Chromosome studies?

I’m very new at this, but does any one know if there have been any studies done regarding gene dominance? In college about a 1000 years ago, researchers were looking at mostly animals and humans. I’m curious about the good ole rose. From what I’ve read, the gene for pink color seems to be the only major dominant gene, and that may even be in question. Is rose hybridizing is an educated lucky guess with most everything built upon a definant maybe?

Hi Jeff,

Much of the genetics in roses is guess work. Though pink does seem to be “dominant”, you can cross some pink roses with each other and get almost every color possible. And though the miniature “gene” is considered dominant, you can cross some minis together and get the full range of bloom and plant size. Modern roses especially represent such a mixed bag that it is hard to predict outcomes. What helps is planting self or open pollinated seeds of roses that you are interested in using to see the range of possibilities.

I actually prefer roses that tend to give a greater range of characteristics in their off-spring.

Jim Sproul


I read your page about painting a rose. I read it with care, re-read parts, had my little charts out comparing what you wrote and cracked up when I got to the last paragraph. PINK!?! After all that, PINK? But I’m still hoping for a bit of planned luck.

I found some answers to dominance on Paul Barden’s site in an article by Roy Sheppard.


Your two examples on crossing some pinks and obtaining whole color range or crossing some minis and obtaining some non minis is exactly what is expected if these two traits are dominant but parent plants are heterozygous for them. I wonder if by crossing non pinks one can produce plain pink color?

With respect,


I asked the same questiuon last year. See the link below:


Wasn’t there an article in one of the newsletters a few years ago about the known dominant and recessive allules in roses? This is what I remember; the allule for non-repeat is dominant over repeat, the allule for cold hardy is incomplete dominant(additive)over cold tender, the allule for thorns is dominant over thornlessness and the allule for double flowers is incomplete dominant(additive)over single flowers. I’m going from memory here, I would have to look at the article again to see if I got these right and what I’ve missed.


Here on page 3 you find an overview:

One of the sources is this:


Jeff, I wrote that article a bit “tongue in cheek” - but pink/white is definitely the more common coloration that you will see. Even so, if you cross two yellow roses together, pink will not be the most common coloration among the offspring. Depending on the parents, you will tend to see more white, cream, and light yellow than pink.

Ilya, you are absolutely right. Tetraploids especially have “hidden” recessive traits that provide plenty of surprises when crossing modern roses exhibiting “dominant” phenotypes. That is why I think that experience planting open pollinated seeds from various cultivars first will give you a better idea of what to expect in planned crosses.

From an academic point of view, I think that it is valuable to know something about dominant/recessive traits in roses, especially with regards to non-remontancy. However, I wouldn’t let knowing what you know hold you back from trying something that might seem unlikely. Outcomes of crosses are often unpredictable. That is part of the fun!

Jim Sproul