Authors: Danielle C G Silva Naoki Yamanaka Rodrigo L Brogin Carlos A A Arias Alexandre L Nepomuceno Antônio O Di Mauro Selma S Pereira Livia M Nogueira André L L Passianotto Ricardo V Abdelnoor
Publish Date: 2008/04/08
Volume: 117, Issue: 1, Pages: 57-63
Abstract
Asian soybean rust ASR is caused by the fungal pathogen Phakopsora pachyrhizi Sydow Sydow It was first identified in Brazil in 2001 and quickly infected soybean areas in several countries in South America Primary efforts to combat this disease must involve the development of resistant cultivars Four distinct genes that confer resistance against ASR have been reported Rpp1 Rpp2 Rpp3 and Rpp4 However no cultivar carrying any of those resistance loci has been released The main objective of this study was to genetically map Rpp2 and Rpp4 resistance genes Two F23 populations derived from the crosses between the resistant lines PI 230970 Rpp2 PI 459025 Rpp4 and the susceptible cultivar BRS 184 were used in this study The mapping populations and parental lines were inoculated with a field isolate of P pachyrhizi and evaluated for lesion type as resistant RB lesions or susceptible TAN lesions The mapping populations were screened with SSR markers using the bulk segregant analysis BSA to expedite the identification of linked markers Both resistance genes showed an expected segregation ratio for a dominant trait This study allowed mapping Rpp2 and Rpp4 loci on the linkage groups J and G respectively The associated markers will be of great value on marker assisted selection for this traitThis study was partly supported by Japan International Research Center for Agricultural Sciences JIRCAS international project Identification of Stable Resistance to Soybean Rust for South America National Council for Scientific and Technological Development CNPq and Studies and Projects Financing Entity FINEP Approved for publication by the editorial board of Embrapa Soybean as manuscript 12/2007
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