A row of sporogenous
cells derived from archesporial cells produced a large number of microspore mother cells after several mitotic divisions (Fig.
Furthermore periclinal divisions of sporogenous
cells resulted in the formation of pollen mother cells in S.striata.
Cytological observation of CMS-D8 also suggested that sterility resulted from sporophytic dysfunction in that degeneration of sporogenous
tissues occurred before meiosis (Black, 1997).
In all 3 yr of this study, plants containing sporogenous
tissue were observed only during November through April [ILLUSTRATION FOR FIGURE 5A, B OMITTED].
PMCs were generated from primary sporogenous
cells simultaneously with the development of microsporangium wall.
One hypothesis is that the tapetum has the vestigial capacity to polymerize sporopollenin because it shares a phylogenetically identical origin with the sporogenous
tissue (Hesse, 1986).
Results showed that citric acid had an inhibitory effect on sporogenous
5-8; 13-15; 20; 22-24) plants displayed all of the stages of microsporogenesis and microgametogenesis, from sporogenous
mass stage (premeiosis) to engorged pollen stage near anthesis.
Archesporium produces a parietal cell and a primary sporogenous
Within the anther, male sporogenous
cells differentiate and undergo meiosis to produce microspores, which give rise to pollen grains, whereas other cell types contribute to pollen maturation, protection, or dispersion .
All of these cells were initially sporogenous
. That is, chromosome-reduction initially occurred in every cell of the intercalated diploid generation.
They are divided periclinally, cause to formation of inner sporogenous
cells and outer parietal cells.