Somatic Cell Hybridization Of Wheat And Bupleurum And Agrobacterium-mediated Gai Gene Into The Wheat

The PEG method was used for protoplast fusion between "Hesheng 3" wheat (Triticum aestivum) and Bupleurum scorzonerifolium Willd. This strain of wheat was also transformed via Agrobacterium-mediated shoot apical meristem transformation pathway with the gai gene. The main process and results of this research were as follows:Bupleurum scorzoneri folium protoplasts derived from cell suspension were fused by PEG method with that from the calli of wheat (Hesheng 3). The regeneration capacity of protoplasts was failed to differentiation due to the long-term subculture. But the capacity of differentiation of fused products was recovered through regeneration complementation. After the regenerated calli grew to about 1.5-2 mm in diameter, they were transferred onto MB2 medium. When the calli were large enough, they were transferred onto IB medium (MB medium added with 0. 5 mg/1 IAA and 0. 5 mg/1 6-BA) for plant regeneration. The morphology of the hybrids regenerated resembled that of Bupleurum scorzoneri folium.Sixteen out of total eighty regenerated clones capable of subsequent growth which were identified as hybrids by morphological and chromosome observation as well as esterase isozyme pattern; RAPD and 5SrDNA-space sequence analysis. Most of hybrid clones had characteristic bands of both parents and few new bands. Few hybrid calli have ability to regenerate, although most of the hybrids contain a complete of B. scorzoneri folium chromosome and some chromosomes or some DNA segments of wheat.The long cultivating experience indicates that the height of wheat is a key factor impact on the output of wheat except the diseases. The short wheat is inclined to increase grain yield at the expense of straw biomass to be more resistant to damage by wind and grain and to reduce the irrigation and fertilizer than the others.Agrobacten urn-mediated shoot apical meristem transformation method can directly infect the apical point of recipient plants and bypass the tissue culture limitations and is regarded as an improved method for wheat transformation. In this experiment, the primary vector pGREEN0029, in which the gai gene can' t replicate in Agrobacterium AGL1 was first replaced by the vector pR0K2.The screening of thirty-four out of total TO plants of "Hesheng 3" wheat revealed that they have specific bands of gai gene and the result of PCR-Southern blotting analysis confirmed it. The transformed plants have shorter phenotypes than the control. It is worth to study further.