Dear Plant-edders,
While we're on the subject of the embryo sac, does anyone know for sure
if the polar nuclei of Lilium unite before the sperm arrives? I re-read
Bold, Alexopoulos, and Delevoryas, but it was not stated. The
illustration of Lilium shows separate nuclei, but in discussing the
general case the authors state that these (polar nuclei) may unite before
or at fertilization to form the secondary nucleus.
I am also puzzled by the linear arrangement of antipodals in the same
illustration (one above the other in alignment with the long axis of the
embryo sac). I have seen them that way in Erigeron, but my experience
with Lilium is in a more triangular or horizontal arrangement at right
angles with the long axis. Is the linear arrangement simply the earlier
stage and the horizontal arrangement the final position?
Thank you for any information to clarify these points.
Janice
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Janice M. Glime, Professor
Department of Biological Sciences
Michigan Technological University
Houghton, MI 49931-1295
jmglime at mtu.edu
906-487-2546
FAX 906-487-3167
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