Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-23T04:11:18.505Z Has data issue: false hasContentIssue false
  • English
  • Français

Effect of Soluble Sugars and Gibberellic Acid in Breaking Dormancy of Excised Wild Oat (Avena fatua) Embryos

Published online by Cambridge University Press:  12 June 2017

Michael E. Foley
Michael E. Foley*
Affiliation:
Dep. Bot. and Plant Pathol., Purdue Univ., West Lafayette, IN 47907
Get access Rights & Permissions [Opens in a new window]

Abstract

Dormant line M73 wild oat caryopses were utilized to develop a system for the culture of excised embryos, to evaluate whether embryo dormancy exists, and to investigate the physiological basis for breaking dormancy. Dormant embryos cultured on N6 medium solidified with 0.25% Bacto agar displayed 70% germination in 2 d compared with approximately 20% for the other gelling agents. The non-plant-based gelling agent gellum at a concentration of 0.25% was selected for further experiments on breaking dormancy after it was determined that concentrations ≥ 0.5% decreased the rate of germination. Amending N6 medium with concentrations of 0.1 to 10 μM gibberellic acid (GA) increased the rate and extent of germination. Embryos treated with 0 to 0.01 μM GA required 6 d to attain 90% germination. Germination of dormant embryos on N6 medium without GA suggested that either true embryo dormancy did not exist in M73 or some constituent of the N6 medium promoted breaking of dormancy. Subsequent experiments indicated that the 88 mM sucrose was the constituent in the N6 medium responsible for breaking dormancy. Concentrations of sucrose from 40 to 200 mM were effective in breaking dormancy. Ten μM GA increased the rate and extent of germination of embryos cultured with 88 to 200 mM sucrose. At 88 mM, fructose, maltose, glucose, and sucrose all broke embryo dormancy. Fructose was the most active soluble sugar for breaking embryo dormancy, promoting nearly 100% germination in 4 d. As with sucrose, there was an interaction between GA and the soluble sugars in breaking dormancy. Ten μM GA with 88 mM fructose provided nearly 100% germination in 1 d. Amylose, but not amylopectin or pullulan, may substitute for soluble sugars. However, with 10 μM GA amylose, amylopectin and pullulan were equally effective in breaking dormancy. Breaking dormancy of embryos on N6 medium was independent of temperatures from 12 to 24 C in the presence of GA, but in its absence the optimum was 12 C. Application of GA to dormant caryopses significantly increased and decreased the level of glucose and sucrose, respectively, in the embryo. Gibberellic acid had a similar effect on glucose and sucrose in the endosperm tissue, except the differences were not significant at all times after treatment. The change in carbohydrate metabolism, especially in embryo tissue, may be important when considered in context with the observation that soluble sugars and GA act independently in breaking dormancy in excised M73 embryos. Breaking wild oat embryo dormancy with GA may be mainly a substitution for sugar requirement.

Keywords

Wild oatAvena fatua L. #3 AVEFACarbohydratesdevelopmental arrestseed germinationstarchtissue cultureAVEFA
Type
Weed Biology and Ecology
Information
Weed Science , Volume 40 , Issue 2 , June 1992 , pp. 208 - 214
Copyright
Copyright © 1992 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. Adkins, S. W., Loewen, M., and Symons, S. J. 1986. Variation within pure lines of wild oats (Avena fatua) in relation to degree of primary dormancy. Weed Sci. 34:859–864.Google Scholar
2. Adkins, S. W. and Simpson, G. M. 1988. The physiological basis of seed dormancy in Avena fatua. IX. Characterization of two dormancy states. Physiol. Plant. 73:15–20.CrossRefGoogle Scholar
3. Andrews, C. J. and Simpson, G. M. 1969. Dormancy studies in seed of Avena fatua. 6. Germinability of the immature caryopsis. Can. J. Bot. 47:1841–1849.CrossRefGoogle Scholar
4. Atwood, W. M. 1914. A physiological study of the germination of Avena fatua . Bot. Gaz. 57:386–414.Google Scholar
5. Bewley, J. D. and Black, M. 1982. Physiology and biochemistry of seeds in relation to germination—Viability, dormancy and environmental control. Springer-Verlag, New York. 375 pp.CrossRefGoogle Scholar
6. Chih-Ching, C., Ching-Chu, W., Ching-San, S., Chen, H., Kwang-Chu, Y., Chih-Yin, C., and Feng-Yun, B. 1975. Establishment of an efficient medium for anther culture of rice through comparative experiments on the nitrogen sources. Scientia Sinica 18:659–668.Google Scholar
7. Foley, M. E. 1986. Effect of fusicoccin and gibberellic acid on primary dormant Avena fatua caryopses. Physiol. Plant. 67:690–694.Google Scholar
8. Keng, J. and Foley, M. E. 1987. Effect of gibberellin on protein and non-structural carbohydrate in dormant Avena fatua caryopses. Plant Sci. 51:37–41.CrossRefGoogle Scholar
9. MacGregor, A. W. 1987. α-amylase, limited dextrinase, and α-glucosidase enzymes in barley and malt. CRC Crit. Rev. Biotechnol. 5:117–128.CrossRefGoogle ScholarPubMed
10. Metzger, J. D. 1983. Role of endogenous plant growth regulators in seed dormancy of Avena fatua. II. Gibberellins. Plant Physiol. 73:791–795.CrossRefGoogle ScholarPubMed
11. Naylor, J. M. and Simpson, G. M. 1961. Dormancy studies in seed of Avena fatua. 2. A gibberellin-sensitive inhibitory mechanism in the embryo. Can. J. Bot. 39:281–295.CrossRefGoogle Scholar
12. Sawhney, R. 1989. Temperature control of dormancy and germination in embryos isolated from seeds of dormant and nondormant lines of wild oats (Avena fatua). Can. J. Bot. 67:128–134.CrossRefGoogle Scholar
13. Simpson, G. M. 1965. Dormancy study in seed of Avena fatua. 4. The role of gibberellin in embryo dormancy. Can. J. Bot. 43:793–816.CrossRefGoogle Scholar
14. Simpson, G. M. and Naylor, J. M. 1962. Dormancy studies in seed of Avena fatua. 3. A relationship between maltase, amylases, and gibberellin. Can. J. Bot. 40:1659–1673.Google Scholar
15. Yamada, J. 1981. Purification of oat debranching enzyme and occurrence of inactive debranching enzyme in cereals. Agric. Biol. Chem. 45:1013–1015.CrossRefGoogle Scholar