The Feasibility Study on the Prediction of Ploidy Levels Bas

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The Feasibility Study on the Prediction of Ploidy Levels Bas

Postby henry kuska » Tue Oct 17, 2017 10:49 am

Title: "The Feasibility Study on the Prediction of Ploidy Levels Base on Pollen Dimensions in Rosa"

See:

https://profdoc.um.ac.ir/articles/a/1064651.pdf
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Re: The Feasibility Study on the Prediction of Ploidy Levels

Postby johannes p » Wed Oct 18, 2017 5:16 pm

Is there any indication which roses were used? I use pollen size with rugosa/woodsii. I am curious as to diversity. No chance of a copy of this paper eh? Johannes
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Re: The Feasibility Study on the Prediction of Ploidy Levels

Postby henry kuska » Wed Oct 18, 2017 10:06 pm

The following was stated: "No chance of a copy of this paper eh? Johannes"

Didn't the link provide you with the full copy?
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Re: The Feasibility Study on the Prediction of Ploidy Levels

Postby Margit Schowalter » Thu Oct 19, 2017 12:55 pm

Thanks for the link Henry.
I regularly check pollen diameter of roses intended for hybridizing. Sometimes the pollen sizes are fairly consistent and the measurements predict the ploidy easily. Other times the size of pollen grains are highly variable and the ploidy isn't obvious. I suspect it would be easier to determine if one had a large enough sample of grains to examine. I find the effort to measure the pollen worthwhile as I have often been surprised by the quality or lack of quality of the grains. Sometimes a rose with copious amounts of pollen turns out to have mostly dead distorted cells when examined under the microscope. This is good to know before making the cross. Also, I have learned that the discovery of dead distorted pollen is not always what it seems. I have taken a second sample from the plant a week later and found good looking viable appearing grains. For me, the microscope is an valuable tool and I need all the help I can get!
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Re: The Feasibility Study on the Prediction of Ploidy Levels

Postby david zlesak » Sun Oct 22, 2017 12:19 am

I greatly value Dr. Kermani and her contributions. I'm confused by this paper. Questions I have include: did her students just look at the 5 genotypes listed (I assume so), why didn't they hydrate the pollen to measure it, and why didn't they discuss Caninae meiosis and its impact on the ploidy of the pollen in their 5x R. canina? Also there are unfortunately typos with some that may be leading to misunderstandings. For instance, in Table 2, there are two groups of data columns listed as pollen width. I suspect the first group of columns may be pollen length. It is interesting that R. persica seems to have relatively large pollen for being diploid.

This is just my impression.
The pollen lengths seems to be very comparable to diameters of round hydrated pollen for expected pollen ploidy. I may be wrong, but it seems from what I understand they looked at just the 5 listed genotypes and measured ~100 grains per plant for their analysis.

Pollen from typical diploids and Caninae section species that produce 1x pollen as well with hydrated pollen is typically about 32 microns. They found pollen length from R. canina to be 31.35 microns, which seems typical. Oddly, R. persica (a diploid) produced longer than expected pollen at 41.19. It would be interesting to know if this species, which is very different than other roses, has larger pollen in general.

Pollen that is 2x (from 4x parents) has been about 38-41 microns for me with hydrated pollen, and they found 39.66- also typical. Hexaploids that have meiosis with 3x pollen is in the mid 40s with hydrated pollen and they found 43.92. Triploids have had more variability within and between triploid parents and often they have a mean closer to that of pollen of tetraploids than diploids, and they found 36.64 microns, also typical.

Everything seems pretty consistent to me and predictable for pollen size, except their R. persica seems to be grouping with pollen size more typical for tetraploids. Perhaps the odd diameter of R. persica and not accounting for the unique meiosis of R. canina and its pollen ploidy (maybe I'm overlooking or misunderstanding if they do account for it) are the keys leading to their conclusion pollen size is not very predictable of ploidy.
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Re: The Feasibility Study on the Prediction of Ploidy Levels

Postby johannes p » Mon Nov 06, 2017 7:02 pm

I don’t hydrate sometimes when I want to reuse the pollen and there is only scarce amounts.
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