WheatBP

Back to cerealsdbDevelopment Home Germination Early growth and tillering Stem elongation Wheat apex development Flowering and fertilisation Pollen release Grain growth 1 to 4 days Grain growth 4 to 10 days Whole grain photographs Endosperm cellularisation Embryo sac: wall changes Embryo micrographs
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

Grain growth 4 to 10 days

Embryo sac: wall changes

	This high magnification longitudinal section through the upper end of the embryo sac shows the development of the dorsal side of the grain is very different from the ventral groove area. 5 days after flowering.
	The first completed endosperm cells are on the outside and more cells walls grow toward the centre. The nucellus degenerates during development, leaving only its epidermis which later becomes compressed.
	A different part of the embryo sac wall at 7 days after flowering. The timing of changes in these cell layers depends on their position on the grain surface.
	High magnification shows details of the embryo sac wall at 6 days after flowering. There are complex changes in the cell layers surrounding the embryo sac, between the endosperm (inside) and the parenchyma cells of the pericarp (outside). Some layers will disappear completely; others will remain only as a cuticle. Only the inner integument is viable through all the grain development stages.

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