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Germination
Early growth and tillering
Stem elongation
Wheat apex development
Flowering and fertilisation
Pollen release
Grain growth 1 to 4 days
Whole grain photographs
Embryo sac: events inside
Embryo sac: wall changes
Embryo micrographs
Grain growth 4 to 10 days
Cell layers inside a grain
Grain filling 11 to 16 days
Grain filling 17 to 21 days
Grain filling 21 to 30 days
Development of the embryo
Dry down 30 to 40 days
How we grew the plants
Photography and microscopy
DAYS = days after flowering
![]() | This transverse section is from a 4 day old grain. During this phase the outer integument degenerates while a cuticle develops on the inner integument. The nucellus degenerates until only its cuticle and epidermis remain. In some areas of grain, but not all, we can see tube cells and cross cells. The Cell Layers inside the Grain are described in detail in a separate section. |
![]() | There are complex changes in the structure of the embryo sac wall during the first days of grain growth. This transverse section is from a 2 day old grain and shows the cell layers near the ventral groove. Not all the layers are labelled. From the inside: nucellus, nucellar epidermis (arrowed), inner integument (two cells thick), outer integument (two cells thick), tube cells, cross cells, maternal pericarp. The Cell Layers inside the Grain are described in detail in a separate section. |
![]() | This transverse section of the embryo sac wall is taken from the flank of the grain at 3 days after fertilization. One nucleus from 'free division' can be seen, but it has no cell walls associated. |