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Article
A Modified Method to Screen for Partial Resistance to Phytophthora sojae in Soybean
Crop Science
  • Silvina Stewart, Iowa State University
  • Alison E. Robertson, Iowa State University
Document Type
Article
Publication Version
Accepted Manuscript
Publication Date
1-1-2012
DOI
10.2135/cropsci2011.05.0241
Abstract

Phytophthora root and stem rot, caused by Phytophthora sojae Kauf and Gerd, is one of the most damaging diseases of soybean [Glycine max (L.) Merr.] in the United States. Partial resistance (PR), which is defined as the relative ability of a soybean plant to survive root infection without showing severe symptoms, is an effective way to manage this disease. A modification of the layer test method used to screen for PR to P. sojae in soybean was evaluated. Instead of the P. sojae-colonized agar layer, which is used in the current greenhouse cup assay, P. sojaeinfested rice (Oryza sativa L.) grains were used. In addition, a dry root weight (Drw) measurement was compared to a disease severity root rot score, which uses a 1 to 10 visual scale. The rice method was not statistically different from the layer test for the variables evaluated. Advantages of the rice method include reduced cost and the ability to screen soybean germplasm with more than one pathotype of the pathogen in a single assay. A mixture of several pathotypes of P. sojae ensures compatible interactions between isolates used and all known Rps genes, thus avoiding Rps genes that could go undetected and mask PR during screening. Although collecting and handling of roots for Drw data may require more time, it is a more objective variable, which assures precise scoring, it is not rater dependent, and less training of personnel is required.

Comments

This is a manuscriipt of an article published as Stewart, Silvina, and Alison E. Robertson. "A modified method to screen for partial resistance to Phytophthora sojae in soybean." Crop science 52, no. 3 (2012): 1181-1186. doi: 10.2135/cropsci2011.05.0241. Posted with permission.

Copyright Owner
Crop Science Society of America
Language
en
File Format
application/pdf
Citation Information
Silvina Stewart and Alison E. Robertson. "A Modified Method to Screen for Partial Resistance to Phytophthora sojae in Soybean" Crop Science Vol. 52 Iss. 3 (2012) p. 1181 - 1186
Available at: http://works.bepress.com/alison-robertson/268/