see link for basic discussion of ploidy

There is some indication that polyploidyness is associated with increased vigor, even invasiveness, but it may not be a consistent phenomenon.

Polyploidyness indicative of vigor? One article:

Polyploidy = vigor?

Here is a link that might be useful: Ploidy

The actual number of genes varies by organism. As the article states, humans have 2 sets of 23, for 46. Roses have X number of pairs or sets of 7. Diploid would be 14; triploid 21 and tetraploid 28 (4 X 7). It is currently theorized that diploid, the basic form of many species and close relatives, might present greater cold hardiness and disease resistance. Many in the RHA are working with diploids in hopes of keeping it simpler and achieving their goals easier, as well as faster.

You'll probably read that triploids are infertile. Don't believe it! A number of the prolific Ralph Moore breeders are triploid and regularly produce triploids. My rose, Lynnie, is triploid and she is as fertile as roses come! Kim

I will second that, Kim! I had some hips from Lynnie in 2010 and they were my MOST prolific germinators! I have dozens of seedlings from it. I;m planning on using some of them this spring in my breeding so we'll see how well it passes it on.