title: Molecular mapping of soybean rust (Phakopsora pachyrhizi) resistance genes: discovery of a novel locus and alleles.
abstract: Soybean production in South and North America has recently been threatened by the widespread dissemination of soybean rust (SBR) caused by the fungus Phakopsora pachyrhizi. Currently, chemical spray containing fungicides is the only effective method to control the disease. This strategy increases production costs and exposes the environment to higher levels of fungicides. As a first step towards the development of SBR resistant cultivars, we studied the genetic basis of SBR resistance in five F2 populations derived from crossing the Brazilian-adapted susceptible cultivar CD 208 to each of five different plant introductions (PI 200487, PI 200526, PI 230970, PI 459025, PI 471904) carrying SBR-resistant genes (Rpp). Molecular mapping of SBR-resistance genes was performed in three of these PIs (PI 459025, PI 200526, PI 471904), and also in two other PIs (PI 200456 and 224270). The strategy mapped two genes present in PI 230970 and PI 459025, the original sources of Rpp2 and Rpp4, to linkage groups (LG) J and G, respectively. A new SBR resistance locus, rpp5 was mapped in the LG-N. Together, the genetic and molecular analysis suggested multiple alleles or closely linked genes that govern SBR resistance in soybean.
authors.affiliation: State University of Londrina (UEL), Rod. Celso Garcia Cid Km 380, Cx. Postal 6001, CEP 86051-990 Londrina, PR, Brazil.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Garcia
authors.forename: Eberson Sanches
authors.initials: ES
authors.lastname: Calvo
authors.forename: Romeu Afonso
authors.initials: RA
authors.lastname: de Souza Kiihl
authors.forename: Arlindo
authors.initials: A
authors.lastname: Harada
authors.forename: Dario Minoru
authors.initials: DM
authors.lastname: Hiromoto
authors.forename: Luiz Gonzaga Esteves
authors.initials: LG
authors.lastname: Vieira
mesh_terms: D000483:Alleles; D001487:Basidiomycota / Q000472:pathogenicity*; D002874:Chromosome Mapping; D017343:Genes, Plant; D006824:Hybridization, Genetic; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology*; D013025:Glycine max / Q000235:genetics* / Q000382:microbiology*