Characterization of Potato Leafroll Virus Resistance Derived from Solanum Etuberosum
Potato leafroll virus (PLRV) is a primary pathogen of potato. PLRV-infected seed results in stunted and weak plants having dramatic reductions in tuber yield and quality. Plants infected with PLRV during the growing season can produce tubers displaying tuber net necrosis, ranging from a slight reduction in crop value to complete loss due to unacceptable processing quality. Control of tuber net necrosis in commercial production and PLRV infection of seed tubers requires intensive use of insecticides to control aphids that vector PLRV, due to PLRV susceptibility of the most widely grown potato varieties. Field resistance to PLRV from Solanum etuberosum has been mapped to a single gene, Rlretb, on potato chromosome 4. This research proposes to begin characterize the chromosome region surrounding Rlretb. Application of aphid and graft inoculations
to fourth generation progenies will help elucidate the mechanisms of resistance to PLRV with respect to virus multiplication, accumulation, and movement. Molecular markers closely linked to Rlretb will be analyzed with the compiled PLRV resistance mechanism data to define how this natural host resistance gene functions in the field. Incorporation of Rlretb into commercially-acceptable varieties would reduce insecticide applications, promoting more sustainable production with reduced costs for potato growers. Results will also provide insight into S. etuberosum genome structure and organization relative to S. tuberosum and S. phureja, and potentially identify a PLRV resistance gene useful for the development of intragenic/cisgenic potatoes.