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A Rose Man 
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This variety has been used in studies on blackspot resistance in diploid roses and is listed as a R. wichuraiana hybrid. So it seems more likely the parentage is incorrectly reported given that these studies have sequenced the rose.
Another possibility is that there are two different varieties in circulation under this name. One being diploid, the other tetraploid.
But either way, given the commonness of misreported pedigree in cultivars I would be more inclined to believe the report that has been sequenced fully for use in studies over an assumption based on reported parentage until further results have been obtained to settle the matter one way or another
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Well, I'm more inclined to say that the studies used an incorrectly labeled rose. R. carolina and Hugh Dickson are both tetraploid, and neither carry R. wichur(ai)ana. Sure, they could very well have sequenced the rose, but if "the rose" they sequenced wasn't this one, then the results wouldn't apply to this rose. And simply looking at the rose itself, I see no indication of R. wichur(ai)ana ancestry -- blooms are not clustered, habit is not lax, and foliage is not "wich-y".
J06-20-14-3 -- what does this reference? I would like to see the entire study -- all I can read is a one paragraph summary posted in the references.
~Chris
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#2 of 2 posted
29 OCT by
jedmar
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The full article plus the article from which the statement is derived (Characterization of Partial Resistance to Black Spot Disease of Rosa sp.) are available online. Both are too technical to include in HMF
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"Oso Easy Lemon Zest® MHCREC 2.35 ± 0.02 4 0.59"
Tetraploid, too. I guess one cultivar can have multiple ploidy depending on where the tissue (root, leaflet, or pollen) was taken, as well as if it mutated and spread by mass industrial production. Sometimes simply unstable, as well.
Or that conventional measurement methods are reliable in almost all cases, but not all.
I wish this study had included Tropicana, Red Tropicana, Super Star Supreme, and/or Climbing Tropicana. Tropicana is a unique case of a triploid behaving as a tetraploid, that readily gives very large flowers and large plants, and small flowers with small plants to its kin.
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#1 of 6 posted
22 DEC by
jedmar
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Some of the ploidy stated in this publication differ from that of other sources. The method used is Flow cytometry to get an estimate. Only a few cultivars have been "confirmed with microscopy". This might be a reason for the deviations.
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I'm going to hold off on changing ploidy as currently stated until we get further confirmation.
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#3 of 6 posted
23 DEC by
jedmar
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The article of Harmon, Byrne et al. on Cytogenetics etc. refers to two articles by David Zlesak, from where the chomosome counts came.
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I've corresponded with David.
He attempted to clarify the situation but results were posted prematurely.
Until we establish clones were identical results are in doubt.
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Given that the study that estimated it to be triploid used flow cytometry to determine the ploidy, a far less accurate method than direct counts I’d be inclined to believe it’s diploid. And considering the parentage tree it’s not really surprising. Both parents are possible triploids and they could have easily produced a diploid seedling when crossed
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Breeds like a diploid too.
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Does anyone have any idea as to where the ploidy information originated please.
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Has anyone tested the ploidy for this rose? I have wondered if it is a tetraploid mutation.
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David Zlesak reported it as being triploid in 'Pollen diameter and guard cell length as predictors of ploidy in diverse rose cultivars, species, and breeding lines'
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Thanks. Interesting. Makes me wonder what exactly mutated for the new phenotype to spring up. Usually sports are less novel, like strictly a change in color for one genetic reason or another.
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