Study On Technique Of Tissue Culture And Photosynthetic Characteristics Of Fraxinus Variety ’Jinguan’

Fraxinus Variety‘Jinguan’, which belongs to Oleaceae, is a perennial woody plants. The golden leaves make it have good ornamental tree of landscape application prospect. The main methods of breeding are Cuttings and grafting. Because of longer growth cycle and growing more slowly, affecting its production in the garden applications. Therefore, it was necessary to establish the system of micro propagation, study leaf regeneration system and of photosynthetic characteristics Fraxinus Variety‘Jinguan’. Lay the foundation for production, cultivation and utilization of Fraxinus Variety‘Jinguan’. The major results were as follows:1. The explants were the axillary buds of 1-year branch. They were surface sterilized with 0.1%HgCl2+T disinfectant solution for 3min. The survival rate is 88.33% and the sterile explants are healthy growth. The optimum induction medium was MS supplemented with 6-benzylaminopurine(BA) 1.0mg·L～（-1）and IBA 0.2 mg?L-1.2. The best basic medium was Murashige and Skoog (MS). Sucrose is the best carbon source and its’best concentration was 30 g?L-1. The most suitable concentration of agar was 6 g?L-1. The best multiplication medium was MS supplemented with 6-BA 2.0 mg?L-1, KT 1.0 mg·L～（-1）and IBA 0.5 mg?L-1.3. 1/4MS with IBA 1.0 mg·L～（-1）was the optimum rooting medium, on which the rooting efficiency up to 75%.4. The optimum leaf callus induction medium was MS supplemented TDZ 1.0 mg·L～（-1）and 2,4-D 0.5 mg?L-1, on which culture 21 days in dark then transferred to the light condition. The quality of callus grew well. The best callus multiplication medium was supplemented 6-BA 0.5 mg·L～（-1）and 2,4-D 0.5 mg?L-1, on which the multiplication up to 9.7.5. By determination the pigment content obtained: Fraxinus Variety‘Jinguan’chlorophyll and carotenoids content lower than Fraxinus chinensis. But the ratio of carotenoids and chlorophyll on two plants, Fraxinus Variety‘Jinguan’is higher than Fraxinus chinensis.6. Different Fraxinus Variety‘Jinguan’and Fraxinus chinensis on the leaf structure as follows: Fraxinus Variety‘Jinguan’each leaf structure thickness are greater than Fraxinus chinensis. Fraxinus chinensis is only a layer of palisade tissue, but Fraxinus Variety‘Jinguan’has two to three layers of palisade tissue.7. Fraxinus Variety‘Jinguan’overall net photosynthetic rate is lower than Fraxinus chinensis. 12:00 and 14:00 light intensity was the strongest, Fraxinus Variety‘Jinguan’overall net photosynthetic rate was higher than Fraxinus chinensis. Transpiration rate and stomatal conductance of Fraxinus chinensis has declined at 12:00, while the Fraxinus Variety‘Jinguan’remained before the trend.8. The study of the chlorophyll fluorescence parameters of Fraxinus Variety‘Jinguan’and Fraxinus chinensis show that: FV/FM andΨO of Fraxinus Variety‘Jinguan’lower than Fraxinus chinensis. Dissipated energy flux per CS(at t=0) of Fraxinus Variety‘Jinguan’was higher than Fraxinus chinensis at 12:00 and 14:00, the other three phenomenological energy fluxes were lower than Fraxinus chinensis. Electron transport flux per RC(at t=0) was basically the same, and the other specific energy fluxes were higher than Fraxinus chinensis.