Please explain Eglanteria (particularly) Ploidy to a newbie

Hello. There was an article I had linked that I can’t find now. I remember that the seed and pollen had different ploidy. Can anyone explain which gives what? Are any hybrids known to behave similarly?

A similar rundown on other complex species would be great, or can I find a reference that you know of?

The process is called Caninae Meiosis. All rose species in the caninae section do this. The pollen contains 1 set (7 chromosomes), the egg cells contain (the total number of chromosomes minus 7).

R. eglanteria, which is pentaploid, has a total of 5 sets or 35 chromasomes. The egg would have 4 sets or 28 chromosomes, while the pollen has 1 set or 7 chromasomes. R. rubrifolia is tetraploid, so its egg cells would have 21 chromosomes and the pollen 7. (Where oh where is spell check when you need it!)

I’ve read that the Caninae meiosis begins to break down in hybreds. However, I’ve also read that some of the early Albas had (or probably had) caninae-type meiosis with two sets in the pollen and (I think) total chromosomes minus 14 in the egg. I also think R. hibernica (sp?) might have this type of meiosis. I’ve also read that Carmenetta (R. rubrifolia x a rugosa), has 7 in the pollen and 3 in the egg.

There is a website with more info on this. Possibly CybeRose Gardens? I don’t have the link handy.

Joan may be the site you are looking for.


Thank you very much! Joan, your information is excellent. Mark, that is the article I was trying to find.

Thanks Again!

Chloe, you should try what I’m doing… just cross and hope.

I’ve gotten germinations of Green Mantle X Applejack around December. All the seedlings are covered in mildew-- but perhaps it will out grow it.

I’m intrested in fragrant foilage. With time, I hope to create a parent from the eglatines that is 1.) tetraploid, and 2.) disease resistant, 3.) fragrant and can easily transmit it to offspring.

I hope for a thornless eglatine one day…