ibclogo XVI International Botanical Congess


Abstract Number: 2233
Poster No. = 1673


ULTRASTRUCTURAL STUDIES OF THE PLASMODIAL TAPETUM OF ABUTILON PICTUM (MALVACEAE)


Galati, B. , Strittmatter, L. & Monacci, F.Dpto. Cs. Biológicas, F.C.E.y N., UBA, Pab.II, p.4 (1428) Buenos Aires, Argentina


Four stages of development in the plasmodial tapetum of Abutilum pictum have been identified and studied with TEM. At the stage of free microspore the tapetal cells still maintain their individuality and Ubisch bodies could be seen attached to a peritapetal membrane. The protoplasts of the tapetal cells fuse to form a periplasmodium in the anther locus at the young pollen grain stage.Once the pollen grain is mature, the plasmodium is consumed and only the peritapetal membrane with Ubisch bodies remains, enclosing the pollen grains.The orbicules are pear shaped, and resemble the spinules in the exine surface. Ultrastructuraly they are solid without a central core. The occurrence of Ubisch bodies in a peritapetal membrane derived from a plasmodial tapetum has not been reported before.


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