USDA 846-1 Fractal Melon and Derived Recombinant Inbred Lines

Abstract

Genes residing in highly branched, fractal melons [Cucumis melo ssp. agrestis (Naud.) Pangalo] have the potential for increasing yield in dessert melon types, C. melo L. ssp. melo (Zalapa et al., 2006). A horticulturally unique C. melo ssp. agrestis germplasm, designated CR1 (Fig. 1), was received in 1995 from Mr. Claude Hope, Cartago, Costa Rica, by the USDA-ARS Cucumber and Melon Breeding Project, Madison, WI. The earlyflowering (in Wisconsin), monoecious CR1 is rapid-growing, indeterminate and bears many (up to 100 fruits/plant) small (3 to 6 cm in diameter) (Staub et al., 2004; Zalapa, 2005; Zalapa et al., 2006) fruits on an indeterminate, highly branched (six to 12 primary branches) plant with standard length internodes, i.e., not compact, si (Denna, 1962; Paris et al., 1984). The architectural type of CR1 is unique and distinct from vining (Rosa, 1924), dwarf (Denna, 1962; Mohr and Knavel, 1966), and birdnest (Paris et al., 1981, 1982, 1984) plant habits, and thus, is designated here as a ‘‘fractal’’ type (Prusinkiewicz and Lindenmayer, 1990) because of its highly branched, radiant growth habit when compared with standard vining phenotypes such as ‘Top Mark’ (Fig. 1). The fractal architecture of CR1 is, thus, a function of its internode length and comparatively high numbers of primary, secondary, and tertiary branches (Zalapa, 2005). This report describes the highly branched, fractal-type melon USDA 846-1 line and 81 derived recombinant inbred lines (RIL) that were made available to melon breeders for development of U.S. western shipping melons with a highly branched, fractal-type architectural growth habit to increase genetic diversity and yield potential for commercial field production. This germplasm will be useful in breeding and genetic studies for deployment of marker-assisted selection for quantitative traits associated with fruit yield and quality.