microscope-Culbert Grant pollen

In a previous thread (on Sat, Feb 17, 2007), I stated the following: “I have had trouble using Culbert Grant as a parent. I finally have a 2004 (George Vancouver X John Davis) X Culbert Grant plant that produced nice dark red double flowers last June. Unfortunately it did not repeat. It spent the rest of the summer growing into a relatively large plant (for a 2004 seedling).” http://www.rosehybridizers.org/forum/message.php?topid=10129#10209

I now have looked at Gulbert Grant’s pollen with a microscope. The low power (100X) picture is at:

http://picasaweb.google.com/HAKuska/MicroscopePictures02/photo#5208403402712499682 There are a number of dead pollen and also apparently 2 sizes of living pollen.

If you use the right arrow on the low power picture, you can see the next 5 pictures which are high power (500X) images of individual pollen grains. The larger pollens are in the normal tetraploid range; the smaller pollens are a little larger than I would of expected for diploid pollens; but I assume that they are diploid. Thus, it appears that Culbert Grant is a triploid which would explain why it does not readily set open pollinated hips.

See the following for parentage: 'Cuthbert Grant' rose references

In the 2 listed offspring, Culbert Grant was used as the pollen parent. See: 'Cuthbert Grant' rose lineage

Link: picasaweb.google.com/HAKuska/MicroscopePictures02/photo#5208403402712499682

Thank you for the information Henry. It is strange though that I had CG a few years ago and it readily set OP hips for me. I’ve just obtained it again this year to use as a parent as I remembered how well it did for me previously.


Sorry for the mispelling; it should be Cuthbert Grant.

Rob, interesting, what roses were near your plant and were they in bloom at the same time?

I had about 350 different varieties at the time and it’s been more than 6 years since then so I’m not remembering so well. Ones that I do remember being close by were Gipsy Boy, Golden Wings, Sombreuil, Stanwell Perpetual and Jens Munk.

Several 2007 Country Dancer X Cuthbert Grant seedlings seem to be once-bloomers, so far; hardy vigorous plants;

blooms cupped, light red-deep pink.

Some 2006 Carefree Sunshine X CG are remontant; blooms red single; pretty unremarkable.

This year, pollen from above being put on Bucks to try to get good red; good real red Bucks hard to find.