Loading ...
Sorry, an error occurred while loading the content.

Fwd: Re: Pollen photos

Expand Messages
  • Peter Bernhardt
    I do not think that acetolysis is the best technique for either pollination biologists or beekeepers and should be used only as a last resort. It was
    Message 1 of 1 , Aug 20, 2013
    I do not think that acetolysis is the best technique for either pollination biologists or beekeepers and should be used only as a last resort.  It was developed originally to "clean" off dust accumulated on grains dispersed by the wind or dirt in bog or soil deposits of fossil pollen.  Acetolysis is good for identifying "tricky grains" in which classification is based on structural differences in the layers that make up the pollen wall (sexine, nexine, intine). Acetolysis also destroys some of the most useful, outer characters for easy identification.  It knocks off pollen caps (opercula), some spines and removes the oil droplets that cling to the pollen wall.  The color of those oil droplets often let you discriminate between different species in the bean family loved by honeybees.  

    If you keep a dated collection of pollen from known flowers, either as mounted glass slides or micrographs,  it should be much easier to match the pollen load on the bee with flowering species in the area.  The recipe for Calberla's fluid is on the web and in a number of books.  Pollen walls are pretty in pink.  Check out these two photos taken by Prof. Ren Zong-Xin in the Bernhardt/Meier lab.  They are at different magnifications.  The higher magnification is of grains of spring beauty (Calytonia virginica).  Note that two grains "popped" and are oozing cytoplasm.  Note also that the same grain may vary when observed from different angles.  The second, at lower magnification, was taken from a bee collected on yellow star grass (Hypoxis hirsuta).  The yellow star grass is a smooth "football" with a long transparent operculum cap.  The two balls in the center (full of pores and ridges) indicate that the same bee visited chickweed (Cerasitum) before visiting the star grass.  It's unlikely that acetolysis would preserve all of these, outer-surface details.  

    Peter Bernhardt  

    -




Your message has been successfully submitted and would be delivered to recipients shortly.