Wide crosses in the Rosaceae family with roses

General Discussion
1

I wonder if trying wide crosses of other tribes within the Rosaceae with roses would have a higher probability of success if the other tribes chosen were those with similar pollen such as the Dryadeae, Kerrieae, and Rubeae of subfamily Rosoideae.

Title: Studies on pollen morphology of Rosaceae

Authors: Hebda, Richard J.; Chinnappa, C. C.



Authors affiliation: Botany Earth History, Royal British Columbia Museum, Victoria, BC V8V 1X4, Canada.



Published in: Acta Botanica Gallica, volumn 141, pages 183-194,(1994).

Abstract: " Light and scanning electron microscope studies of pollen representing genera from all tribes of the Rosaceae reveal a variety of form and sculpturing. All genera examined produce radially symmetric isopolar monads. Most genera in subfamilies Maloideae, Prunoideae, and Spiraeoideae produce tricolporate striate grains with large perforations in valleys between ridges. These tectate perforate grains have a chambered pore covered by arching ektexinal pore flaps. The ridge-and-valley pattern can vary from 1-long ridges parallel to the colpus, to 2-medium to long ridges tooping near the poles, to 3-short weaving and crossing ridges. Striate perforate pollen occurs in tribes Dryadeae, Kerrieae, Roseae (operculate) and Rubeae of subfamily Rosoideae. in some Rubus species perforate and verrucate sculpturing occurs. Tribe Potentilleae (= Fragarieae) produces pollen with microperforations rather than typical perforations and most genera have an operculum. Coluria, Fallugia, Geum, Orthurus, and Waldsteinia of Dryadeae produce striate microperforate pollen, suggesting that they may belong in the Potantilleae. Filipendula (Ulmarieae) is prominently verrucate. Tuberculate perforate sculpturing occurs in Cercocarpus, Cowania, and Purshia suggesting a natural group distinct from the rest of the family. The diverse Poterieae (= Sanguisorbeae) has mainly tricolporate and some hexacolporate (Sanguisorba) grains all with an operculum. Some genera (Agrimonia group) have striate pollen, but most have microverrucae and perforations. Within the tribe, a distinctive group of mainly south hemispheric genera (Acaena, Cliffortia, Cowania, Hagenia, Leucosidea, Margyricarpus, Polylepis, Tetraglochin) has tricorporate perforate pollen, often with a short colpus, sculpturing of macroverrucae and rugulae covered by microverrucae. These pollen characteristics suggest a distinct evolutionary lineage."

Another possible route is to utilize members from the Sanguisorbeae and/or Potentilleae clades since their DNA is closest to Rosa.

The diagram below is from the following web site (the 2 roses studied are Rosa Persica and Rosa Majalis):

http://www.bergianska.se/forskning_rosoideae.html

The abstract of their 2003 paper (which contains the same diagram on page 205 of the published manuscript) is at:

Http://www.journals.uchicago.edu/IJPS/journal/issues/v164n2/164022/brief/164022.abstract.html

Link: www.bergianska.se/forskning_rosoideae.html

2

I’ve thought about this too. Fallugia has an n=14 chromosome count while cowania has n=9. Apparently there have been hybrids between the two in nature. I wonder if the n=14 in fallugia is from a chromosome doubling event at some point in the rosaceae family tree. I would then wonder if you were able to cross it with a diploid rose if it would make a sort of pseudotriploid progeny (supposing fertilization happened and a seedling germinated and grew).

I see a couple benefits to attempt hybridization with these.

One: they repeat bloom throughout the season.

Two: they are very drought tolerant and may pass that trait on.

Three: Cowania can nitrogen fix which would reduce the need for fertilizer.

Four: they may offer new aesthetic features in hybrids such as interesting leaves and possibly tassels on rose hips. Depending on how the reproductive bits would form.

Negatives:

Unknown effects on disease resistance, especially for very wet environments.

Wide cross may make sterile weak seedlings.

These aren’t very cold tolerant.

I personally would love to make some attempts (gotta get some plants first though). I may attempt some crosses on easy to pollinate parents. I figure using these as a pollen parent would be easiest. Perhaps a rugosa would take it?

1 Like