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ARS Home » Midwest Area » West Lafayette, Indiana » Crop Production and Pest Control Research » Research » Publications at this Location » Publication #212330
Title: Phytophthora Resistance of Soybean Germplasm with High Potential for Asian Soybean Rust Resistance

Author
item SMITH, D. - PURDUE UNIV.
item Abney, Thomas
item WESTPHAL, A - PURDUE UNIV.

Submitted to: Southern Soybean Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 1/30/2007
Publication Date: 2/19/2007
Citation: Smith, D.A., Abney, T.S., Westphal, A. 2007. Phytophthora Resistance of Soybean Germplasm with High Potential for Asian Soybean Rust Resistance [abstract]. Southern Soybean Conference Proceedings, February 18, 2007, St. Louis, Missouri. p. 6.

Interpretive Summary:

Technical Abstract: Multiple disease resistance is an important component of production agriculture. Major challenges include resistance to Phytophthora root rot caused by evolving Phytophthora sojae races and the recently introduced invasive Asian soybean rust (ASBR) caused by Phakopsora pachyrhizi. The diseases caused by these two pathogens pose a major threat to soybean production and profitability for U.S. soybean growers. This report includes data on P. sojae resistance in soybean lines evaluated for Asian soybean rust at the University of Georgia in 2005 and 2006 by R. Boerma et. al. ( http://edge.cropsoil.uga.edu/soylab/rustresistance.html ). These Phytophthora resistance data are directly applicable to breeding programs focused on maintaining resistance as it impacts sustainability. Seed of the soybean lines included in the University of Georgia rust resistance studies were obtained from the USDA Soybean Germplasm Collection (R.L. Nelson, Urbana, IL). Phytophthora resistance of soybean seedlings was identified in greenhouse studies following hypocotyl inoculations with selected P. sojae race isolates. Initial assessments of Phytophthora resistance identified 22 of the 46 soybean lines as having Phytophthora resistance based on inoculations with an Indiana isolate of P. sojae race-1 (Rps7 virulence). Soybean lines identified with Phytophthora resistance include: PI 230970*, PI 398288, PI 398399, PI 416834*, PI 417089B*, PI 437658*, PI 470227B*, PI 476905A*, PI 506965, PI 567024*, PI 567027A*, PI 567046A, PI 567058D*, PI 567085B*, PI 567129*, PI 567139B*, PI 567141*, PI 567145C, PI 605781A, PI 605830A, PI 606440A, and PI 616498. Thirteen of these lines identified with an asterisk (*) are among the 30 soybean lines identified by R. Boerma et. al. as having a field rating of less than 3.0 for ASBR in 2006. Additional information for Phytophthora resistance was also determined with Indiana isolates of race-7 (Rps1-a, 2, 3-a, 3c, 5, 6, and 7 virulence), race-25 (Rps1-a, 1-b, 1-c, 1-k, and 7 virulence), and race-17 (Rps 1-b, 1-d, 3-a, 3-b, 3-c, 4, 5, 6, and 7 virulence as previously described plus virulence to Rps 8 and 2). This additional information will be discussed and can be used by breeders and pathologists working with the soybean germplasm to more precisely identify Rps gene(s) that are involved in conferring resistance.