Effect of a special screened greenhouse covered by fine mesh on maize outcrossing

Abstract

Risk assessment and management of gene flow via pollen dispersal from genetically modified (GM) plants is critical. To minimize the likelihood of undesirable outcrossing, it is important to better understand the relationship between pollen dispersal distance and outcrossing rate in objective materials under physical containment. This study examined how a special screened greenhouse for Type-2 use, covered by a fine, 1-mm mesh reduced pollen dispersal and affected the outcrossing rate of non-GM yellow maize in the greenhouse and silver maize outside the greenhouse. Results suggest that the mesh-covered greenhouse was effective in reducing the outcrossing rate as a whole, although it may be less effective in reducing the longest distance of pollen dispersal. Further, the isolation distance threshold for the screened greenhouse is discussed in relation to risk assessment.