The ratings used in the analysis were 1 = 100% fertile, 2 = 25% pollen sac
nondehiscence, 3 = 50% nondehiscence, 4 = 75% nondehiscence, and 5 = total sterility .
Each pollen sac
was concluded of peripheral cells forming an undifferentiated walls and a mass of uniformed cells (archeosporial cells) (fig 1A).
caryopsises dehiscent DNA fingerprinting drupe endocarp exocarp [F.sub.1] hybrid gamete gene homozygote inbred indehiscent mesocarp nut open-pollinated seeds parthenocarpy perfect pericarp pollen sac
quantitative trait self-incompatible self-sterile tube nucleus zygote
In this case, a male-derived embryo was obtained after emasculation of the female parental, irradiation of the pollen sac
, and pollination with untreated pollen (Ehrensberger, 1948; Gerassimova, 1936).
At this stage, the wall surrounding the four microspore cells dissolve and the microspores in the pollen sac
They are formed both in the cells of the tapetum and in the locule of the pollen sac
(Rowley et al., 1959).
Bumblebees will also visit the larger; more open snowdrop flowerheads and reverse out with bright orange "dots" on their legs, their pollen sacs
being full of their haul.
When Endress and Doyle (2009) added Ceratophyllum to a revised version of this morphological data set, with other taxa constrained to an arrangement based mainly on Doyle and Endress (2000), Ceratophyllum and Chloranthaceae formed a clade supported by five synapomorphies: sessile flowers, one stamen, embedded pollen sacs
, one carpel, and orthotropous ovule.
Pollen was visible in the pollen sacs
on the legs of the bees.
The epidermis and connective ground tissue in the anther of the sterile plants contained abundant starch (Fig.2), and there were 4 pollen sacs
in both sterile and fertile anthers (Fig.
Y-shaped pollen sacs
, located at the bottom of the flower hoods, can trap smaller insects.