American Potato Journal

, Volume 32, Issue 5, pp 180–188 | Cite as

Some new findings concerningPhytophthora infestans (Mont.) De By

  • J. L. Howatt
  • P. N. Grainger


This paper records the findings of experimental work conducted during the past six months on various phases of investigation relative to the development and behavior ofP. infestans (Mont.) De By.

The present paper confirms the existence of race (1,2,3,4).

Improvements in the blight testing technique and apparatus are described.

Information relative to the behavior of the fungus under definite environmental conditions has established some obscure host-parasite relationships of the organism.

Evidence is presented to show that certain differential hosts proposed in the International System, possibly, are not genotypic equivalents. The difficulties of designating races by this System are indicated.

The erratic behavior of monozoosporous isolates is attributed to discriminatory faults in the differential series rather than to heterogeneity in the isolates.

The results of testing some parental materials and hybrids with race (1,2,3,4) are presented.


AMERICAN Potato Journal Phytophthora INFESTANS Late Blight Resistance Differential Host Differential Series 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Literature Cited

  1. 1.
    Black, W., C. Mastenbroek, W. R. Mills, and L. C. Peterson. 1953. A proposal for an international nomenclature of races ofPhytophthora infestans and of genes controlling immunity inSolanum demissum derivatives. Euphytica 2: 173–178.CrossRefGoogle Scholar
  2. 2.
    DeBruyn, H. L. G. 1926. The overwintering ofPhytophthora infestans (Mont.) De By. Phytopath. 16: 121–140.Google Scholar
  3. 3.
    — 1951. Pathogenic differentiation inPhytophthora infestans (Mont.) De By. Phytopath. Z. 18: 339–359. Cited in R.A.M. 32: 206–207, 1953.Google Scholar
  4. 4.
    Howatt, J. L. and W. A. Hodgson. 1954. Testing for late blight resistance in the potato in Canada. Amer. Potato Jour. 31: 129–140.CrossRefGoogle Scholar
  5. 5.
    Wallin, J. R. 1953. The production and survival of sporangia ofPhytophthora infestans on tomato and potato plants in the field. Phytopath. 43: 503–508.Google Scholar

Copyright information

© Springer 1955

Authors and Affiliations

  • J. L. Howatt
    • 1
  • P. N. Grainger
    • 1
  1. 1.Science Service, Canada Department of AgriculturePlant Pathology LaboratoryFredericton

Personalised recommendations