RECONSIDERATION OF POLLEN DISPERSAL DATA FROM FIELD TRIALS OF TRANSGENIC POTATOES

During the initial field evaluation of transgenic plants, it is usual to isolate them genetically from other plants of the same species. Sev eral field experiments on potatoes, using transgenes as markers, have shown that transgene dispersal by pollen to other potato plants is lim ited and very unlikely at distances over 10 m. In a recent study in Sw eden, a frequency of transgene-containing progeny of over 30% is repor ted from non-transgenic potato plants grown at distances of 10-1000 m from transgenic plants containing nptII and gus marker genes. Data fro m the Swedish study is discussed along with other relevant observation s, and it is concluded that the high frequency of gene dispersal in th at study results from a high frequency of false positives during PCR a nalysis of the nptII gene. From the data available in potato, it is co ncluded that a distance of 20 m is generally adequate for the initial field evaluation of transgenic potatoes containing novel gene construc ts.