Fecundity of transgenic wild–crop hybrids of Cucurbita pepo (Cucurbitaceae): implications for crop-to-wild gene flow

Journal or Publishing Institution: Heredity

Study: http://www.nature.com/hdy/journal/v86/n6/full/6888900a.html

Author(s): Spencer, L.J. and Snow, A.A.

Article Type: Peer Reviewed Study

Record ID: 2193

Abstract: Hybridization between crops and their weedy or wild relatives is an area of concern because the widespread use of genetically engineered crops may allow novel, beneficial transgenes to enter nearby populations. We compared fitness components of wild Cucurbita pepofrom Arkansas, USA, with wild–crop hybrids derived from yellow squash (a cultivar of C. pepo with transgenic resistance to two viruses). Wild and hybrid progeny were grown in agricultural fields in Arkansas (1996–98) and Ohio (1996) in six similar experiments. Cross types (wild and hybrid) did not differ significantly in seedling survival, which exceeded 85% in all cases. In Ohio, where more detailed observations were made, hybrid plants produced 41% as many male flowers, 21% as many female flowers, and 28% as many seeds as wild plants. At all sites, flowering periods of the two cross types overlapped extensively. Putative virus symptoms were more common in wild plants than in hybrids. Lifetime fecundity varied considerably among sites and years. The average fecundity of hybrids ranged from 453 to 4497 seeds per plant and represented 15% – 53% of the numbers of seeds produced by wild plants in the same experiments. These results suggest that the F₁generation does not represent a strong barrier to the introgression of neutral or beneficial crop genes into free-living populations of C. pepo.

Keywords: Agricultural Crops, Genetic Crosses, Cucurbita, Fertility, Gene Frequency, Genetic Hybridization, Phenotype, Plant Diseases, Genetically Modified Plants, Survival Rate, Genetics, Virology, Physiology, Plant Hybridization, Cucurbita Pepo, Gene Flow, Squash, Transgenic, Wild-Crop Hybridization

Citation: Spencer, L.J. and Snow, A.A., 2001. Fecundity of transgenic wild–crop hybrids of Cucurbita pepo (Cucurbitaceae): implications for crop-to-wild gene flow. Heredity, 86(6), p.694.