Journal or Publishing Institution: Weed Research Laboratory, Nanjing Agricultural University
Author(s): Aiqin, Z., Sheng, Q. and Xiaoling, S.
Article Type: Study
Record ID: 1750
Abstract: The spontaneous hybridization of transgenic herbicide-resistant oilseed rape (Brassica napus ) with wild B. juncea has been reported. But the potential impact produced by F1 receiving pollen from conventional cultivated oilseed rape is unclear. The first backcross with F1 (wild B. juncea as maternal parent and glyphosate-resistant or glufosinate-resistant transgenic oilseed rape as paternal parent) used as maternal parent and 5 conventional cultivated oilseed rape (B. napus) varieties as paternal parents was conducted by hand pollination. The silique length and seed number per silique were measured after backcross. The transgene transmitted frequencies were tested by bioassay and PCR. The fitness of the first backcross generation (BC1) and the first progeny of the first backcross generation (BC1F1) were measured in greenhouse. The results showed that all the first backcross produced less than 1 seed per silique. There was no difference in germination percentages of different BC1 and BC1F1, which were all significantly lower than that of wild B. juncea. The herbicide-resistant transgene was maintained in BC1 and BC1F1 at 49-62% and 52-64% ratios. The composite fitness of different BC1 with herbicide-resistant gene was similar; however the fecundity of all BC1 was low, with fewer siliques per plant and fewer seeds per silique. The composite fitness of BC1F1 was similar with wild B. juncea; however the fecundity of all BC1F1 was lower than that of wild B. juncea. Compared with BC1, BC1F1 produced more siliques and seeds per slique. The results demonstrated that F1 with herbicide-resistant gene could backcross with conventional cultivated oilseed rape and produce BC1 and BC1F1 with herbicide-resistant gene. The genotype of conventional cultivated oilseed rape affected the potential impact produced by backcross between F1 and conventional cultivated oilseed rape. Such ecological influence should not be ignored.
Keywords: herbicide-resistant transgenic oilseed rape; gene flow; wild Brassica juncea; cultivated conventional oilseed rape; backcross; fitness
Citation: Aiqin, Z., Sheng, Q. and Xiaoling, S., 2014. Fitness of backcross between F1 (wild B. juncea× herbicide-resistant transgenic oilseed rape) and 5 conventional cultivate varieties. Weed Research Laboratory, Nanjing Agricultural University.
