Canina Chromosome pairing

A meeting place for rose breeders.
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Re: Canina Chromosome pairing

Post: # 67828Post Plazbo
Fri May 11, 2018 8:35 pm

Plazbo wrote:
Wed May 09, 2018 6:44 pm
I am working with Lord Penzance, Lady Penzance will be coming in the next few months. Given a few comments on here i shouldn't expect germination until the second season so probably wont be til next year to see if any of the couple hundred Lord P seeds germinate

I couldn't see an edit button but just an update on this for anyone interested now or in the future, I was just out checking my various pots and seedlings. Lord Penzance does appear to have some capacity to germinate within a year. I don't cold stratify, I just put seeds in seedling trays early march (march was unusually warm, min temp didn't drop below 15c/59f like previous years, those min temps and below didn't start until April...the last 2 weeks the min temps have been between 10c-5c/50f-41f) and make sure they remain damp. Anyways around a dozen Lord Penzance seedlings (out of a couple hundred planted seed) have spouted cotyledons so only 2 months since sowing.

Karl K
Posts: 1051
Joined: Sat Jun 02, 2012 4:49 pm

Re: Canina Chromosome pairing

Post: # 67829Post Karl K
Fri May 11, 2018 10:09 pm

Warren wrote:
Fri May 11, 2018 7:18 pm
A very good question, in the last couple of years I have been using roses from Synstylae or its offspring. Even at the level of F3 you can still see some influence of Synstylae stigma's.
It's there if you look. In the modern studies of eastern North American roses, Rosa setigera seems to be largely disregarded. But Feast and Pierce had no trouble raising hybrids from the species. I don't know that they even bothered with hand pollination.

Hurst saw Synstyle influence in R. carolina L (1753) = R. humilis Marsh. AADD. I haven't seen the species, so I have no opinion. Furthermore, there seems to be more than a little confusion. One of the pictures on HMF is identified as R. carolina subsp. blanda and identified as a DD species. That must be R. blanda.

Other pics look more like R. palustris (I think). But I found another picture, reportedly R. carolina, with exserted styles. It looks too much like R. setigera. ... 02_ahp.tif

Larry Davis
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Location: Kansas

Re: Canina Chromosome pairing

Post: # 67837Post Larry Davis
Sun May 13, 2018 7:40 pm

Sorry for the long delay in replying to Warren's query re: do the chromosomes that don't participate in bivalent formation contribute to expressed characteristics of canina types. I think that Hilda Nybom's group, in particular, Werlemark, did the most detailed studies on this. There seems to be a strong tendency toward matriclinal inheritance of some traits because the chromosomes carrying them don't mix in any regular way with those that make regular pairs during meiosis. Also the chromosome balance obviously favors the mother's side of things, even if not all the genes on those chromosomes are fully expressed. Several years ago I wrote an article in the RHA newsletter about this, reviewing each chapter of Werlemark's thesis on the subject.

In some ways it's like crossing a pollen diploid with a tetraploid, or higher ploidy maternal parent. The diploid contributes fewer copies of everything. And in later generations that tendency is repeated.

Karl K
Posts: 1051
Joined: Sat Jun 02, 2012 4:49 pm

Re: Canina Chromosome pairing

Post: # 67886Post Karl K
Mon May 21, 2018 4:10 pm

I found a couple of papers that may be of interest.

Journal of the Arnold Arboretum 12(1): 3-22 (Jan 1931)
The Origin and Relationships of the Pomoideae
Karl Sax ... 4/mode/1up

This one gives further information about differential pairing of chromosomes in Rosa, Rubus, Fragaria, etc., as well as competing theories for the origin of the X=17 Pomoideae species.

Phytochemistry 12(5): 1095-1101 (May 1973)
Phenolic compounds of the subfamily pomoideae: A chemotaxonomic survey
James S. Challice
The subfamily Pomoideae has been surveyed for leaf phenolics and it has been shown that flavone glycosides are present in the genera Sorbus, Aronia, Chaenomeles and Hesperomeles in addition to the previously reported occurrences in Crataegus, Malus and Pyrus. The dihydrochalcone phloridzin, a typical constituent of Malus, has also been found in Docynia. Arbutin and phenolic acid-calleryanin esters are apparently restricted to Pyrus. Naringenin and eriodictyol glucosides have been detected in Pyracantha, Sorbus, Photinia, Chaenomeles and Hesperomeles. A number of Pomoideae phenolics have been found in two Spiraeoideae genera; luteolin 7-glucoside, luteolin 7-diglucoside, luteolin 7-rhamnosylglucoside and apigenin 7-glucoside in Exochorda and the dihydrochalcone trilobatin in Sorbaria. The chemotaxonomic evidence is consistent with the hypothesis that the Pomoideae evolved through a process of allopolyploidy from primitive members of the Spiraeoideae and Prunoideae. ... survey&t=0

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