A study of gene dispersal via pollen in Nicotiana tabacum using introduced genetic markers.
Agrobacterium tumefaciens was used to introduce two marker genes (kanamycin resistance and β-glucuronidase) into tobacco. These plants were grown in a series of field trials each consisting of a small plot of modified plants surrounded at various distances (1, 10 and 20 m) by non-modified receptor plants. Capsules from these receptor plants were harvested and samples of the seed were germinated on kanamycin-containing medium in laboratory conditions, as a screen for the presence of the resistance gene. Laboratory populations of seed could be screened in this way. Using these techniques, gene flow from the 'marked' plants could easily be detected. Although there were some differences in the absolute degree of gene dispersal in the different trials, there was an overall decline in transfer as distance from the marked plants increased. The potential for the use of introduced genetic markers in the study of gene flow is discussed.