Strawberry High Frequency Regeneration System To Establish And Fructan Fructosyltransferase Gene Conversion

The regeneration of all star strawberry was established in the study. Effects of different factors on the regeneration of strawberry leaves were compared, and the factors of affecting transformation frequency were also studied. Agrobacterium LBA4404(pTSB) was used for transformation and then transgenic plantlets with fructan fructosyl transferase gene(FFT) of all star strawberry were obtained,and rooted very well in the rooting medium with Km90mg/L. By PCR analysis.the result proved that the FFT gene has been integrated into the genome of strawberry. By antifreezing experiments,the detect on electrical conductivities of the leaves,and the detect on the content of polysaccharides, the results proved that fructan fructosyl transferase gene in transgenic plantlets has been expressed. Concrete operations are as follows:(1) Tissue culture and establishment of high-frequency regeneration system of all star strawberry The stems and leaves were used in tissue culture and induced for regeneration, and the best medium for differentiation of leaf explant was TDZ1.0mg/L+NAA0.05mg/L +IAA0.2mg/L+GA0.25mg/L, the rate could get 81.82%; The rooting medium was MS₀.(2) On the basis of high-frequency regeneration system, Agrobacterium LBA4404(pTSB) was used for transformation, the factors of Agrobacterium state and its infecting time etc were expounded. Resistant plantlet rooted well in medium with Km90mg/L. PCR result showed rextended strip in transgenic plants coincidewith target strip in plasmid,while no strip extended in nontransgenic plants; this indicated foreign gene was integraded into strawberry.(3) The antifreezing experiments on the transgenic plantlets proved that there was obvious difference of growth between the transgenic and nontransgenic plantlets at -5℃. The antifreezing ability of the transgenic plantlets was much higher than that of nontransgenic plantlets.(4) The detect on electrical conductivities of the leaves of the plantlets was done.The electrical conductivities of the transgenic plantlets were less than that of nontransgenic plantlets at the low temperature, and the transgenic plantlets appeared stronger antifreezing ability.(5) The result of the phenotype showed that the transgenic plantlets appeared stronger antifreezing ability at the low temperature.(6) By the detect on the content of polysaccharides of plantlets, the polysaccharides content of the transgenic plantlets was higer thant that on nontransgenic plantlets.