Inheritance of Rind Color and Reverse Striping in a Cucurbita pepo (subsp. texana) Cross

Several loci determining exterior fruit color have been characterized in C. pepo (5), among which are the L-1 and L-2 loci and the D gene. Interactions of multiple alleles at the L-1 and L-2 loci confer varying degrees of dark or light pigmentation, with the dominant alleles L-1 and L-2 conferring dark green coloration and their recessive counterparts l-1 and l-2 conferring a light green rind color (6). In addition, the l-1BSt allele causes fruit to exhibit broad, contiguous dark stripes in combination with the L-2 allele, and is recessive to L-1 but dominant to l-1 (3). A recently identified allele, l-2R, reverses the stripes (a phenotype known as “reverse striping”) in the presence of any striping allele—such as l-1BSt—at the other locus, such that the broad stripes in between the fruit’s vein tracts are lighter than the background color, which remains darker over the vein tracts (4). The D gene affects both fruit and stem color, with the dominant D allele conferring dark coloration to stem and fruit beginning at about 15-18 days after anthesis (6). Epistatic to l-1 and l-2, the D allele can cause fruits which would otherwise be light colored (i.e. l1/l-1, l-2/l-2) to be dark.

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