May 1 ~ May 3###Meiosis of microspore mother cell stage###Nucelli continue projection
A row of sporogenous cells derived from archesporial cells produced a large number of microspore mother cells after several mitotic divisions (Fig.
Each microspore mother cell undergoes meiosis; during which M.M.C undergo successive type.
microspore mother cells (Microsporocytes), were also detectable (Fig 1B).
There was a significant correlation between microspore mother cell
divisions and anther's tapetum development that is coincides with other reports for dicotyledonous plants [7,10,6].
microspore mother cell
: Diploid mother cell that will go through meiosis to produce the (4) haploid microspores.
In Hordeum vulgare, plastids are scarce in the microspore mother cell
(2.8 [+ or -] 0.3 plastids per 100 [micro][m.sup.2] cytoplasm), and they intensely multiply later on, during early vacuolation, reaching up to 72.3 [+ or -] 2.4 plastids per 100 [micro][m.sup.2] cytoplasm before the first pollen mitosis (Caredda et al., 2000).
Although the anther ontogeny and microsporogenesis in S.striata is a continuous process for descriptive purposes of the structure and ultrastructural details, we distinguished five stages of development: microspore mother cell
stage followed by meiosis, tetrads, free young microspores, vacuolated pollen, and mature pollen grains at dehiscence.
The cells in the sporogenous areas that undergo meiosis are called microspore mother cells
, or microsporocytes.
The distinctive shape of the microspore, with its sharply angled proximal ridge, is a result of the developmental pattern of the microspore mother cells
. In Isoetes setacea Lam., the paraexospore (sensu Tryon & Lugardon, 1991) forms the outer layer of the microspore and is then covered by the perispore.
The meiotic division in the MMC is synchronic with the microspore mother cells
In very young buds, the head of stamen primordia protrudes slightly and microspore mother cells
are massive diploid and detectable (fig 2A).