| Populus simonii× P.nigra is one of the main forested tree species in Heilongjiang Province.However,its growth is still limited in saline-sodic and arid regions.Therefore,to create transgenic poplar with high stress resistance,Populus simonii×P.nigra was utilized as transgenic receptor by genetic engineering technology and the transgenic poplar with TaLEA,betA,PsnWRKY70 gene were obtained by our tesearch team.At the same time,people’s attention was gradually attracted by the safety of transgenic plants.The environmental safety evaluation of transgenic poplar is of great significance for its industrialization and application.In this experiment,we investigated transgenic poplar plantations grown in semi-arid and slight saline alkali regions.Then the evaluation of foreign gene stability,growth stability and environmental safety was carried out.The specific research results were as follow:(1)Molecular detection of the 9-year-old transgenic poplar with TaLEA gene,13-year-old transgenic poplar with betA gene confirmed the foreign gene was still integrated in the genome of which could express stably.(2)The T1 of betA transgenic poplar was selected as the grew best line in slight saline alkali region,and its mean value of volume at 13 years was 48.25%higher than that of the WT,the survival rate of which was 81.25%.In the multisite joint analysis of the 9-year-old TaLEA transgenic poplar plantations,the XL-7,XL-9 and XL-13 were selected for their best growth adaptability in the slight saline alkali and semi-arid regions.We predicted the amenable regions of each line,XL-1 and XL-9,which showed the best growth adaptability in semi-arid regions.At 9-year-old,the volumes of them was 16.22%and 15.58%higher than that of the WT.Besides,the genetic gains were 36.98%and 36.28%respectively.(3)NaCl stress experiment was performed on the 3 transgenic poplar lines among selected lines for the purpose of comparing the difference of salt tolerance between transgenic poplar once more.The results illustrated that interference expression lines of PsnWRKY70 transgenic poplar(b15,b20),T43 and T8 of betA transgenic poplar has the most salt tolerance.Furthermore,through the analysis of the growth adaptability of the above transgenic poplar plantations in Xinjiang and Cuohai forest farms,the best transgenic poplar were the whole of betA transgenic lines and the whole of Psn WRKY70 interference expression lines respectively.(4)The risk of foreign(target)gene drift and its effect on soil microbial quantity and community composition of transgenic poplar with TaLEA,betA and PsnWRKY70 gene were studied.The results demonstrated that the target gene did not drift.(5)The number of bacteria,fungi and actinomycetes in rhizosphere soil of transgenic poplar was detected by dilution plate method.It was found that the introduction of foreign gene had a significant effect on the number of microorganisms in rhizosphere soil of poplar.(6)To analyze the variation of bacterial and fungal community composition in rhizosphere soil of transgenic poplar,16S rRNA and ITS high-throughput sequencing were utilized.The results declared that the abundance of potential probiotics and mycorrhizal fungi in rhizosphere bacterial and fungal communities of transgenic poplar increased,while the abundance of pathogenic fungus decreased.This effect may be caused by the development stage,seasons and other factors.It is necessary to further study of the rhizosphere microorganisms of transgenic poplar in different development stages,different years and microbial community structure.However,according to the current research results,it is safe to plant transgenic poplar for its planting environment.The results laid a foundation for the subsequent production experiment of transgenic poplar. |
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