Measuring gene flow in barley fields under Icelandic sub-arctic conditions using closed-flowering varieties

Genetic engineering is becoming an important tool for the improvement of plants for various forms of production. As varieties are developed for both food and non-food use different production lines must be kept separate. For good management practices of different lines an understanding of gene-flow is essential. Barley has been proposed to be an ideal plant species for genetic engineering as it has a low frequency of cross-fertilization and limited seed dispersal. In the present study, pollen-mediated exchange of genetic material between non-transgenic closed-flowering barley variants was examined in experimental plots under sub-arctic conditions in Iceland. The pollen-mediated dispersal was studied using the barley varieties Golden Promise and Ven, as pollen donor and acceptor, respectively. Only two hybrid plants were identified from a total of 700,000 screened plants giving a hybridization frequency of 0.0003%. It is concluded that adequate isolation distances and good management practices should suffice to prevent cross-fertilization between different lines of barley.