Summary
The overall morphology of the developing wheat embryo in relation to its neighbouring tissues is described. The embryo is “isolated” early in development, but appears to be a powerful sink for nutrients. It is supplied initially by hydrolysis of the nucellar parenchyma and later by hydrolysis of neighbouring endosperm cells, which are completely digested. Later on, the nucellar epidermis forms specialised cells that may be transfer cells opposite the groove at the base of the embryo. The accumulation of starch and protein appears to begin first in the basal tissues of the scutellum and coleorhiza.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bradbury, D., Cull, I. M., Macmasters, M. M., 1956a: Structure of the mature wheat kernel. I. Gross anatomy and relationship of the parts. Cereal Chem.33, 329–342.
—,Macmasters, M. M., Cull, I. M., 1956b: Structure of the mature wheat kernel. II. Microscopic structure of pericarp, seed coat and other coverings of the endosperm and germ of hard red winter wheat. Cereal Chem.33, 342–360.
— — —, 1956c: Structure of the mature wheat kernel. III. Microscopic structure of the endosperm of hard red winter wheat. Cereal Chem.33, 361–373.
— — —, 1956d: Structure of the mature wheat kernel. IV. Microscopic structure of the germ of hard red winter wheat. Cereal Chem.33, 373–391.
Brown, H. T., Morris, G. H., 1890: Researches on the germination of someGramineae. J. chem. Soc. Trans.57, 458–528.
Feder, N., O'Brien, T. P., 1968: Plant Microtechnique: some principles and new methods. Amer. J. Bot.55, 123–142.
Fulcher, R. G., 1972: Observations on the aleurone layer with emphasis on wheat. Ph.D. Thesis, Monash University.
Johansen, D. A., 1950: Plant Embryology. Embryology of the Spermatophyta. Waltham, Mass.: Chronica Botanica Co.
Krauss, L., 1933: Entwicklungsgeschichte der Früchte vonHordeum, Triticum, Bromus undPoa mit besonderer Berücksichtigung ihrer Samenschalen. Jb. wiss Bot.77, 733–808.
Mares, D. J., Norstog, K., Stone, B. A., 1975: Early stages in the development of wheat endosperm. I. The change from free nuclear to cellular endosperm. Aust. J. Bot.23, 311–326.
—,Stone, B. A., Jeffrey, C., Norstog, K., 1977: Early stages in the development of wheat endosperm. II. Ultrastructural observations on cell wall formation. Aust. J. Bot.25, 599–613.
Merry, J., 1942: Studies on the embryo ofHordeum sativum. II. The growth of the embryo in culture. Bull. Torrey Bot. Club69, 360–372.
Morrison, I. N., O'Brien, T. P., 1976: Cytokinesis in the developing wheat grain: division with and without a phragmoplast. Planta130, 57–67.
Norstog, K., 1972: Early development of the barley embryo: fine structure. Amer. J. Bot.59, 123–132.
—, 1974: Nucellus during early embryogeny in barley: fine structure. Bot. Gaz.135, 97–103.
Nougarède, A., Pilet, M., 1964: Infrastructure de cellules du scutellum duTriticum vulgare Vill. au cours des premières phases de la germination. C.R. Acad. Sci. Paris258, 2641–2644.
O'Brien, T. P., McCully, M. E., 1981: The Study of Plant Structure. Melbourne, Australia: Termarcarphi Pty. Ltd.
Raghaven, V., 1966: Nutrition, growth and morphogenesis of plant embryos. Biol. Rev.41, 1–58.
Randolph, L. F., 1936: Developmental morphology of the caryopsis in maize. J. Agric. Res.53, 881–916.
Reynolds, E. S., 1963: The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J. Cell Biol.17, 208–213.
Rost, T. L., Lersten, N. R., 1970: Transfer cells inSetaria lutescens (Gramineae). Protoplasma71, 403–408.
Smart, M. G., O'Brien, T. P., 1979a: Observations on the scutellum. I. Overall development during germination in four grasses. Aust. J. Bot.27, 391–401.
— —, 1979b: Observations on the scutellum. II. Histochemistry and autofluorescence of the cell wall in mature grain and during germination of wheat, barley, oats and ryegrass. Aust. J. Bot.27, 403–411.
Souèges, R., 1924: Embryogénie des Graminées. Développement de l'embryon chez lePoa annua L. C. R. Acad. Sci. Paris178, 860–862.
Spurr, A. R., 1969: A low viscosity epoxy resin embedding medium for electron microscopy. J. Ultrastruct. Res.26, 31–43.
Swift, J. G., O'Brien, T. P., 1970: Vascularization of the scutellum of wheat. Aust. J. Bot.18, 45–53.
— —, 1971: Vascular differentiation in the wheat embryo. Aust. J. Bot.19, 63–71.
— —, 1972a: The fine structure of the wheat scutellum before germination. Aust. J. biol. Sci.25, 9–22.
— —, 1972b: The fine structure of the wheat scutellum during germination. Aust. J. biol. Sci.25, 469–486.
Zee, S.-Y., O'Brien, T. P., 1971: Aleurone transfer cells and other structural features of the spikelet of millet. Aust. J. biol. Sci.24, 391–395.