Campus Units

Plant Pathology and Microbiology

Document Type

Article

Publication Version

Published Version

Publication Date

7-2016

Journal or Book Title

Plant Disease

Volume

100

Issue

7

First Page

1429

Last Page

1437

DOI

10.1094/PDIS-08-15-0879-RE

Abstract

Pathotype diversity of Phytophthora sojae was assessed in 11 states in the United States during 2012 and 2013. Isolates of P. sojae were recovered from 202 fields, either from soil samples using a soybean seedling bioassay or by isolation from symptomatic plants. Each isolate was inoculated directly onto 12 soybean differentials; no Rps gene or Rps 1a, 1b, 1c, 1k, 3a, 3b, 3c, 4, 6, 7, or 8. There were 213 unique virulence pathotypes identified among the 873 isolates collected. None of the Rps genes were effective against all the isolates collected but Rps6 and Rps8 were effective against the majority of isolates collected in the northern regions of the sampled area. Virulence toward Rps1a, 1b, 1c, and 1k ranged from 36 to 100% of isolates collected in each state, while virulence to Rps6 and Rps8 was less than 36 and 10%, respectively. Depending on the state, the effectiveness of Rps3a ranged from totally effective to susceptible to more than 40% of the isolates. Pathotype complexity has increased in populations of P. sojae in the United States, emphasizing the increasing importance of stacked Rps genes in combination with high partial resistance as a means of limiting losses to P. sojae.

Comments

This article is published as Dorrance, A. E., J. Kurle, A. E. Robertson, C. A. Bradley, L. Giesler, K. Wise, and V. C. Concibido. "Pathotype diversity of Phytophthora sojae in eleven states in the United States." Plant Disease 100, no. 7 (2016): 1429-1437. doi: 10.1094/PDIS-08-15-0879-RE. Posted with permission.

Copyright Owner

The American Phytopathological Society

Language

en

File Format

application/pdf

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