Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2017
Publication Date: 10/15/2017
Citation: Levi, A., Ling, K. 2017. USVL-380, A zucchini yellow mosaic virus resistant watermelon breeding line. HortScience. 52(10):1448-1450. https://doi:10.21273/HORTSCI12292-17.
Interpretive Summary: Zucchini yellow mosaic virus causes serious economic losses to the watermelon crop in the U.S. and throughout the world, and there is a need to develop watermelon varieties resistant to this virus. ARS scientists in Charleston, SC, developed DNA sequence markers closely linked to a gene conferring resistance to this mosaic virus in a wild type watermelon with poor fruit quality. The ARS scientists used a procedure called “marker-assisted selection” combined with conventional cross-breeding techniques to transfer zucchini yellow mosaic virus resistance into a more conventional watermelon type that is very similar to the heirloom cultivar ‘Charleston Gray’. The new mosaic virus-resistant watermelon line has been designated ‘USVL-380’, and it has the added value of desirable fruiting characteristics similar to the ‘Charleston Gray’ parent. There is significant demand for this new watermelon line by seed company breeders and others working to enhance zucchini yellow mosaic virus resistance in their elite watermelon cultivars.
Technical Abstract: We report the development of a novel watermelon line ‘USVL-380’ [Citrullus lanatus (Thunb.) Matsum. & Nakai] resistant to the zucchini yellow mosaic virus-Florida strain (ZYMV-FL). This breeding line is homozygous for the recessive eukaryotic elongation factor eIF4E allele associated with ZYMV-resistance in Plant Introduction (PI) 595203. USVL-380 was developed through a breeding process that included selection of a ZYMV-resistant F3 plant (PI 595203 x ‘New Hampshire Midget’) crossed to ‘Charleston Gray’ and advanced to BC2F7 using ‘Charleston Gray’ as recurrent parent. The breeding process involved the following stringent selection criteria: 1) phenotype rating of plants inoculated with ZYMV-FL in the greenhouse, 2) an enzyme linked immunosorbent assay (ELISA), and 3) marker assisted selection (MAS) to incorporate the eIF4E allele associated with resistance into the ‘Charleston Gray’ genome background. In field trials in Charleston, SC, (2012-2014), USVL-380 plants produced on average 1.2 mature elongated fruits per plant in mid-late season (78-82 days post planting). Mature fruits have an average length and width of 53.16 and 22.17 cm, respectively, and an average weight of 13.66 kg. The rind is light green-gray with an average thickness of 0.89”. The flesh is light red with a sweet flavor and a solid soluble content of 8.6. The USVL-380 should be useful in breeding programs aiming to enhance resistance to ZYMV-FL in watermelon cultivars.