Grid for pollen measurement

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Re: Grid for pollen measurement

by Don » Fri Aug 23, 2019 8:12 pm

There are plenty of protocols for germinating pollen most of which are similar to the one in this linked paper. ... 45tIaEeLyp

The ingredients are

PGM medium:
40 mg/L H3BO3
152 mg/L CaCl2(H2O)
150 g/L-sucrose
7 g/L agar, pH 5.6
incubate at room temperature for 24 hours

The agar is non-essential though plating the pollen makes it easier to focus on. I'm sure David Zlesak or Larry Davis can offer some tips.

Re: Grid for pollen measurement

by mike athy » Fri Aug 23, 2019 5:22 pm

I am very interested in this project and look forward to more pictures of your pollen samples.
Don, what is the process to encourage the pollen to germinate in order to photograph that?
Cheers. Mike

Re: Grid for pollen measurement

by Don » Thu Aug 22, 2019 11:15 pm

Way cool.

An experiment to try would be to germinate some pollen and photograph it with an eye toward determining pollen viability.

Re: Grid for pollen measurement

by jbergeson » Thu Aug 22, 2019 10:43 pm

A couple more pollen pics from a seedling.

The varied size, to me, implied that the rose is triploid.

Note that there are also yellow and white grains. Could the clear/white ones be non viable?

Re: Grid for pollen measurement

by jbergeson » Thu Aug 22, 2019 11:30 am

I’m getting a little better at taking photos from my phone through the pocket microscope. One interesting thing is that some roses’ pollen appears to have a mix of yellow and white grains. Any thoughts?

Re: Grid for pollen measurement

by Roselynn » Wed Aug 14, 2019 10:02 pm

Thanks Joe for the suggestion for this pocket microscope. Got mine in the mail today. Really neat. Here’s some just picked Snow Pavement diploid pollen. Getting the cellphone to take a decent photo was a challenge. It’s more clear/focused to the eye.

Re: Grid for pollen measurement

by jbergeson » Fri Jul 26, 2019 8:04 am

I wish Henry's pollen pics were still up.

Re: Grid for pollen measurement

by Plazbo » Fri Jul 26, 2019 3:22 am

David says 400x towards the end of this thread ... 0&start=60

Re: Grid for pollen measurement

by philip_la » Fri Jul 26, 2019 12:36 am

Cool! Slightly OT, but I'm curious as to what kind of magnification would be required to view root-squashes to determine ploidy? I'm assuming that's requires a heckuva lot more magnification?

Re: Grid for pollen measurement

by Margit Schowalter » Thu Jul 25, 2019 11:40 am

Thanks Joe. I often use frozen pollen and check for viability with a standard microscope. The pocket microscope will sure be faster than fussing around preparing slides.

Re: Grid for pollen measurement

by Plazbo » Tue Jul 23, 2019 10:15 pm

Thank you for this thread, I never realised it'd be so easy an inexpensive.

Re: Grid for pollen measurement

by jbergeson » Tue Jul 23, 2019 5:57 pm

OK, the "microscope" that I ordered to work with my iPhone is a disappointment. It doesn't focus well and hangs up (wifi connected).

Tbat's this one:

But the other pocket scope I ordered is really cool. This one:

I highly recommend that second pocket scope. It's only $13 on Amazon Prime. The ideal surface upon which to view pollen is the top of a Folger's coffee can lid. The black plastic is textured slighly so if you have a good blob of pollen you can smear it with your finger to distribute the pollen grains evenly. It is magical to see the translucent golden eggs under 120X magnification.

I think it could help determine if a plant is diploid, triploid, or tetraploid. Triploids will usually have mixed pollen sizes (correct me if I'm wrong). I have a rugosa x Miracle on the Hudson seedling which I suspected was a diploid due to it retaining strong rugosa characteristics while appearing to be a hybrid. Sure enough the pollen grains are beautiful, well-shaped, and uniform. (now how to move forward? what was I wanting a rugosa x modern hybrid for again?)

It is useful for checking out if my first generation rugosa x modern hybrids, which are often sterile, have any good pollen. Seems like that could save some wasted effort.

I just wish I could find something that made it easy to take pics of pollen. I want to document and share photos of various roses' pollen. The attached photo is just from putting my phone over the eyepiece of the pocket scope.

Re: Grid for pollen measurement

by jbergeson » Mon Jul 22, 2019 8:41 am

Thanks, Henry.

Re: Grid for pollen measurement

by henry kuska » Mon Jul 22, 2019 12:00 am

Use the keywords microscopic calibration in an ebay search.

Grid for pollen measurement

by jbergeson » Sun Jul 21, 2019 11:40 pm

A few years ago a friend who is a professor of genetics gave me the gift of a pocket microscope. It is just an aluminum tube the diameter of a pen and about four inches long and you just look into it and rock it forward or back to focus. A black Folgers coffee lid is an ideal substrate for viewing the pollen, and I hold my iPhone's flashlight to the side to illuminate it. It is 40X magnification.

The microscope has been handy and fun. If the pollen grains look like uniform, plump, eggs I can be pretty sure that the pollen is fertile and the rose producing it is not a triploid. On the other hand, some roses produce pollen that is "glumpy" and has nary an egg-like pollen grain to be seen. In my experience such pollen will be difficult or impossible to work with. So if I have a promising seedling and want to breed with it, my first step is to look at the pollen under the microscope. This has been really handy for first generation rugosa x modern seedlings, which are often but not always completely sterile.

I just ordered a microscope that will hopefully hook up to my phone, give me a little more magnification, and allow me to easily snap pics of different pollens.

I hopped on the internet to order a microscopic grid plate. Perhaps a black glass surface with tiny, microscopic grid lines of 0.1 mm spacing. What the heck? There appears to be no such thing on the internet. It seems like such a no-brainer for eyeballing the relative diameter of tiny objects such as pollen grains. I'd like to photograph the pollen of different roses against such a grid so it would be easy to compare the relative diameter of different roses' pollen.

If you run across such a grid plate, please let me know. I will reward you with many photos of pollen grains.