GENETICS AND GENETIC IMPROVEMENT OF DISEASE RESISTANCE AND QUALITY TRAITS IN WATERMELON, BROCCOLI, AND LEAFY GREEN BRASSICAS
Location: Vegetable Research
Title: Notice of Release of USVL-230, A Novel Watermelon Breeding Line
Submitted to: USDA, Agricultural Research Service, Cultivar Release
Publication Type: Germplasm Release
Publication Acceptance Date: November 9, 2009
Publication Date: November 10, 2009
Citation: Levi, A. 2009. Notice of Release of USVL-230, A Novel Watermelon Breeding Line. USDA, Agricultural Research Service, Cultivar Release. 10 November 2009.
A novel watermelon breeding line USVL-230 was developed at the USDA, ARS, US Vegetable Laboratory, Charleston, SC. The breeding line contains the nuclear genome of cultivated watermelon (Citrullus lanatus var. lanatus) and chloroplast and mitochondrial genomic background derived from the desert species C. colocynthis. USVL-230 was produced by first crossing an F1 hybrid [‘New Hampshire Midget’ (C. lanatus var. lanatus) x Griffin 14113 (C. lanatus var. citroides)] with C. colocynthis PI 386015 as the female parent. Then, most of the nuclear genes of the hybrid plant were replaced with nuclear genes of cultivated watermelon (C. lanatus var. lanatus) through a series of successive backcrosses with watermelon cultivars that were used as the male (pollinator) parents. The watermelon cultivars that were used in six successive backcrosses were: 1) ‘Allsweet’, 2) ‘Allsweet’, 3) ‘Allsweet’, 4) ‘Charleston Gray’, 5) ‘Charleston Gray’, and 6) ‘Extra Early Sugar Baby’. Then, a BC6-S1 plant was self-pollinated and selected in nine successive generations to produce USVL-230 seeds (BC6-S10). USVL-230 is a Mickylee-type watermelon with round shape fruits (8.5” long and 7.2” width), light green dappled rind (0.7-0.8”), and bright red flesh color with a pleasant flavor, and 8.1-8.7% solid soluble content. The flesh is firm but with slightly crispy texture, and does not exhibit hollow heart. During 4 years of field trials (2005-2008) in Charleston, South Carolina, USVL-230 produced 2.7 fruits per plant (9.4 lb per fruit). Fruits are ready for harvest in mid season (76 days post planting). The fruit contains brown seeds (7.0 mm long and 4.0 mm width). USVL-230 may be useful in breeding programs to enhance certain fruit characteristics, including rind color (light green dappled) and rind thickness (0.7-0.8”), flesh color (bright red) and firm texture, and flesh devoid of hollow heart. USVL-230 may also be useful in enhancing watermelon cultivars with chloroplast and mitochondrial genes derived from C. colocynthis, and in studying the effects of foreign cytoplasm (chloroplast and mitochondria) on photosynthesis, respiration, disease or pest resistance, flower production, or fruit yield and quality in cultivated watermelon.