title: Low frequency of transgene flow from Bt/CpTI rice to its non-transgenic counterparts planted at close spacing.
abstract: Crop-to-crop transgene flow will affect seed purity of non-GM rice varieties, leading to unwanted consequences. To assess the maximum probability of transgene outflow in rice (Oryza sativa), gene flow experiments were conducted with three cultivation patterns with different mixed-planting proportions of adjacent GM and non-GM rice at two sites in Fujian and Hainan Provinces of China. Three GM rice lines containing two insect-resistance genes (Bt/CpTI) and their non-GM counterparts were used in the experiments to allow natural hybridization to occur. A hygromycin resistance gene was used as a selective marker for identifying hybrids. Based on the examination of > 645 700 geminated seeds, the result showed low frequencies (0.05-0.79%) of transgene flow from GM to non-GM rice at close spacing, although with significant variation among mixed-planting proportions. It is concluded that rice transgene flow will occur at a very low frequency (< 1.0%), even if the GM rice is planted at close spacing with non-GM rice, and high densities of GM rice cultivated in the neighborhood of non-GM rice will increase the probability of outcrossing with the non-GM rice.
authors.affiliation: The Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai 200433, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Rong
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Song
authors.forename: Jun
authors.initials: J
authors.lastname: Su
authors.forename: Hui
authors.initials: H
authors.lastname: Xia
authors.forename: Bao-Rong
authors.initials: BR
authors.lastname: Lu
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
mesh_terms: D002681:China; D002934:Cinnamates / Q000494:pharmacology; D004351:Drug Resistance; D051456:Gene Flow / Q000235:genetics; D006921:Hygromycin B / Q000031:analogs & derivatives / Q000494:pharmacology; D012275:Oryza / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D019076:Transgenes / Q000502:physiology*
chemical_list: D002934:Cinnamates; D006921:Hygromycin B; C026273:hygromycin A