PMN Proeedings: 2011 Field Crops Rust Symposium

2011 Field Crops Rust Symposium:
Abstract

Poster #22

Characterization of Soybean Host Resistance and Asian Soybean Rust (ASR) Pathogen Variability for Durable Resistance

Presenting Author: P. TIAN

Coauthor: S. M. Smith

Affiliation: Dept. of Plant Pathology, University of Georgia, Athens, GA, USA

Phakopsora pachyrhizi is the causal agent of Asian soybean rust (ASR), which is one of the most aggressive soybean diseases. Resistance to ASR is controlled by five resistance genes (Rpp1-Rpp5) that have shown to be ineffective when challenged with different isolates of P. pachyrhizi. A better understanding of the genetics of resistance to ASR is needed to assist in the rapid and efficient development of new resistant varieties. Therefore, knowledge of the genetics of resistance to ASR and the variability of ASR populations is essential in dissecting the relationship between the host and pathogen and in developing effective breeding strategies for resistance. This project has three major research components: 1) characterization of host resistance; 2) analysis of pathogen variability; and 3) integration of host and pathogen datasets to establish pipelines for release of resistance cultivars. We propose to characterize current ASR Georgia field isolates; characterize resistance phenotypes of released cultivars grown in Georgia in response to inoculation with ASR Georgia field isolates; identify candidate effector genes in ASR isolates; and characterize specific resistance genes that can be used to develop durable broad-spectrum disease resistance strategies for soybean cultivars grown in Georgia. By integration of the host and pathogen datasets, this work will establish pipelines for the release of resistant genotypes to diversify selection pressure on pathogens and increase the evolutionary barrier required for the pathogens to overcome resistance, thereby increasing the durability of resistance.