|GUNER, N - Sakata Seed America, Inc|
|OREN, E - Israel Agricultural Research Organization (ARO)|
|TADMOR, Y - Israel Agricultural Research Organization (ARO)|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2015
Publication Date: 1/15/2016
Citation: Levi, A., Coffey, J., Massey, L.M., Guner, N., Oren, E., Tadmor, Y., Ling, K. 2016. Resistance to papaya ringspot virus-watermelon strain (PRSV-W) in the desert watermelon Citrullus colocynthis. HortScience. 51:4-7.
Interpretive Summary: The watermelon crop is susceptible to a large number of diseases and pests that cause serious economic damage to growers in the U.S. and throughout the world. ARS has a set of watermelon accessions collected in the wild that are a useful source og genetic stocks for identifying and breeding disease resistance into watermelon cultivars. In this study, ARS scientists collaborated with scientists at the Agricultural Research Organization (ARO), Israel, and also a seed company cooperator on evaluating accessions of desert watermelon for papaya ringspot virus (PRSV). The scientists identified accessions collected in Egypt and the Northern Indian Desert of Rajasthan as highly resistant to PRSV. The information produced in this study should be useful for seed companies, plant breeders, and University scientists interested in identifying the genes conferring PRSV-resistance and incorporating the resistance into watermelon cultivars.
Technical Abstract: The bitter desert watermelon (Citrullus colocynthis) is a valuable source for improving disease or pest resistance in watermelon cultivars. The objective of this study was to identify C. colocynthis accessions displaying resistance to the papaya ringspot virus-watermelon strain (PRSV-W) that could be a useful source for enhancing PRSV-W in watermelon cultivars. Thirty-three accessions of C. colocynthis collected in Africa, Asia, and the Middle East were evaluated for PRSV-W-resistance. Of these 33 accessions, 4 showed high resistance to PRSV. These four resistant accessions included the U.S. Plant Introduction (PI) 525080 (collected in Qena, Egypt), PI 537277, PI 652554 and Griffin 14201 (all these three PIs were collected in the Northern Indian Desert of Rajasthan). Plants of these 4 resistant PIs were self-pollinated to produce S1 and S2 seeds and tests with S1 and S2 plants confirmed that the PRSV-resistance was inherited to all progenies. Since there is a wide genetic distance between watermelon cultivars (C. lanatus var. lanatus) and C. colocynthis, we performed crosses and backcrosses with the watermelon cultivars Charleston Gray and/or Sugar Baby and produced several viable seeds that might be useful in the development of genetic populations and in introducing the resistance into watermelon cultivars.