Primary Exploration Of The Exogenous GA₃ Effects On Flower Induction In Chinese Rose

Rose（chinensis Rosa）as one of the important ornamental flowers in China,not only has a variety of colors,rich fragrance lasting,and has a very important economic value.In this experiment,the rose tissue culture seedlings as material,the effects of exogenous GA₃ on the length,effects of exogenous sucrose and GA₃ on flower formation,optimum conditions for the frozen section of flower buds and the changes of exogenous GA₃ and endogenous hormones in flower bud differentiation and elongation of the nodes were studied.The results are as below:1 Effects of exogenous GA₃ on the plant height of Chinese rose: With the concentration of exogenous GA₃ 0 mg/L,50 mg/L,100 mg/L or 200 mg/L treated the stem segment of the Chinese rose.The treatment of the exogenous GA₃ 200 mg/L has the most significant effect,the average plant height was 5.02 cm at 28 d.2 Effects of exogenous GA₃ on the flowering rate of Chinese rose: The treatment of the exogenous GA₃ with concentration of 100 mg/L make the highest flowering rate of 19.9 %.3 Effects of exogenous on the flower induction of Chinese rose: With the concentration of sucrose 70 g/L,60 g/L,55 g/L,40 g/L,30 g/L or 15 g/L in the medium.When the sucrose concentration was 40 g/L,there is a highest flowering rate of 87.1 % after cultured.4 Optimum conditions for the frozen section of Chinese rose flower buds: Fixed the flower bud with FAA and 10% glycerol,compared with fresh cut.After FAA fixed 2 h effect is the best condition.Fix the flower bud with FAA for 1.5 h,2 h,2.5 h or 3 h.FAA fixed 2 h is the best fix time.Embedded the flower bud with the OTC embedding liquid for 3 min,5 min,10 min,15 min or 20 min.It showed that 5 min is the best embedding conditions for the flower bud.5 Effect of GA₃ on endogenous hormone content in Chinese rose during flowering period: With the concentration of exogenous different GA₃ treated the stem segment of the Chinese rose.The external application concentration of 100 GA₃ mg/L can make the flowering period 7 d ahead,and the endogenous GA₃ content increased,so as to promote the differentiation of flower bud.And in the process of flower bud initiation,the endogenous IAA and the endogenous GA₃ content showed a synergistic trend.6 Effects of carbon source and GA₃ on endogenous hormone contents during flower formation in Chinese rose: With different GA₃ treatment,when sucrose concentration was 40 g/L in the medium,endogenous GA₃ content increased,showed that to some extent,the effect of GA₃ was promoted by sucrose.IAA plays a role in eliminating the dwarf effect caused by sucrose.After increasing the concentration of exogenous sucrose,the content of endogenous IAA in Chinese rose and the content of endogenous GA₃ showed a synergistic trend.