Your rootstock could be R. multiflora (pink, 5-petal blooms) or Dr. Huey (dark red semi-double blooms).
Both are once-bloomers, although the Dr sometimes repeat blooms in fall.
dave

'Manetii' and a form or hybrid of R. canina are also used.

If you can post a picture, I can help to identify it. Otherwise look at my pics of rootstocks to see if you find it.

Here is a link that might be useful: Rootstocks

Thanks everyone for your replies.

There was a bud on the rootstock rose but it dried up. I opened it after and the colour seems like white or perhaps pink. I don t see any more buds. I will post a pic of the foliage soon.

Thanks dmaivn for the photos of the rootstocks!
s

probably multiflora.