title: Pathogenic diversity of Phytophthora sojae and breeding strategies to develop Phytophthora-resistant soybeans.
abstract: Phytophthora stem and root rot, caused by Phytophthora sojae, is one of the most destructive diseases of soybean [Glycine max (L.) Merr.], and the incidence of this disease has been increasing in several soybean-producing areas around the world. This presents serious limitations for soybean production, with yield losses from 4 to 100%. The most effective method to reduce damage would be to grow Phytophthora-resistant soybean cultivars, and two types of host resistance have been described. Race-specific resistance conditioned by single dominant Rps ("resistance to Phytophthora sojae") genes and quantitatively inherited partial resistance conferred by multiple genes could both provide protection from the pathogen. Molecular markers linked to Rps genes or quantitative trait loci (QTLs) underlying partial resistance have been identified on several molecular linkage groups corresponding to chromosomes. These markers can be used to screen for Phytophthora-resistant plants rapidly and efficiently, and to combine multiple resistance genes in the same background. This paper reviews what is currently known about pathogenic races of P. sojae in the USA and Japan, selection of sources of Rps genes or minor genes providing partial resistance, and the current state and future scope of breeding Phytophthora-resistant soybean cultivars.
authors.affiliation: Hyogo Agricultural Institute for Agriculture, Forestry and Fisheries , 1533 Minamino-oka, Kasai, Hyogo 679-0198, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Sugimoto
authors.forename: Masayasu
authors.initials: M
authors.lastname: Kato
authors.forename: Shinya
authors.initials: S
authors.lastname: Yoshida
authors.forename: Isao
authors.initials: I
authors.lastname: Matsumoto
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Akito
authors.initials: A
authors.lastname: Kaga
authors.forename: Makita
authors.initials: M
authors.lastname: Hajika
authors.forename: Ryo
authors.initials: R
authors.lastname: Yamamoto
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Watanabe
authors.forename: Masataka
authors.initials: M
authors.lastname: Aino
authors.forename: Toru
authors.initials: T
authors.lastname: Matoh
authors.forename: David R
authors.initials: DR
authors.lastname: Walker
authors.forename: Alan R
authors.initials: AR
authors.lastname: Biggs
authors.forename: Masao
authors.initials: M
authors.lastname: Ishimoto
keywords: Phytophthora sojae; Phytophthora stem and root rot; Rps gene; partial resistance; race-specific resistance; soybean