Song Xiaoling, Liu Linli, Wang Zhou, Qiang Sheng
Weed Research Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
Pest Manag Sci. 2009 Aug;65(8):862-9. doi: 10.1002/ps.1766.
The possibility of gene flow from transgenic crops to wild relatives may be affected by reproductive capacity between them. The potential gene flow from two transgenic rice lines containing the bar gene to five accessions of weedy rice (WR1-WR5) was determined through examination of reproductive compatibility under controlled pollination.
The pollen grain germination of two transgenic rice lines on the stigma of all weedy rice, rice pollen tube growth down the style and entry into the weedy rice ovary were similar to self-pollination in weedy rice. However, delayed double fertilisation and embryo abortion in crosses between WR2 and Y0003 were observed. Seed sets between transgenic rice lines and weedy rice varied from 8 to 76%. Although repeated pollination increased seed set significantly, the rank of the seed set between the weedy rice accessions and rice lines was not changed. The germination rates of F(1) hybrids were similar or greater compared with respective females. All F(1) plants expressed glufosinate resistance in the presence of glufosinate selection pressure.
The frequency of gene flow between different weedy rice accessions and transgenic herbicide-resistant rice may differ owing to different reproductive compatibility. This result suggests that, when wild relatives are selected as experimental materials for assessing the gene flow of transgenic rice, it is necessary to address the compatibility between transgenic rice and wild relatives.
转基因作物与野生近缘种之间基因流动的可能性可能受它们之间繁殖能力的影响。通过在控制授粉条件下检测生殖相容性，确定了两个含bar基因的转基因水稻品系向5个杂草稻种质（WR1 - WR5）的潜在基因流动情况。
两个转基因水稻品系在所有杂草稻柱头上的花粉粒萌发、水稻花粉管沿花柱生长并进入杂草稻子房的情况与杂草稻自花授粉相似。然而，观察到WR2与Y0003杂交时双受精延迟和胚胎败育。转基因水稻品系与杂草稻之间的结实率在8%至76%之间。虽然重复授粉显著提高了结实率，但杂草稻种质与水稻品系之间结实率的排序未变。F(1)杂种的发芽率与各自的母本相似或更高。在草铵膦选择压力下，所有F(1)植株均表现出对草铵膦的抗性。
不同杂草稻种质与转基因抗除草剂水稻之间的基因流动频率可能因生殖相容性不同而有所差异。这一结果表明，在选择野生近缘种作为评估转基因水稻基因流动的实验材料时，有必要考虑转基因水稻与野生近缘种之间的相容性。
