2011 Field Crops Rust Symposium:
Management of the Switchgrass Rust Disease by Deploying Host Resistant Genes and Monitoring the Dynamics of Pathogen Populations
Presenting Author: B. ZHAO (1)
Coauthors: S. M. Marek (2), C. D. Garzon (2), B. Tyler (3), B. Yang (4)
Affiliations: (1) Dept. of Horticulture, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; (2) Dept. of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK, USA; (3) Virginia Bioinformatics Institute, Blacksburg, VA, USA; (4) Dept. of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
Switchgrass is considered a prime candidate for large-scale biomass production for lignocellulose-derived bioenergy. Sustainable switchgrass biomass production could be negatively impacted by the epidemics of rust disease caused by Puccinia emaculata Schwein. Deployment of host resistance genes guided by rust population genetics information is the best practice to durably and sustainably protect switchgrass feedstock production against rust infection. We have made a large collection switchgrass germplasm and established a reproducible switchgrass rust pathosystem. Evaluating our germplasm for rust resistance has led us to identify potential rust resistance genes from switchgrass cultivar Alamo. A potential virus-induced gene silencing tool for quickly analyzing the function of rust resistance genes has been developed. As a complement to natural resistance genes, a novel strategy has been developed that has great potential to generate broad-spectrum rust disease resistance. We will present our preliminary results on 1) genetic identification of switchgrass rust resistance gene(s) and associate the resistance genes with molecular markers; 2) developing a novel virus-induced gene silencing system for functional analysis of putative rust resistance genes in switchgrass; 3) engineering switchgrass with broad-spectrum disease resistance; and 4) collection of rust isolates across the country and determination of the structure of switchgrass rust populations. Our expected outcome of this project would allow the breeding of broad-spectrum rust-resistant switchgrass cultivars that could be strategically deployed according to the local rust pathogen population to ensure the large-scale and sustainable biomass production in the future.