转基因三倍体毛白杨花粉活力及枯落物外源基因检测

目的长期持续的开展转基因林木安全性评价研究，对林木遗传改良育种工作的开展和转基因林木的生物安全性评价具有重要意义。方法对田间种植11年和13年的转AhDREB1基因三倍体毛白杨（Populus tomentosa × P.bolleana）× P.tomentosa]花粉活力和杂交结实率进行检测。此外，对自然条件下转基因三倍体毛白杨枯落物中外源基因进行检测，并从转基因三倍体毛白杨林下根际土壤中筛选出44株卡那霉素抗性细菌，对其基因组DNA进行PCR检测。结果MTT和TTC染色检测结果表明转基因三倍体毛白杨花粉没有活力，杂交试验结果再次表明转基因三倍体毛白杨花粉不具备可授性和育性，其杂交结实率为0。转基因三倍体毛白杨的枯落物（枝、茎和叶）无论是埋在土里，飘落在地表，飘落在草坪上，其外源基因在3个月后均未能检测到。种植13年的转基因三倍体毛白杨枯落物中的外源基因暂未水平转移到根际土壤可培养细菌基因组中。结论未发现大田种植13年的转基因三倍体毛白杨对周围生态环境造成显著影响。 

Pollen vigor and detection of exogenous genes of litter for transgenic triploid Populus tomentosa

ObjectiveLong-term and continuous research on the safety evaluation of transgenic trees is significant to the development of forest tree genetic improvement and the biosafety evaluation of transgenic trees.MethodIn this study, the pollen vigor and hybrid seed setting rate of transgenic triploid Populus tomentosa with AhDREB1 gene were continuously observed in the field for 11 years and 13 years. In addition, the foreign genes in the transgenic triploid Populus tomentosa were detected under natural conditions, and 44 kanamycin-resistant bacteria were screened from the rhizosphere soil of transgenic triploid P. tomentosa, and the genomic DNA of bacteria was used for PCR detection.ResultThe results of MTT and TTC staining showed that the transgenic triploid Populus tomentosa pollen had no vigor. The results of hybridization test again showed that the transgenic triploid Populus tomentosa pollen may not have the cultability and fertility, and the hybrid seed setting rate was zero. The litter (branches, stems and leaves) of the transgenic poplars was buried in the soil, falling on the surface and falling on the lawn, and the foreign genes were not detected after 3 months. The exogenous gene in the 13-year-old transgenic triploid Populus tomentosa litter had not been transferred horizontally to the rhizosphere soil culturable bacterial genome.ConclusionThis study did not find that the transgenic triploid P. tomentosa, which was grown in the field for 13 years, had a significant impact on the surrounding ecological environment.