Characterization of backcross generations obtained under field conditions from oilseed rape wild radish F1 interspecific hybrids:: an assessment of transgene dispersal
Characterization of backcross generations obtained under field conditions from oilseed rape wild radish F1 interspecific hybrids:: an assessment of transgene dispersal
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DOI：
10.1007/s001220050870
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发表时间：
1998-07-01
影响因子：
5.4
通讯作者：
Renard, M
中科院分区：
文献类型：
--
作者：
Chèvre, AM;Eber, F;Renard, M
通过两个回交代研究了抗草铵膦转基因油菜向野生萝卜的基因流动。在田间条件下，油菜-野生萝卜F-1杂交品种在野生萝卜授粉下的种子产量一直很低，平均每100朵花和每株种子产量分别为0.12粒和0.78粒。由此产生的“BC1”植株的细胞遗传学主要可以通过三种不同的基因组结构来解释：要么是ACRrRr， 2n = 37，要么是acrrr， 2n = 28（与母株染色体数目相同），要么是双二倍体AACCRrRr， 2n = 56。通过染色体配对进行基因交换的概率只有在Zn = 28或37染色体的植株上才高。由于未还原或部分还原的雌配子的生存能力，大多数“BC1”植株（81.9%）具有Basta抗性，而油菜特异性位点的分析表明，它们的传播随位点的不同而不同。尽管雄性育性较低（8.7%），但雌性育性较F-1杂交种有所提高，平均每100朵花和单株产量分别为1.4粒和11粒。在接下来的“BC2”代中，bar基因的传输率（57.2%）和染色体数量都有所下降，大多数植株的染色体数在24 - 27之间，10.5%与野生萝卜相似（2n = 18）。染色体数越低，“BC2”植株的育性越好。平均每100朵花和每株植物产生7.9和229.3粒种子。在此基础上讨论了基因流评价。
Gene flow from glufosinate-resistant transgenic oilseed rape to wild radish was studied over two backcross generations. Under field conditions,seed production from oilseed rape-wild radish F-1 hybrids due to pollination by wild radish was always low: on average 0.12 and 0.78 seeds per 100 flowers and per plant, respectively. The cytogenetics of the resulting "BC1" plants can be explained in the main by three different genomic constitutions: either ACRrRr, 2n = 37, ACRr, 2n = 28 (the same chromosome number as the mother plant), or by the amphidiploid AACCRrRr, 2n = 56. The probability of gene exchange through chromosome pairing was high only in plants with Zn = 28 or 37 chromosomes. Due to the viability of unreduced or partially reduced female gametes, most of the "BC1" plants (81.9%) were Basta resistant whereas the analysis of oilseed rape specific loci indicated that their transmission varied with the locus. In spite of low male fertility (8.7%), an improvement of the female fertility over the F-1 hybrids was observed with an average production of 1.4 and 11 seeds per 100 flowers and per plant, respectively. At the following "BC2" generation, the bar gene transmission (57.2% of Basta-resistant plants) decreased as did the chromosome number, with a majority of plants having between 24 and 27 chromosomes, with 10.5% similar to wild radish (2n = 18). The lower the chromosome number, the better the fertility of the "BC2" plants. On average, 7.9 and 229.3 seeds per 100 flowers and per plant were produced. Gene-flow assessment is discussed based on these data.