Description:
Origin and breeding history: Four species in the pedigree of NY 247: Cucurbita pepo, C. ecuadorensis, C. martinezii, and C. moschata. Embryo culture was used to make the interspecific cross with C. ecuadorensis. Pedigree selection was followed, with selection made in segregating generations for virus resistance and horticultural type. Resistant lines were intercrossed to combine resistance to different viral diseases and to overcome the genetic barrier to transferring homozygous resistance to zucchini yellow mosaic virus from C. ecuadorensis to C. pepo. The parentage of ‘Whitaker’ is complex beginning with crosses of the cultivars ‘Black Jack’ and ‘Butternut’ with the wild species Cucurbit ecuadorensis and C. martinezii. (C. martinezii was subsequently renamed C. okeechobeensis subsp. martinezii.) Seed for these species was obtained from the late Dr. T. W. Witaker of the USDA, ARS, La Jolla, CA and did not have a Plant Introduction number or other designation except for species name and the site of collection. Dr. Whitaker collected the Cucurbita ecuadorensis accession 5 miles west of Guayaquil, Ecuador and C. martinezii at Vera Cruz, Mexico. The cros of ‘Black Jack’ x C. ecuadorensis was made in 1980 and the cross of ‘Butternut’ x C. martinezii was made in 1977. Selection for horticultural type refers to fruit and vine characteristics of horticultural importance including bush vine habit with plant semi-erect and not sprawling; foliage relatively sparse, not so dense as to obscure the fruit and make harvesting difficult; fruit mostly straight, infrequently curved or constricted; fruit color green, striped; no fruit another color or non-striped; and uniformity for yield and earliness. No off-types are known for this variety. Variants will occur in ‘Whitaker’ as in any other squash variety and will include >5% curved or constricted fruit. Breeding line 95-247 was homozygous for disease resistance and was uniform for vine and fruit type in the F3 generation in 1995. It was self-pollinated and found to be stable and uniform for the next two generations before it was released.