Recessive resistance to CYSDV in melon TGR 1551

J.D. McCreight, W.M. Wintermantel, E.T. Natwick, J.W. Sinclair, K.M. Crosby, M.L. Gómez-Guillamón
Cucurbit yellow stunting disorder virus (CYSDV) reduces melon (Cucumis melo L.) fruit quality and yield in many parts of the world. Host plant resistance of melon to CYSDV is a high priority for sustainable melon production in affected production areas. High-level resistance to CYSDV exhibited by TGR 1551 (PI 482420) appeared, initially, to be controlled by a dominant gene, based on greenhouse tests in Málaga, Spain that were terminated 28 to 42 days post-inoculation (DPI). We report here results of tests that were evaluated over periods ranging from 49 DPI (Málaga) to 91 DPI (Texas) following exposure to CYSDV that show resistance to CYSDV in TGR 1551 to be a recessive trait. Mean CYSDV symptom severity rating of F1 TGR 1551 × LSQUODulceRSQUO did not significantly differ from the mean rating for TGR 1551, but the F2 distribution suggested a recessive gene for resistance to CYSDV in controlled inoculation, greenhouse tests in Texas. The F1 TGR 1551 × LSQUOBola de OroRSQUO was susceptible in a greenhouse in Málaga, where it exhibited CYSDV symptoms and was positive for CYSDV infection prior to symptom expression. TGR 1551 clearly expressed recessive genetic resistance in open field tests in Imperial Valley, California where the mean symptom severity ratings of LSQUOTop MarkRSQUO and the F1 TGR 1551 × LSQUOTop MarkRSQUO were not significantly different, and the F2 and respective testcrosses confirmed recessive resistance to CYSDV.
McCreight, J.D., Wintermantel, W.M., Natwick, E.T., Sinclair, J.W., Crosby, K.M. and Gómez-Guillamón, M.L. (2017). Recessive resistance to CYSDV in melon TGR 1551. Acta Hortic. 1151, 101-108
DOI: 10.17660/ActaHortic.2017.1151.17
Cucurbit yellow stunting disorder virus, Cucumis melo, sweet potato whitefly biotype B, sweet potato whitefly biotype Q, PI 482420

Acta Horticulturae