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Development of the pollen grain wall in Canna
Author(s) -
Rowley John R.,
Skvarla John J.
Publication year - 1986
Publication title -
nordic journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.333
H-Index - 33
eISSN - 1756-1051
pISSN - 0107-055X
DOI - 10.1111/j.1756-1051.1986.tb00859.x
Subject(s) - microspore , pollen , biology , botany , tetrad , starch , layering , canna , biophysics , food science , stamen
During the tetrad period spinules form on the Canna L. plasma membrane at intervals of 1–2 μm on a microspore surface of ca. 100 μm 2 . The isolated spinules represent all that there is of a primexine‐like nature. Immediately following loss of the callosic tetrad envelope a channeled, oncus‐like zone forms on the plasma membrane over the entire microspore surface, elevating the spinules. The oncus‐like zone becomes ca. 4 μm thick by microspore mitosis. Intine introduction during the pollen grain period coincides with substantial thinning of the oncus‐like zone and pollen grain enlargement. In the final phases of maturation grains increase further in diameter and become packed with starch and lipoidal material. The oncus‐like zone more than doubles in height necessitating a migration of the boundary of the oncus‐like zone and intine. At pollen grain maturity the thin (ca. 200 nm) surface layer of the oncus‐like zone appears to be compacted or filled in.