| Blueberry was perennial deciduous or evergreen shrubs which subordinated to Vaccinium of Ericaceae.Due to the shallow roots of blueberry plants and root fibers is underdeveloped, soil pH, soil moisture, management practices and other conditions are more stringent requireds, blueberry is so difficultly rooting as to the main use of tissue culture technology for rapid propagation of blueberries at present.However,tissue culture has its drawbacks in high pollution and difficult seedling.The study found growth hormone added to the medium containing sucrose, boron, vitamin B can further improve rooting plantlets.Two varieties of one-year-old Greenwood cuttings of Southern highbush blueberry were taken as materials in this experiment, the effect of different concentrations of Boron, vitamin B, sucrose compound certain concentration of IBA on rooting of greenwood cuttings were systematically studied, and the changes of endogenous hormones and IAAO activities were explored during their rooting process in order to ensure the quality of the premise of blueberries, for large-scale rapid propagation of new theoretical and practical basis.The result showed:(1).Cuttings treated with different concentrations of boron compound IBA, its base cortex auxin IAA were higher than CK (IBA alone treatment) from callus tissue to adventitious root formation period (1～45 d),generally significantly higher than the rooting treatment agent added sucrose and vitamin B (P<0.01).ABA leavels of cuttings treated by boron compound IBA were significantly higher than the rest of the deal in callus formation period (1-15 d).But with the extension of cutting time, the boron treatments reduced the ABA content during adventitious root formation cuttings cortex (30～45 d).When the cuttings to 45d, the ratio of IAA and ABA from S33 and S4 cuttings treated by boron compound IBA were the highest of all,IAA/ABA of 300 mg·L-1 boron compound IBA treatment respectively reached 2.7565 and 3.0475,while the ratio of CK (IBA treated separately) were significantly lower than the rest of hormone treatments (P<0.01), only 1.4428 and 1.7993.Boron is added to promote rooting Southern highbush blueberries due to its improve their levels of endogenous IAA and reduce endogenous ABA during the adventitious root formation.(2)When cutting 45 d, rooting ration under sucrose compoud IBA were slightly better than IBA alone handled.But from the final rooting view (cuttings 80 d), sucrose complex IBA dealing have basically the same rooting rates with the boron compound.The cuttings of S33 and S4 treated respectively by 5% sucorse+200 mg·L-1 IBA and 2% sucorse+50 mg-L-1 IBA,their rooting rates have reached 91.18% and 85.71%.It explains that sucrose can significantly improve the efficiency of rooting cuttings in rooting late (45-80 d).(3)Vitamin B promotes the growth of Southern highbush blueberry callus while enhance the role of rooting cuttings during adventitious root formation is not obvious.The rooting treated by vitamin B complex IBA of S33 was significantly lower than treated separately. Not only that Vitamins B promote callus growth leads to IAA content continues to reduce in the formation of root primordia in callus formation,but also ABA levels rise slowly in the late cuttings.High concentrations of ABA and low concentrations of IAA did not help root differentiation.(4)IAA0 activity gradually increased with the increase of cutting time by all treatments.High activity IAAO reduce the level of IAA and conducive to induce roots group. Some of the cuttings treated by sucrose,boron and vitamin B,their IAAO activity decreased with the rooting process continues.IAA levels rise rapidly and promote adventitious root elongation. |
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