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The watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus) has high variability for fruit size, shape, rind pattern, and flesh color. This study was designed to measure the qualitative inheritance of rind phenotypes (solid dark green vs. light green). For each of the 2 families, “Mountain Hoosier” × “Minilee” and “Early Arizona” × “Minilee,” 6 generations (PaS1, PbS1, F1, F2, BC1Pa, BC1Pb) were developed. Each family was tested in summer 2008 in 3 environments in North Carolina. Phenotypic data were analyzed with the χ2 method to test the segregation of Mendelian genes. Deviations from the expected segregation ratios based on hypothesized single dominant gene for solid dark green versus light green rind pattern were recorded, raising questions on the inheritance of this trait. Inheritance of solid dark green rind versus light (gray) rind showed duplicate dominant epistasis. Duplicate dominant epistasis gives rise to a 15:1 ratio (solid dark green:light rind pattern) in F2 generation. When both the loci are homozygous recessive, we observe light rind pattern. The g-1 and g-2 genes were identified to control light green rind when in homozygous recessive form. [ABSTRACT FROM PUBLISHER]

Winter hardiness is a complex trait and poor winter hardiness limits commercial production of winter oat (Avena spp.). The objective of this study was to identify quantitative trait loci (QTL) for five winter-hardiness component traits in a recombinant inbred line population derived from a cross between the winter-tender cultivar Fulghum and the winter-hardy cultivar Norline. Crown freezing tolerance, vernalization response, and photopenod response were evaluated in controlled environment studies. Heading date and plant height were evaluated over two seasons in Kinston, NC, and winter field survival was evaluated in five environments over two seasons in the mountains of North Carolina and Virginia. A partial genetic linkage map of regions believed to affect winter hardiness was developed using restriction fragment length polymorphism and simple sequence repeat markers. Most QTL were located on linkage groups FN3, FN22, and FN24. Quantitative trait loci were identified for all traits except photoperiod response, and epistatic interactions were identified for winter field survival, crown freezing tolerance, vernalization response, and plant height. Major QTL for winter field survival (R2 = 35%) and crown freezing tolerance (R2 = 53%) were identified on linkage group FN3, which was associated with an intergenomic reciprocal translocation between chromosomes 7C and 17. [ABSTRACT FROM AUTHOR]