|McCreight, James - Jim|
|Wintermantel, William - Bill|
|NATWICK, ERIC - University Of California - Cooperative Extension Service|
|SINCLAIR, JONATHAN - Texas A&M University|
|CROSBY, KEVIN - Texas A&M University|
|GOMEZ-GUILLAMON, MARIA - Consejo Superior De Investigaciones Cientificas (CSIC)|
Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: 11/24/2015
Publication Date: 5/1/2017
Citation: McCreight, J.D., Wintermantel, W.M., Natwick, E.T., Sinclair, J.W., Crosby, K.M., Gomez-Guillamon, M.L. 2017. Recessive resistance to Cucurbit yellow stunting disorder virus in melon TGR 1551. Acta Horticulturae. 1151:101–107.
Interpretive Summary: Cucurbit yellow stunting disorder virus (CYSDV) reduces muskmelon and honeydew melon fruit quality and yield in many parts of the world. The virus is transmitted by the sweetpotato whitefly. Host plant resistance of melon to CYSDV and sweetpotato whitefly are high priorities for sustainable melon production in affected production areas. High-level resistance to CYSDV exhibited by the vegetable (non-sweet) melon TGR 1551 appeared, initially, to be controlled by a dominant gene, based on greenhouse tests in Málaga, Spain that were terminated 4 to 6 weeks post-inoculation. We report here that genetic resistance to CYSDV in TGR 1551 is a recessive trait based on longer duration tests in Spain, Texas and California. Recessive control of resistance to CYSDV complicates development of melon varieties resistant to CYSDV, as both parents must have the gene for resistance to the virus. This is more difficult to achieve because the gene must be transferred from vegetable type melons to sweet (dessert) types melons, and thus, will take more time to develop varieties resistant to Cucurbit yellow stunting disorder virus.
Technical Abstract: 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 4 to 6 weeks post-inoculation. We report here results of tests that were evaluated over periods ranging from 7 (Málaga) to 13 (Texas) weeks 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 x Dulce 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. TGR 1551 clearly expressed recessive genetic resistance in open field tests in Imperial Valley, California where the mean symptom severity ratings of ‘Top Mark’ and the F1 TGR 1551 x Top Mark were not significantly different, and the F2 and respective testcrosses confirmed recessive resistance to CYSDV. The F1 TGR 1551 x Bola de Oro was susceptible in a greenhouse in Málaga, where it exhibited CYSDV symptoms and was positive for CYSDV infection prior to symptom expression.