|Brown, Charles - Chuck|
Submitted to: American Journal of Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2006
Publication Date: 1/15/2007
Citation: Ottoman, R.J., Hane, D.C., Brown, C.R., Yilma, S., Mosley, A.R., Gutbrod, O., Vales, M. 2007. Usefulness of Molecular Markers Screening for PVY Resistance (Ryadg gene) in Potato. American Journal of Potato Research. 84: 108. Interpretive Summary:
Technical Abstract: Artificial inoculation under controlled conditions followed by ELISA is traditionally used to screen for PVY resistance. This method is very tedious, time consuming and prohibits screening of large segregating populations. The gene Ryadg from S. tuberosum ssp. andigena provides extreme resistance to PVY. This gene was mapped to chromosome XI and user-friendly PCR-based DNA markers have been developed. The objective of this work was to assess the usefulness of molecular markers linked to Ryadg as an indirect selection tool. To achieve this, a full-sib tetraploid population segregating for Ryadg was screened with molecular markers linked to Ryadg and artificially inoculated with PVY. Ninety-six percent of the segregating lines showed coincidence between molecular markers and ELISA results at 40 days after inoculations. Discrepancies in 4% of the cases could be caused by escapes from inoculation, errors in ELISA or PCR assays, recombination between the markers and the Ryadg gene and/or time of evaluation. Segregation of the ELISA and molecular marker results in the full-sib population indicated the presence of Ryadg as a simplex in the PVY resistant parent. This information was taken into account for screening two segregating populations under field conditions. From 316 clones, nine (2.8%) were selected at the single hill level based on visual tuber characteristics. Four (44.4%) contained markers associated with the PVY resistance gene Ryadg. By using MAS for PVY resistance we reduced the number of PVY susceptible lines retained for succeeding field evaluations, and thereby increased the odds of generating PVY resistant potato varieties.