Start Date: Sep 01, 2008
End Date: Aug 31, 2013
In this study, three cereal species (barley, sorghum, and wheat) will be analyzed in parallel. They will be infested with selected biotypes of greenbug or Russian wheat aphid in the controlled greenhouse environment. Following infestation, phenotypic responses of the host plants will be evaluated at various time points. Then leaf tissues of infested plants will be collected to analyze any related changes in gene expression caused by aphid infestation. DNA markers will be used to identify resistance QTLs and to localize genes for host plant resistance to the cereal aphids based on genotyping in the mapping populations. Finally we will analyze their genetic diversity in host defense and their linkage to genetically characterized resistance genes. The results from comparative genomics studies in barley, sorghum, and wheat will reveal the similarities of host resistance mechanisms and suggest possible mechanisms to generate diversity in resistance loci.