P0435 Genetic Mapping of Novel Soybean Rps Genes for Phytophthora Resistance

Feng Lin , Purdue University, West lafayette, IN
Jianxin Ma , Purdue University, West Lafayette, IN
Phytophthora root rot (PRR), caused by P. sojae, is a widespread soybean disease which results in an annual yield loss of $1~2 billion worldwide. This disease can take place on all part of soybean plants and at all stages of soybean development, especially in soils that are poorly drained or that receive excessive irrigation. To control the disease, breeders primarily employ race-specific resistant genes (named Rps genes) that have been identified to be located at 8 loci with 14 dominant alleles. However, soybean breeders are continuously facing big challenges due to the scarcity of excellent resistant genes and lack of efficient molecular markers for Marker Assisted Selection (MAS). Recently pathologists have identified two germplasms (PI567139B and PI567141) introduced from Indonesia that confer excellent resistance to all major P.sojae races in Indiana soybean field and could provide potentially new resources of Rps genes and our goal is trying to explore if new resources of Rps genes would be identified and characterized. Objectives:  Dissect the inheritance pattern of the resistance genes.; Map the new genes to soybean genome. ; Develop molecular markers for MAS. Summary Two independantly inherited resistant genes have been identified and mapped to soybean Linkage Group N and J, respectively. Further analysis suggests that both of them are novel resource of Rps genes.