Talk:Pollen

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This is an old revision of this page, as edited by 66.167.61.217 (talk) at 21:39, 23 May 2010 (→‎Pecan pollen allergy related to intensity of exposure PMID 8194783: new section). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

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lots of bees or wasps like pollen they find it good for there hive they mainhly use it to produce honey which is verry sweet !! —Preceding unsigned comment added by 92.233.174.148 (talk) 16:41, 27 November 2008 (UTC)[reply]

Number of cells in the pollen grain

The introduction asserts that there are three, but a later paragraph says that there is only one? Jonathan Webley 07:29, 17 August 2005 (UTC)[reply]

Nutritional values

This statment, as written needs editing, but I am not yet ready to do this myself.

"Pollen is sold as a nutritional supplement, marketed as "bee pollen" (even though it is of course from flowers).

It has no biological effect at all,"

This last phrase is quite debatable, and certainly does not represent a neutral point of view. Pollinator 03:42, 19 Sep 2003 (UTC)

..."except in triggering allergic reactions."

This depends on what pollens are present, and it is also debatable whether consuming the pollens orally would have the same effect on the body as breathing them. Pollinator 03:42, 19 Sep 2003 (UTC)

There was no response to my previous comment, so I simply removed the misleading line.Pollinator 18:54, 21 Oct 2003 (UTC)

While it is debatable, here's a source (citing several studies) that backs the information up; I'm sure it can be reintegrated in a more NPOV-appropriate way. [1] --LostLeviathan 01:14, 20 Dec 2004 (UTC)
Surely it would be worth adding a word about what benefits are claimed for eating pollen, and also the grounds on which these benefits are considered fallacious by others. I cam eto the entry looking for something on this and was surprised to find only the fact that it is "sold as a nutritional supplement", which didn't help much. Flapdragon 14:12, 23 July 2005 (UTC)[reply]
Sorry for taking over two years to respond Pollinator! :-D I've added the phrase in, but highly toned it down. I will try to look for some evidence on the subject when i get time. Tristanb 12:13, 15 November 2005 (UTC)[reply]

There are a great deal of positive studies on Bee Pollen. Not all of them are just empty claims. [2] [3] [4]

Featured pictures

Note that this relatively short article includes TWO featured pictures. Apparently this topic is better explained with photons than words. -- [[User:Solitude|Solitude\talk]] 15:50, Nov 2, 2004 (UTC)

You could replace the bee in the hay-fever section with Image:Bumblebee closeup.jpg and make it three for three ;-) -- Solipsist 19:25, 3 Nov 2004 (UTC)

bg 81.109.148.167 18:41, 21 May 2006 (UTC)[reply]

Is this true?

I read somewhere that "pollen lasts forever". It was in a respectable book so I assume it's true. Anyone else read this? Michaelritchie200 19:21, 28 August 2006 (UTC)[reply]

Sporopollenin is very sturdy and not easily degraded. The rest of the pollen grain decays like any other plant part.--Curtis Clark 04:47, 31 August 2006 (UTC)[reply]
Thanks. Michaelritchie200 18:26, 3 September 2006 (UTC)[reply]

Plant sperm

It would be nice to have an article on the sperm cells contained in the pollen and to link there.

To what extend do "plant sperm" differ from animal sperm?

I know about bracken spermatozoa by the papers from CJ Brokaw (J. exp. Biol., 1955, 57, ...), they differ somewhat in morphology from the animal morphology and have e.g. several flagella. --193.175.8.13 14:53, 26 October 2006 (UTC)[reply]

Or none, as in the conifers and flowering plants.--Curtis Clark 03:52, 31 May 2007 (UTC)[reply]

Ploidy

It should be added somewhere that pollen is the haploid stage of development of a plant. TiCPU 02:32, 11 December 2006 (UTC)[reply]

That's implicit in the fact that pollen is a gametophyte.--Curtis Clark 05:06, 11 December 2006 (UTC)[reply]
the article leaves me confused whether the pollen grain is entirely gametophyte or carries with it some sporophyte casing. Why the distinction between vegetative cells and generative cells drawn in the way it is? Put another way, how am I wrong in saying: the sporophyte (plant we see) produces a spore which 'grows' into the gametophyte pollen grain which continues to grow on pollination (pollen tube) and finally produces gametes which it delivers in the ovule? Jagdfeld (talk) 13:29, 26 January 2008 (UTC)[reply]
The exine is produced by the sporophyte, iirc, but it is not cellular. The spore grows into a pollen grain in the same way that a zygote grew into you or I, and, if it's helpful, you could think of the pollen grain and pollen tube as different phases in the life of a male gametophyte.--Curtis Clark (talk) 15:26, 26 January 2008 (UTC)[reply]
do you think the article could be clearer? The paragraph "The structure of pollen" - 1st para - is obscure to someone trying to get things clear the mind.---- Each pollen grain (gametophyte) contains vegetative cells (well it grows!)(only one in most flowering plants but several in other seed plants) only one cell??? and a generative cell containing containting??? a tube nucleus (that produces the pollen tube) and a generative nucleus (2 nuclei??)(that divides to form the two sperm cells). The group of cells is surrounded by a cellulose cell wall and a thick, tough outer wall made of sporopollenin (from the sporophyte). Jagdfeld (talk) 15:50, 26 January 2008 (UTC)[reply]
I made a start on this. Does it help?--Curtis Clark (talk) 19:56, 26 January 2008 (UTC)[reply]

Pollen classification

Only 'sulcate' and 'colpate' form pollen are mentioned it seems, but a primary reference (http://www.blackwell-synergy.com/doi/abs/10.1111/j.1469-8137.1972.tb04826.x) refers to a third type, 'porate'. I'm wondering whether this third type is no longer recognized, or is this just a minor omission from the text. --User:Ceyockey (talk to me) 03:22, 30 May 2007 (UTC)[reply]

Phylogenetically speaking, porate pollen is derived from colpate, but it probably needs to be mentioned.--Curtis Clark 04:21, 30 May 2007 (UTC)[reply]
Read a bit further into that article. After defining colpate, sulcate, and porate, it says: "regarding the relative advancement of porate and colpate pollen, the evidence is less convincing. What seems to be more important is the number of apertures, regardless of whether they are pores or colpi". But I'm over my head in trying to go into much detail (either about pollen anatomy, or about its significance to phylogeny or other topics). Do keep in mind that the article is from 1972, and at least with respect to the phylogeny aspect, it was at/near the beginning of this whole "tricolpate" classification. Kingdon 20:51, 30 May 2007 (UTC)[reply]
My understanding is that porate pollen is only found among the eudicots, and that the eudicots are ancestrally colpate (by outgroup comparison). This doesn't mean that in any given group, porate pollen is derived relative to colpate pollen, though, since the transition can evidently work both directions.--Curtis Clark 03:50, 31 May 2007 (UTC)[reply]

Pollin is transported to the other flowers by bees

"see photomicrograph at right", yet the caption said the image was made by a scanning electron micrograph. Isn't the image, therefore, an electron micrograph?


Yes, thank you for pointing that out. your comments will be seen sooner if they are placed at the bottom of the page, older text tends to be at the top of the page and many people do not bother to look up that far on any given talk page, again thank you for pointing out the issue. Hardyplants 23:58, 18 September 2007 (UTC)[reply]

Some possible improvements

Don't ask to use that impossible-to-use to-do template. I think this page could be improved a lot

  • Rename 'Structure of pollen' to 'Structure' (what are we talking about?)
  • Create a 'Fertilisation' section after 'Pollination' and move there the first paragraph of 'Structure' and the last of 'Pollination', making integrations and cleanup
  • Create a 'Production' section after 'Fertilisation' and move there part of the second paragraph of 'Structure'
  • Expand the 'Structure' section by adding something on the classification (possible source: Strasburger, Lehrbuch der Botanik für Hochschulen. Pictures?)
  • Err... the sections are a mess, actually. They need a deep rearrangement. Definition, Structure, Pollination, Fertilisation, Production, Evolution, Importance for the plants, Importance in the ecosystems, Importance for humans...
  • Correct the first paragraph in 'Structure'. That situation is only the typical one.
  • Move something to Palynology and vice versa, take something from the articles in 'See also'
  • Have a look to the pages in the other languages. Something useful usually comes out.

Aelwyn 19:23, 24 September 2007 (UTC)[reply]

All good suggestions. The main other thing which springs to mind is how the structure of pollen relates to its function. For example, wind-pollinated plants (see anemophily) will have a dusty pollen; goldenrod and other plants will have sticky pollen which relates to the ways that insects transmit their pollen, and so on. There is some material in the 'Pollination' section, but I don't really know enough to say how incomplete it is. Kingdon 21:25, 24 September 2007 (UTC)[reply]
One more (moved here from Wikipedia:WikiProject Plants/Collaboration): Given that a certain amount of this article is from 1911, what is new (or newly important) since then? I made a stab at tricolpate pollen (and its significance for angiosperm classification) but I don't have the knowledge to do that thoroughly, or to know what other topics like that exist. Kingdon 18:03, 26 September 2007 (UTC)[reply]

Illustration of pollen grains?

It'd be great if possible to get illustrations of pollen grains, particularly to illustrate the colpate/sulcate features. Of course it would require expensive equipment to show real examples, but maybe a drawing or diagram or 3D model? Dcoetzee 00:20, 30 July 2009 (UTC)[reply]

I've got some real examples (SEM), but they are 4×5 negatives and contact prints, and are packed away in a box somewhere. If I can find some readily, I'll scan....--Curtis Clark (talk) 02:10, 30 July 2009 (UTC)[reply]

Hay fever section: "globalize/USA" tag

The section on hay fever is written in such a way that one would think that hay fever only exists in the United States. It only cites American facts, figures, concerns and cultural references. But hay fever may occur anywhere in the temperate zones (in tropical areas, hay fever is less common, because flowers bloom all year, so there is not a peak concentration of pollen in the spring, and people also become desensitized with the small but constant amounts of pollen). Therefore, I have added the "globalize/USA" tag to call the reader's (and authors') attention to what appeared to me as an excessive American bias on the topic. --UrsoBR (talk) 07:20, 10 April 2010 (UTC)[reply]

Pecan pollen allergy related to intensity of exposure PMID 8194783

PMID 8194783

Waisel Y, Keynan N, Gil T, Tayar D, Bezerano A, Goldberg A, Geller-Bernstein C, Dolev Z, Tamir R, Levy I, et al.

[Allergic responses to date palm and pecan pollen in Israel]

[Article in Hebrew] Harefuah. 1994 Mar 15;126(6):305-10, 368. Tel Aviv University. Abstract

Date palm (Phoenix dactylifera) and pecan (Carya illinoensis) trees are commonly planted in Israel for fruit, for shade, or as ornamental plants. Pollen grains of both species are allergenic; however, the extent of exposure to such pollen and the incidence of allergic response have not been studied here. We therefore investigated skin-test responses to pollen extracts of 12 varieties of palm and 9 of pecan in 705 allergic patients living in 3 cities and 19 rural settlements. Sensitivity to the pollen extracts of both species was much higher among residents of rural than of urban communities. Moreover, there was a definite relationship between the abundance of these trees in a region and the incidence of skin responders to their pollen. Sensitivity was frequent in settlements rich in these 2 species, such as those with nearby commercial date or pecan plantations. In general, sensitivity to date pollen extracts was lower than to pecan. However, differences in skin responses to pollen extracts of various clones were substantiated. Air sampling revealed that pollen pollution decreased considerably with distance from the trees. At approximately 100 m from a source concentrations of airborne pollen were low. Since planting of male palm and pecan trees in population centers would increase pollen pollution, it should be avoided.