Studies On Introduction Of Genomic DNA Of Thellungiella Halophila Into Lagerstroemia Indica L.

The salt-tolerant transgenic seedlings of L.indica L. were obtained by the technique of pollen tube pathway on the base of studies on its biological characteristics.(1) Habit of reproductive biology. There was not more than 0.5 h from pollination to pollen germination on stigma. It was the optimal time for exogenous DNA to be introduced into ovule when fertilization was completed at 24th h of post floral. In addition, there were many advantages in exogenous DNA introduction, such as a huge amount of pollen dropping on stigma, high germination rate of pollen, a huge bundle of pollen tubes going through style, several ovules in every locul.(2) Pollen activity. Iodine-potassium iodide method was most suitable for the determination of pollen activity of L.indica L.(3)Seed germination and raising seedlings. The seed germination on water-saturated filter paper in petri dish was promoted by soaking in water and chemical agents, respectively. seed immersion in 45℃ water for 4 h followed by a 20-hour continue soaking was the optimal pretreatment. The epigeal germination rate of seeds on medium (turf, vermiculite, perlite 2:1:1) was much lower than the germination rate of seeds in petri dish with the same pretreatment.(4) Salt tolerance of seeds and seedlings. There was inhibition in germination when seed was stressed by NaCl of 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%. 0.1% NaCl was suitable for the growth of 3～4 cm high seedlings.(5) DNA extraction and preliminary selection of reaction conditions for RAPD-PCR. SDS-high salt at low pH method was suitable for DNA extraction from halophyte leaves. Higher quantity and quality of genomic DNA of L.indica L. was obtained by the regular CTAB method after polysaccharides was removed when 0.5 h incubation time and 5% PVPP were used. The concentration of template DNA was critical to RAPD-PCR.(6) Introduction of genomic DNA of salt cress into crape-myrtle. 8106 putative transgenic seeds were obtained by the technique of direct dropwise and dropwise after servering style. 12 seedlings survived the 1-month irrigation of 0.3% NaCl.