Anyway, I dug-out a few old tissue blocks of some Lily anthers from last-year's 'double embedding' trials and made a few sections for use in my staining studies. I've a few nice images that I though you may find interesting as they are sectioned at 8µ and show clearly the bi-nucleate pollen-grains as found in most flowering plants while they are yet to land on a stigma and germinate.
It's then, while travelling through the resultant pollen-tube, that a second sperm-nucleus is produced. The larger 'vegetative' or 'tube nucleus' is responsible for building the pollen-tube - the two sperm nuclei are destined to perform the so-called 'double fertilization' within the egg-sac of the receptive ovule into which the pollen-tube ultimately delivers these two nuclei....
The blue isn't much in evidence in these images - it is mainly concerned with the staining of primary cell walls (non-lignified) and only really features in these images in staining the anther cell-walls. I thought these pollen details may nonetheless be interesting, and the Safranin has made a lovely job of differentiating the pollen's cytoplasm and nuclear material.
Here's a LS of an anther - oriented by way of the double-embedding (agar/wax) technique I studied a while back now. The faintly greenish tinge around the grains is the trace of stain that remained as it often does within the agar matrix that surrounds (but doesn't infiltrate) the tissue.
- ws_lily anther pollen (2).jpg (71.99 KiB) Viewed 3888 times
- ws_lily anther pollen (4).jpg (53.49 KiB) Viewed 3888 times
- ws_lily anther pollen (3).jpg (25.87 KiB) Viewed 3888 times
- ws_lily anther pollen (1).jpg (46.95 KiB) Viewed 3888 times
John B.
