Potential Persistence of Escaped Transgenes: Performance of Transgenic, Oil‐Modified Brassica Seeds and Seedlings

摘要: We performed two experiments designed to assess the risk that seed-oil- modification transgenes will increase persistence of feral Brassica napus canola and interspecific hybrids B. wild rapa, a weedy relative. The first experiment, conducted at field sites in California Georgia where oil-modified be grown commercially, tested whether buried seeds transgenic high-stearate had increased survivorship dormancy. Performance type was com- pared nontransgenic null segregant parental lines. In California, no differences initial proportions dormant rates exit could detected between high- stearate its controls, suggesting low probability form larger or more persistent seed bank than nonpersistent controls. Georgia, although initially as lower exhibited detectable from bank, whereas both controls significant exit. Hence, escaped may persist for longer period this site. Differences highlight need conduct assessment over range crop mercialized. second greenhouse study, measured relative ability canolas X emerge four depths soil (0, 0.5, 4, 10 cm) their subsequent seedling vigor. lines carrying either gene transgene high-laurate production, using types also examined impact rapa hybrids. laurate compared parent. For all types, seedlings emerged cm, 0 0.5 cm. A higher proportion 4 cm control, but depths, slowly significantly less biomass control 2 wk following emergence. contrast, canola's total emergence timing not distinguished control. Although 2-wk by wk, equivalent due growth rate during period. different results oil-modification suggest even with similar functions should considered on case-by-case basis. From hybrids' emergence, accumulation were indistinguishable High-laurate rapidly greater hybrid Our indicate hybrids, shallow experience performance ad- vantages allow them perform well persistent,