I have a large open pollinated seedling of R. setigera. It has never set open pollinated hips so I assume that it is the male version (R. setigera is thought to exist as either a female or male, not both).
It has just started its yearly flowering so I took a pollen sample for pollen diameter measuring. The results are: The average pollen diameter is 36.3 microns with a standard deviation of 1.4 (please note that my pollen are measured in solution).
For comparison, the following (please note, the following measurements may have been made on dry pollen) is a quote from:
Author: WALTER H. LEWIS
Published in: THE SOUTHWESTERN NATURALIST volumn 3: pages 154-174 (1958). (PRINTED 1959)
In particular Dave stated: “The amount of DNA in a cell (as estimated by flow cytometry) can be variable at a given ploidy level and overlap.”
In Walter H. Lewis’s paper that I cited in the previous post, he also looked at the size of the chromosomes. He stated (page 167): “Of further interest is the larger size of the R. setigera chromosomes as compared with those of all other species studied. The longest chromosomes of this taxon are approximately 5 microns in length while the longest of the other species rarely exceed 3 microns. This increase in chromatin is probably associated with the greater cell size (see Micromorphology) encountered for this species as compared with other diploid taxa of the section Cinnamomeae.”
H. Kuska comment: thus, it is probably safe to say that R. setigera is a diploid with an unusually large cell size.
I grow several open pollinated seedlings of Therese Bauer (Therese Bauer is reported to be ((Hansa X R. setigera) X R. setigera). It would be interesting to see what their pollen sizes are. Unfortunately, they are probably through flowering for this year in my garden (northern Ohio). If anyone has Therese Bauer and lives in a climate where it is still in bloom, I would appreciate receiving some of its pollen.
One of my Therese Bauer open pollinated seedlings is now having a bloom cycle. I used some pollen for diameter measurements. The pollen diameter was normal for a diploid, 30.5 micros. The standard deviation was 2.0 microns.
Since my male R. setigera was still in bloom, I used its pollen on several of these Therese Bauer OP flowers. If the crosses are successful, I should get some seedlings with 1/8 Hansa genes and 7/8 R. setigera genes. It will be interesting to see if the “different male - different female” plant character of R. setigera returns.
I read that R. setigera was origins may come from a rose crossed with something like a blackberry. Does anyone have an oppion on this? Has anyone done any DNA test to see where it actually lies in relationship to roses and near rose relatives?
I think it may Adam. R. setigera blooms later than most roses, similar in time to some Rubus, is the only dioeceous rose speces, similar to some Rubus species, and looks like Rubus in some ways as well with the foliage and growth habit.
I do not believe that anyone has looked at the relationship between Rubus and R. setigera yet. I have populations of R. setigera that are sexed and want to pursue getting money for that more and hopefully can be a part of a project looking at just that.
I followed the male sterility gene from female R. setigera through multiple generations. Using R. setigera pollen on non-setigera females has not been successful for me yet with any female germplasm. Perhaps there is some unilateral interspecific incompatibility. There are some more things that can be followed with the genetic control of sterility.
I have a 4x female R. setigera I induced with trifluralin. I have some seedlings of it now with 4x modern shrubs I’m excited to see develop.
Roy Shepherd in “History of the Rose” page 43 states:
“The name Bramble-leaved Rose properly belongs to variety tomentosa as the leaves of this variety resemble those of the wild blackberrys, various species of Rubus. The name R. rubifolia, published by Robert Brown in 1811, implies this similarity in foliage.”
For the tomentosa form of setigera see:
(I suggest that one look at tomentosa’s descendents as listed at helpmefind.)
I do not believe that anyone has looked at the relationship between Rubus and R. setigera yet.
This could be done easily enough, and relatively cheaply too. You could generate AFLP fragments by following the protocol of Koopman et al (discussed elsewhere on this mb) then run the data alongside a subset of thier data, which is publicly available. They used Rubus as a control.
I have populations of R. setigera that are sexed and want to pursue getting money for that more and hopefully can be a part of a project looking at just that.
I have populations of R. setigera that are sexed and want to pursue getting money for that more and hopefully can be a part of a project looking at just that.
How does one make money sexing roses?
I believe that David is talking about getting some grant money to cover expenses in a project.
On page 373, the following is stated about R. setigera:
“Although poor clade support makes it difficult to draw strong conclusions, some interesting biogeographic patterns are apparent in our analyses. The presence of rose species in North America appears to be the consequence of multiple introductions in a genus that mostly is concentrated in the Old World (Europe and Asia). If we consider R. minutifolia as sister to all other Rosa species, then there would be a split at the base of the phylogeny between North American and Old World taxa. Based on these data it is therefore not possible to determine whether the genus Rosa has an Old or New World origin. An obvious introduction of Rosa in North America occurred in Clade II with R. setigera, the only species of this clade that is native to North America.”