Species Crosses in the Genus Cucurbita

Various attempts were made to cross different varieties belonging to three species. Successful crosses have been made as follows: (1) Hubbard Squash (C. maxima) as the pistillate parent x Common Field Pumpkin (C. pepo). Viable seeds which produced vigorous fertile Fl plants were secured from this cross. The reciprocal cross produced normal fruits, but no fertile seeds. (2) Hubbard Squash (C. maxima) as the pistillate parent x Large Cheese Pumpkin (C. moschata) produced fruits which contained no fertile seeds, although otherwise normal. (3) Scalloped Squash (C. pepo) as the pistillate parent x Large Cheese Pumpkin (C. moschata) produced fruits containing no fertile seeds, although otherwise normal. (4) Bush Crookneck Squash (C. pepo) as the pistillate parent x Scalloped Squash (C. pepo) produced many fertile seeds. In the last three cases mentioned no reciprocal crosses were made. In the last three cases mentioned all back crosses produced fertile seed