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.
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].
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 .
The further elaboration of the sporophyte was accompanied by the sterilization of formerly sporogenous
cells to perform vegetative and other functions.
They are divided periclinally, cause to formation of inner sporogenous
cells and outer parietal cells.
This antithetic view holds that more elaborate sporophytes developed by progressive sterilization, and further vegetative development, of originally almost totally sporogenous
When stamens fail to develop into the above-mentioned sporogenous
structures but retain the same characteristics of microsporophylls, they are usually referred to as sterile stamens or staminodes (e.