Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-27T07:58:11.289Z Has data issue: false hasContentIssue false
  • English
  • Français

Structure of the Covering Layers of the Wild Oat (Avena fatua) Caryopsis

Published online by Cambridge University Press:  12 June 2017

Ian N. Morrison  and
Leonard Dushnicky
Ian N. Morrison
Affiliation:
Dep. Plant Sci., Univ. of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
Leonard Dushnicky
Affiliation:
Dep. Plant Sci., Univ. of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
Get access Rights & Permissions [Opens in a new window]

Abstract

The anatomy of the husk (lemma and palea) and caryopsis coat (pericarp, seed coat or testa, and nucellar epidermis) of a typical mature wild oat (Avena fatua L.) caryopsis was investigated using both scanning electron microscopy and light microscopy. Both the lemma and palea consist of very thick-walled, lignified cells. In section, the lemma appears almost twice as thick as the palea. The pericarp is comprised of only one or two layers of relatively thin-walled cells and is closely appressed to the underlying seed coat over most of the grain. Both the outer seed-coat cuticle and the inner cuticle are present over almost the entire caryopsis and are continuous with the pigment strand that occurs deep in the crease region of the grain. The only discontinuities in the seed coat are at the basal end of the grain near the embryo. In the dorsal region of the caryopsis, the outer cuticle is approximately 3.5 μm in thickness, whereas the inner cuticle is less than 1 μm in thickness. Where the two pass over the embryo they are much thinner, with the inner cuticle becoming almost indistinguishable in places. The remains of the nucellar epidermis are tightly amalgamated to the seed coat and outer tangential walls of the underlying aleurone cells, which are clearly distinguishable by their large size and characteristic appearance.

Keywords

Seed coatpericarpanatomymicroscopy
Type
Research Article
Information
Weed Science , Volume 30 , Issue 4 , July 1982 , pp. 352 - 359
Copyright
Copyright © 1982 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

1. Banting, J. D. 1966. Studies on the persistence of Avena fatua . Can. J. Plant Sci. 46:129–140.CrossRefGoogle Scholar
2. Baum, B. R. 1971. Additional taxonomic studies on Avena fatuoids: some morphological attributes seen using the scanning electron microscope. Can. J. Bot. 49:647–649.CrossRefGoogle Scholar
3. Baum, B. R. 1977. Oats: wild and cultivated. Monograph No. 14, Biosystematics Res. Inst., Canada Dep. Agric., Ottawa. 463 pp.Google Scholar
4. Black, M. 1959. Dormancy studies in seed of Avena fatua I. The possible role of germination inhibitors. Can. J. Bot. 37:393–402.CrossRefGoogle Scholar
5. Bonnett, O. T. 1961. The oat plant: its histology and development. Bull. 672, Univ. of Illinois, Agric. Exp. Stn., Urbana. 112 pp.Google Scholar
6. Chancellor, R. J. 1976. Seed behaviour. Pages 65–87 in Price Jones, D., ed. Wild Oats in World Agriculture. Agric. Res. Council, London.Google Scholar
7. Esau, K. 1965. Plant Anatomy, 2nd ed. John Wiley and Sons, New York. 767 pp.Google Scholar
8. Feder, N. and O'Brien, T. P. 1968. Plant microtechnique: some principles and new methods. Am. J. Bot. 55:123–142.CrossRefGoogle Scholar
9. Fulcher, R. G. and Wong, S. I. 1980. Inside cereals — a fluorescence microchemical view. Pages 1–26 in Inglett, G. E. and Munck, L., eds. Cereals for Food and Beverages. Academic Press, New York.Google Scholar
10. Hart, J. W. and Berrie, A.M.M. 1966. The germination of Avena fatua under different gaseous environments. Physiol. Plantarum 19:1020–1025.CrossRefGoogle Scholar
11. Hsiao, A. I. 1979. The effect of sodium hypochlorite and gibberellic acid on seed dormancy and germination of wild oats (Avena fatua). Can. J. Bot. 57:1729–1734.CrossRefGoogle Scholar
12. Krauss, L. 1933. Entwicklungsgeschichte der Früchte von Hordeum, Triticum, Bromus und Poa mit besonderer Berücksichtigung ihrer Samenschalen. Jahrb. Wiss. Bot. 77:733–808.Google Scholar
13. Morrison, I. N. 1975. Ultrastructure of the cuticular membranes of the developing wheat grain. Can. J. Bot. 53:2077–2087.CrossRefGoogle Scholar
14. Naylor, J. M. and Fedec, P. 1978. Dormancy studies in seed of Avena fatua. 8. Genetic diversity affecting response to temperature. Can. J. Bot. 56:2224–2229.CrossRefGoogle Scholar
15. Pomeranz, Y. and Sachs, I. B. 1972. Scanning electron microscopy of the oat kernel. Cereal Chem. 49:20–22.Google Scholar
16. Richardson, S. G. 1979. Factors influencing the development of primary dormancy in wild oat seeds. Can. J. Plant Sci. 59:777–784.CrossRefGoogle Scholar
17. Rost, T. L. 1973. The anatomy of the caryopsis coat in mature caryopses of the yellow foxtail grass (Setaria lutescens). Bot. Gaz. 134:32–39.CrossRefGoogle Scholar
18. Rost, T. L. and Lersten, N. R. 1973. A synopsis and selected bibliography of grass caryopsis anatomy and fine structure. Iowa State J. Res. 48:47–87.Google Scholar
19. Sharma, M. P., McBeath, D. K., and Vanden Born, W. H. 1976. Studies on the biology of wild oats. I. Dormancy, germination and emergence. Can. J. Plant Sci. 56:611–618.CrossRefGoogle Scholar
20. Simpson, G. M. 1978. Metabolic regulation of dormancy in seeds — a case history of wild oat (Avena fatua). Pages 167–220 in Clutter, M. E., ed. Dormancy and Development Arrest. Academic Press, New York.CrossRefGoogle Scholar
21. Stinson, R. H. and Peterson, R. L. 1979. On sowing wild oats. Can. J. Bot. 57:1292–1295.CrossRefGoogle Scholar
22. True, R. H. 1893. On the development of the caryopsis. Bot. Gaz. 18:212–226.CrossRefGoogle Scholar
23. Zee, S. Y. and O'Brien, T. P. 1970. Studies on the ontogeny of the pigment strand in the caryopsis of wheat. Aust. J. Biol. Sci. 23:1153–1171.CrossRefGoogle Scholar