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Experiments in selecting for resistance to downy mildew in sugar beet

Published online by Cambridge University Press:  27 March 2009

G. E. Russell
Affiliation:
Plant Breeding Institute, Trumpington, Cambridge

Summary

In tests with seedlings in the glasshouse, significant differences in susceptibility to downy mildew, caused by Peronospora farinosa f. sp. betae, were observed between individual stocks of sugar beet. The resistance of a particular stock in glasshouse tests was not always a reliable guide to its resistance in the field. There were also serious discrepancies between the results of tests with seedlings and those with mature plants in the field, suggesting that the resistance of certain stocks, relative to one another, may vary with increasing age of the host plant. This contention was supported by evidence from a field experiment in which the susceptibility of several sugar-beet stocks was compared throughout the growing season. It also appears that changes in environmental conditions affected resistance to downy mildew more in some stocks than in others.

Progenies of selected plants that had not shown severe symptoms of downy mildew, after exposure to natural inoculation with P. farinosafor more than 3 months in the field, were much more resistant than the parent stocks. This showed that a single generation of selection under suitable conditions can significantly improve the resistance of sugar-beet breeding stocks to downy mildew.

An inbred sugar-beet line of American origin showed exceptional resistance to downy mildew in experiments under glass and in the field. Inoculated plants of this line usually showed no symptoms of the disease and P. farinosa did not produce conidia on them. These results show that sources of extreme resistance are present in cultivated sugar beet and suggest that an excellent control of downy mildew in Britain may eventually be achieved through the use of resistant varieties.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1968

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References

REFERENCES

Byford, W. J. (1965). Rep. Rothamsted exp. Stn 1964, p. 261.Google Scholar
Byford, W. J. (1967a). Host specialization of Perono-spora farinosa on Beta, Spinacea and Chenopodium. Trans. Br. mycol. Soc. 50, 603–7.CrossRefGoogle Scholar
Byford, W. J. (1967b). Field experiments on sugar-beet downy mildew (Peronosporafarinosa). Ann. appl. Biol. 60, 97107.Google Scholar
Byford, W. J. (1968). Laboratory experiments on sugar-beet downy mildew (Peronospora farinosa). Ann. appl. Biol. 61, 4755.CrossRefGoogle Scholar
Byford, W. J. & Hull, R. (1967). Some observations on the economic importance of sugar-beet downy mildew in England. Ann. appl. Biol. 60, 281–96.CrossRefGoogle Scholar
Byford, W. J. & Willey, L. A. (1968). Field trials of the reaction of sugar-beet varieties to downy mildew. (In preparation.)Google Scholar
McFarlane, J. S. (1952). Breeding for resistance to downy mildew in sugar beets. Proc. Am. Soc. Sug.Beet Technol. 1952, pp. 415–20.Google Scholar
Russell, G. E. (1966). Some effects of inoculation with yellowing viruses on the susceptibility of sugar beet t o fungal pathogens. I. Susceptibility to Peronospora farinosa. Trans. Br. mycol. Soc. 49, 611–19.CrossRefGoogle Scholar
Willey, L. A. (1968). Trials of commercial varieties of sugar beet. Br. Sug. Beet Rev. 36, 163–8.Google Scholar