OSR pollen

[thada1]

Two questions as a relative novice to pollen imaging. I got a x1000 image of OSR pollen yesterday, just by shaking onto a slide and using immersion oil. The grains are rugby ball shaped, and there's a hint of the netting pattern on the exine that you can see with SEM (I have a EM friend who gets bad hayfever and likes to know his enemy). I also prepped a fuchsin red stained glycerine slide. When I look at that this evening, the grains are essentially spherical, albeit a nice shade of purple.

Q1. How well should I expect to image the exine pattterning. If I squint I can see a little, and of course you get a better impression with a moving fine focus, but so far no luck with z-stacking software.

Q2. I was surprised how different the pollen looked after resting in aqueous glycerin for 24 hrs. How much swelling, shape change should I expect? So far, I've always used the stain/glycerin approach so haven't compared plain.v.treated.

 

[BKF Admin]

I think Bcrazy is on his Hols,I am sure we have other members who could answer though.

 

[Bcrazy]

Hi thada1
I am afraid that I must disagree with you when you say the picture shows OSR pollen grains.
I think these may bee from Dwarf gentian Gentianella campestris or Swertia perennis.
OSR pollen grains are round not oval.
Great shot of the grains but you give no indication of size of grain. OSR is between 20-30 um (microns).
I have enclosed two flowers that I think might have been the source of the grains.

I will try to get a shot of OSR pollen grains for you.

Regards;

 

[Bcrazy]

Hold the press, I have got it wrong
The picture does show OSR but the grain in question is a dried pollen grain
Shown are three different views of the same grain,

My apologies to you all .

Regards;

 

[Bcrazy]

Nothing is going right today.

 

[thada1]

glad to see we agree - I was worried for a moment that I'd managed to contaminate my sample. So, rugby ball shaped grains are dried-out OSR pollen. That makes sense for the SEM pictures (as per my pdf, and yours). Apologies for lack of scale - I was too mean to buy my own graticule, so I haven't yet calibrated my 'scope at 1000x. "By eye", the long axis is ~10u. The image was taken just by adding some immersion oil to some OSR pollen on a clean slide. Is it possible that the oil has dessicated the pollen?

Here's my standard preparation of OSR - the disk is ~10u diameter. Again, there are hints of the exine pattern; how much better resolution might the fine structure have, on an expensive microscope - one that is better than my Brunel DM30?