Gene Flow between Potato Cultivars under Experimental Field Conditions in Argentina

Abstract

Wild and cultivated potatoes form a polyploid series with 2n = 2x to 2n = 6x (x = 12). In nature, they are separated by external and/or internal hybridization barriers that, when incomplete, provide opportunities for gene flow and introgression. Isolation distances estimated in one environment are not necessary extrapolable. As a starting point for pollen-mediated gene flow risk assessment in potatoes, an experiment was set up in the field in one of the major potato growing area in Argentina, with two pollen-pistil compatible tetraploid commercial cultivars with differential molecular marker patterns. The field design consisted of a 10 × 10 m central square with the pollen donor, surrounded by circles with a male sterile pollen recipient, set every 10 m up to 40 m. The crop was managed as a perennial, and data were recorded over 2 years. Seeded berries were obtained in both years at 30 and 40 m away from the center; all of them contained hybrid seeds as revealed by electrophoretic profiles. We consider that a minimal required isolation distance of 100 m or more would be more suitable for preventing undesirable gene flow in the area.