Source: Plant Biotechnology Journal

Efficacy of a special screened greenhouse covered by duplex fine mesh in reducing maize outcrossing

Shin Watanabea, Tsunenori Sanoa, Hiroshi Kamada, Hiroshi Ezura*
Gene Research Center, University of Tsukuba, Ibaraki 305-8572, Japan
* E-mail: ezura@gene.tsukuba.ac.jp Tel & Fax: 81-29-853-7263
Received April 10, 2006; accepted July 6, 2006 (Edited by I. Smith)

ABSTRACT

Gene flow via pollen dispersal leading to the escape of transgenes is a potential concern associated with the
introduction of transgenic plants. Therefore, it is necessary to clarify the relationship between pollen dispersal and
outcrossing rate for strict biosafety management during risk assessment. Maize (Zea mays) is one of the crops most at risk for gene leakage via pollen flow into the environment. Here, we report the results of a cross-pollination field investigation using maize varieties showing a xenia effect with tricolor kernels, which allowed us to designate a pollen donor with natural outcrossing and one with reduced outcrossing (via a screened greenhouse) in the same experimental field at the same time. Although a previous study showed that a special screened greenhouse covered by 1-mm single fine mesh may be effective in reducing outcrossing in maize, we used 1-mm duplex fine mesh to reduce further the possibility of outcrossing. We report how a special screened greenhouse covered by 1-mm duplex fine mesh reduced pollen dispersal, and affected the outcrossing rate of non-genetically modified (GM) yellow maize in the greenhouse and white maize outside the greenhouse, compared to natural outcrossing.

Original paper: http://www.jstage.jst.go.jp/article/plantbiotechnology/23/4/387/_pdf

Source: CropBiotech Update

Duplex screen mesh reduces maize pollen flow

Researchers at the University of Tsukuba in Japan reported that a greenhouse covered with 1-mm duplex fine mesh reduced the outcrossing in maize by more than 75%. This is a result of the study by Shin Wanatabe and colleagues aimed to assess gene flow between maize plants inside the greenhouse and those outside. Under natural conditions, outcrossing in maize is reported to occur at 78% to 98%.

To determine the outcrossing rate, the researchers used yellow, black and white colored varieties. The colored varieties were designated as pollen donors. The presence of colored kernels on ears of white maize indicated cross pollination.

The complete article was published in Plant Biotechnology Journal.