said Ralph Moore with certain parent plants he used all the time could predict coloring of his seedlings very well. He probably knew the genetics of these plants very well. Hell Little Darling he probably knew better than anybody else. I still find pink shows up over and over again no matter what. But the thing is with 4 genes (most rose besides species) and a number of assesory genes that go with them the possibilities make it hard to predict unless you have used the parents a bunch. The only time I can predict with any certainty is with parents I used a bunch. Like Rise N Shine produces a lot of pinks and whites that fade a lot but hardly any yellows especially not dark ones.
About simple and double flowers. All F1 crossing from simple flowers parents give 100% simple flowers but crossings of double flowers parents gives every types of flowers with more doubles than simples (Han et al, 2002).
I guess simple x double gives more simple.
About repeating : Non-repeating cultivars gives no flower the first yeat after germination (de Vries et Dubois - 1978)
[quote=“Andre33”]About simple and double flowers. All F1 crossing from simple flowers parents give 100% simple flowers but crossings of double flowers parents gives every types of flowers with more doubles than simples (Han et al, 2002).
I guess simple x double gives more simple.
About repeating : Non-repeating cultivars gives no flower the first yeat after germination (de Vries et Dubois - 1978)[/quote]
Andre,
Recurrence may not be quite that simple, although what you say is mostly true about those which do not bloom in the first year after germination. I have grown some seedlings which bloomed a few weeks after germination, but then were once-bloomers. And some which do not bloom until their second or third season may be recurrent thereafter, as discovered by Felicitas Svejda in her work with rugosas. I’ve had some which do not bloom until they were several years old–and then were non-recurrent. At least these didn’t create unreasonable expectations by blooming early.
Peter
Ok so let’s say that usually non-repeating cultivars gives no flower the first yeat after germination but there are some exceptions.
Puzzlement germinated December/January 2013 and began flowering in November 2013. Other than about a six week hiatus over “winter”, it hasn’t stopped throwing flowers here and there. The “Red Hugonis” flowered a few weeks after germinating and has flowered reliably since. None of its siblings have flowered yet.