Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-24T09:00:12.620Z Has data issue: false hasContentIssue false

Regulation of Witchweed (Striga asiatica) Conditioning and Germination by dl-Strigol

Published online by Cambridge University Press:  12 June 2017

A. I. Hsiao
Affiliation:
Agric. Can. Res. Stn., Box 440, Regina, SK, Canada S4P 3A2
A. D. Worsham
Affiliation:
Crop Sci. Dep.
D. E. Moreland
Affiliation:
Agric. Res., Sci. Ed. Admin., U.S. Dep. Agric., North Carolina State Univ., Raleigh, NC 27650

Abstract

The conditioning and germination processes of witchweed [Striga asiatica (L.) Kuntze] seeds were regulated by synthetic dl-strigol (ST) or natural stimulants (STM) present in a corn (Zea mays L.) root-exudate solution. Seeds conditioned in water for 7 and 14 days required 10−10 and 10−12M ST, respectively, to induce maximum germination (ca. 80%). Surprisingly, conditioning seeds in ST or STM had an adverse effect on the responsiveness of the seeds to the same compounds after conditioning. Compared to seeds conditioned in water, these ST- or STM-conditioned seeds required not only higher concentrations of ST or STM to induce maximum germination, but also longer immersion time to become conditioned. ST or STM inhibits conditioning and thus the regulation of germination by ST or STM depends mainly on the stage of conditioning of seeds when they are exposed to ST or STM. ST or STM stimulates germination only after a pre-germination threshold is reached during conditioning. Exposure of seeds to ST or STM before this critical level is reached apparently inhibits conditioning.

Type
Research Article
Copyright
Copyright © 1981 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. Brown, R. and Edwards, M. 1946. The germination of the seed of Striga lutea. II. The effect of time of treatment and of concentration of the host stimulant. Ann. Bot (London). 10:134142.Google Scholar
2. Cook, C. E., Whichard, L. P., Turner, B., Wall, M. E., and Egley, G. H. 1966. Germination of witchweed (Striga lutea Lour.): Isolation and properties of a potent stimulant. Science 154:11891190.CrossRefGoogle ScholarPubMed
3. Cook, C. E., Whichard, L. P., Wall, M. E., Egley, G. H., Coggon, P., Luhan, P. A., and McPhail, A. T. 1972. Germination stimulants. II. The structure of strigol – A potent seed germination stimulant for witchweed (Striga lutea Lour.). J. Am. Chem. Soc. 94:61986199.CrossRefGoogle Scholar
4. Egley, G. H. 1972. Influence of the seed envelope and growth regulators upon seed dormancy in witchweed (Striga lutea Lour.). Ann. Bot. (London). 36:755770.CrossRefGoogle Scholar
5. Heather, J. B., Mittal, R. S. D., and Sih, C. J. 1974. The total synthesis of dl-strigol. J. Am. Chem. Soc. 96:19761977.Google Scholar
6. Hsiao, A. I., Worsham, A. D., and Moreland, D. E. 1979. Factors affecting conditioning and germination of witchweed (Striga asiatica (L.) Kuntze) seeds under laboratory conditions. Pages 193201 in Musselman, L. J., Worsham, A. D., and Eplee, R. E., eds. Proc. 2nd Symp. on Parasitic Weeds, North Carolina State Univ., Raleigh, NC.Google Scholar
7. Johnson, A. W., Roseberry, G., and Parker, C. 1976. A novel approach to Striga and Orobanche control using synthetic germination stimulants. Weed Res. 16:223227.Google Scholar
8. Kust, C. A. 1966. A germination inhibitor in Striga seed. Weed Sci. 14:327329.Google Scholar
9. Nelson, R. R. 1958. Preliminary studies on the host range of Striga asiatica . Plant Dis. Rep. 42:376382.Google Scholar
10. Vallance, K. B. 1951. Studies on the germination of the seeds of Striga hermonthica. II. The effect of the stimulating solution on seed respiration. J. Exp. Bot. 2:3140.Google Scholar
11. Worsham, A. D., Moreland, D. E., and Klingman, G. C. 1959. Stimulation of Striga asiatica (witchweed) seed germination by 6-substituted purines. Science 130:16541656.CrossRefGoogle Scholar