Study On Inheritance Of Foreign Genes In Transgenic Arabidopsis Thaliana

In this study, the inheritance of foreign genes transformed into Arabidopsis thaliana viain-planta Agrobacteriam-mediated transformation were investigated with the progenies of thetransgenic plants carrying VI gene of CaMV and hpt gene, using Hyg-resistance phenotypicmarker, genetic analysis and PCR detection. It analyzed the segregation of self-pollinatedprogenies, the effects of transgenes on the gametes and the integrated loci of transgenes in thechromosomes. The conclusions are as followed: 1. The segregation of Hyg-resistance of the progenies of 29 T1 plants is complex, only thatof eight plants fixed the Mendelian fashion of 3:1, the rest deviated the ratio. There was singleinsertion locus in the chromosomes of the transgenic plants. The percentage of Hyg-resistanceplants is lower than expected, possibly due to the lost or silence of foreign genes. The segerationratio of T3 plants is 3:1 or 1:0. It also showed that the transgenes were delivered in thetransgenic progenies according to Mendelian Law of single gene segregation, and Hyp-resistancewas maintained in T3 and T4 generations of the transgenic Arabidopsis(over 30mg/L).The foreigngenes showed unstable in early generations, but he genes could be stabilized throughself-pollenation generation by generation. Homologous transgenic plants were obtained in T3generation, in which the resistance to Hyg was not segregated. 2. In the T4 generation, four pure transgenic lines was obtained. Reciprocal crosses wasmade between transgenic plants and the wild type plants. Analyzing the resistance to Hyg of F1and F2 progenies respectively, the results indicated that the inheritance and segregation of theresistance to Hyg of the transgenic plants was conditioned by a pair of dominant genes and wasnot affected by cytoplasm. The transgenes had no obvious effect on the gametes. 3. By analyzing F2 of hybrid combination of homozygous transgenic plants derived fromdifferent T1 transgenic plants, the foreign genes had been integrated into different locus ofhomologous chromosomes of P2 and P4 transgenic plants, and in the other combinations theywere integrated into heterologous chromosomes. 4. 49 Hyg-resistance seedlings were at random selected for PCR detection and almost gotthe target strip except one. It proved that the VI and hpt which integrated into the receipt genomewere linked and inherited stably among different generations. It is reliable to use theHyg-resistance as a phenotypic marker to detected transgenic plants.