Branham, S., USDA, ARS, US Vegetable Laboratory, 2700 Savannah, Highway, Charleston, SC, United States
Vexler, L., Plant Science Institute, Agricultural Research Organization, Newe Ya’ar Research Center, P.O. Box 1021, Ramat Yishay, Israel, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
Meir, A., Plant Science Institute, Agricultural Research Organization, Newe Ya’ar Research Center, P.O. Box 1021, Ramat Yishay, Israel
Tzuri, G., Plant Science Institute, Agricultural Research Organization, Newe Ya’ar Research Center, P.O. Box 1021, Ramat Yishay, Israel
Frieman, Z., Plant Science Institute, Agricultural Research Organization, Newe Ya’ar Research Center, P.O. Box 1021, Ramat Yishay, Israel
Levi, A., USDA, ARS, US Vegetable Laboratory, 2700 Savannah, Highway, Charleston, SC, United States
Wechter, W.P., USDA, ARS, US Vegetable Laboratory, 2700 Savannah, Highway, Charleston, SC, United States
Tadmor, Y., Plant Science Institute, Agricultural Research Organization, Newe Ya’ar Research Center, P.O. Box 1021, Ramat Yishay, Israel
Gur, A., Plant Science Institute, Agricultural Research Organization, Newe Ya’ar Research Center, P.O. Box 1021, Ramat Yishay, Israel

The common flesh color of commercially grown watermelon is red due to the accumulation of lycopene. However, natural variation in carotenoid composition that exists among heirloom and exotic accessions results in a wide spectrum of flesh colors. We previously identified a unique orange flesh watermelon accession (NY0016) that accumulates mainly β-carotene and no lycopene. We hypothesized this unique accession could serve as a viable source for increasing provitamin A content in watermelon. Here we characterize the mode of inheritance and genetic architecture of this trait. Analysis of testcrosses of NY0016 with yellow and red fruited lines indicated a codominant mode of action as F1 fruits exhibited a combination of carotenoid profiles from both parents. We combined visual color phenotyping with genotyping-by-sequencing of an F2:3 population from a cross of NY0016 by a yellow fruited line, to map a major locus on chromosome 1, associated with β-carotene accumulation in watermelon fruit. The QTL interval is approximately 20 cM on the genetic map and 2.4 Mb on the watermelon genome. Trait-linked marker was developed and used for validation of the QTL effect in segregating populations across different genetic backgrounds. This study is a step toward identification of a major gene involved in carotenoid biosynthesis and accumulation in watermelon. The codominant inheritance of β-carotene provides opportunities to develop, through marker-assisted breeding, β-carotene-enriched red watermelon hybrids. © 2017, Springer Science+Business Media B.V., part of Springer Nature.