喷施GA3和6-BA对“富士”苹果顶芽内源激素及成花成枝的影响

摘要

为探讨外源GA3、6-BA对“富士”苹果大小年现象调控机理及其在成花成枝中的作用,试验以4年生“富士”苹果树为材料,分别在不同生长时期、相同浓度GA3、6-BA喷施处理树体和以不同喷施次数、不同浓度的GA3、6 BA处理树体,利用超高效液相色谱法测定枝条顶芽中内源激素(GA3、IAA、ABA、ZT)含量,同时考察不同类型枝条成花率、成枝率和枝条长度.结果显示:(1)在不同生长时期喷施GA3促进了顶芽中内源GA3和ABA含量的积累,抑制了ZT和短枝IAA的合成,同时降低了不同类型枝条的成花率、促进了生理分化前期短枝的成枝率;6-BA处理增加了所有枝条顶芽中GA3、ABA以及短枝顶芽中IAA和中长枝顶芽中ZT的合成,从而促进了花芽生理分化前期不同类型枝条的成花率、短枝的成枝率以及中长枝的伸长,但对短枝的伸长有抑制作用.(2)单次喷施GA3抑制了所有枝条顶芽中IAA的合成,促进了所有枝条顶芽中GA3、ABA以及短枝顶芽ZT含量的积累,使得成花率降低、成枝率增加、枝条伸长减小,GA3浓度越大对顶芽中ZT合成的抑制越明显.多次喷施GA3增加了所有枝条顶芽中GA3和IAA的积累,短枝中ABA含量减小而中长枝增加,并使得成花率降低,成枝率减小,但对ZT含量和枝条伸长无显著影响.(3)单次喷施6-BA增加了短枝顶芽中GA3和ABA含量以及所有枝条中ZT的含量,但抑制了中长枝GA3和ABA的合成以及所有枝条顶芽中IAA的合成;使得成花率降低,成枝率增加,抑制了短枝枝条伸长而促进了中长枝伸长;多次喷施6-BA使得所有枝条顶芽中GA3和IAA含量增加,短枝ABA含量减小,短枝ZT含量增加而中长枝ZT含量减小,并抑制了所有枝条成花率和短枝的伸长,但对成枝率和中长枝的伸长无显著影响.研究表明:不同生长时期使用外源激素可以促进顶芽中GA3和ABA的合成,但对IAA、ZT的含量以及成花率、成枝率、枝条长度影响随处理时期的不同而有所改变.喷施次数和浓度对内源激素的合成、成枝率以及枝条的伸长有不同的调节作用,但都抑制了花芽的分化,使成花率降低.%The objective of the present study is exploring the effect of exogenous GA3 and 6-BA on biennial bearing,flowering and branching in "Fuji".Using 4-year-old "Fuji" trees,we sprayed 75 mg/mL GA3 or 6-BA at several different growth periods.we also sprayed 50 mg/mL and 100 mg/mL GA3 or 6-BA at different spraying repeat (single spraying or multiple spraying).The flowering rate,branching rate and endogenous hormones (GA3,IAA,ABA,ZT) in different types of tree branches were tested.The results showed that:(1) at all growth periods,GA3 treatment promoted the accumulation of endogenous GA3 and ABA in terminal buds,but inhibited the synthesis of ZT in all types of branches and IAA in short branches,decreased the flowering rate of different types of branches,promoted branching rate in short branches.6-BA treatment promotes the synthesis of GA3,ABA,IAA,ZT and flowering rate in all terminal buds of different branches,the branching rate of short shoots,the elongation of long branches also increased.(2) Single spraying of GA3 inhibited the synthesis of IAA,promoted the accumulation of GA3,ABA in all branches' terminal buds and ZT in short branches.The flowering rate and the elongation of branch were inhibited,the shoot forming rate was promoted by this treatment.the effect of GA3 on ZT increased with the increase of GAs concentration.Multiple spraying of GA3 increased the accumulation of GA3 and IAA in all terminal buds,but decreased the content of ABA in the short branches,had no effect on ZT.The long branch increased,the flowering rate and the branch forming rate decreased by this treatment.(3) Single application of 6-BA increased the contents of GAs and ABA in short terminal buds and ZT content in all branches,but inhibited the synthesis of GAs and ABA in long branches and IAA synthesis in all terminal buds.It inhibited the elongation of short branches and promoted the elongation of long branches.Multiple spraying of 6-BA increased the contents of GA3 and IAA in all terminal buds and ZT in short branches,decreased the contents of ABA in all branches and ZT in long branches,and inhibited the flowering rate and elongation of all branches.There was no significant effect on the branching rate and the elongation of long branch.In conclusion,the use of exogenous hormones at different growth stages can promote the synthesis of GA3 and ABA in the top buds,but the effects of the contents of IAA,ZT,the rate of flower formation,the branching rate and the length of the branches vary with the treatment period.The spraying times and concentrations had different effects on endogenous hormones synthesis,shoot forming rate and branch elongation,but they all inhibited flower bud differentiation and flowering rate.