3种修剪方法对文冠果芽内源激素含量和萌芽成枝的影响

Effects of three pruning methods on endogenous hormone and shoot growth of Xanthoceras sorbifolia Bunge buds

【目的】研究拉枝、刻芽、短截对文冠果同一枝条不同部位芽内源激素含量和萌芽成枝的影响,探讨促进文冠果花芽分化、提高产量的最佳修剪方式。【方法】对60株4年生文冠果样树的1年生枝条分别进行拉枝(角度分别为45°,60°,90°)、短截(轻短截、中短截、重短截)、刻芽(单刻芽、环刻芽)处理,以不拉枝枝条为对照1(CK1),以不刻芽和不短截枝条为对照2(CK2),研究各处理对文冠果1年生枝条顶部、上部、中部和下部芽的赤霉素(GA3)、生长素(IAA)、脱落酸(ABA)和玉米素(ZT)含量,GA3/ABA、ZT/IAA值,以及枝条生长发育和坐果的影响。【结果】(1)随着拉枝角度的增大,顶部和上部芽的GA3、IAA、ZT含量逐渐减少,ABA含量则逐渐增加,而中部和下部芽内源激素含量呈相反变化趋势。随着拉枝角度的增大,顶部和上部芽的GA3/ABA逐渐减小,而中部和下部芽呈相反趋势;顶部和中部芽的ZT/IAA逐渐减小,下部芽逐渐增大。60°拉枝枝条萌芽率为78.62%,单支可孕花数为28.44,单支坐果数为1.33,均为最高。(2)刻芽枝条上、中、下部芽内GA3、IAA、ZT含量增加,ABA含量减少。单刻芽处理枝条下部芽的GA3、IAA、ZT含量分别为2 139.94,323.82,282.98ng/g,均明显高于CK2处理;ABA含量最低,为183.12ng/g,明显低于CK2处理,GA3/ABA和ZT/IAA值分别达到11.71,0.87。单刻芽处理枝条的萌芽率达到73.35%,可孕花数达到21.78,单枝坐果数达到1.44个,均为最高。(3)随着短截程度的增强,枝条中部和下部芽的GA3、IAA、ZT含量上升,ABA含量降低。中短截枝条中部芽的GA3、IAA和ZT含量分别为2 580.53,1 290.27,269.55ng/g,均显著高于CK2,ABA含量为112.75ng/g,显著低于CK2和轻短截处理;GA3/ABA、ZT/IAA分别为22.89,0.68,显著高于其他处理。中短截的萌芽率为64.07%,单枝可孕花数、单枝坐果率分别为19.11和1.22。【结论】拉枝60°、单刻芽和中短截可以有效改变文冠果内源激素在枝条内的分布,明显削弱顶端优势,是适合文冠果的最佳修剪方式。

[Objective] This experiment analyzed ting back on endogenous hormone content and shoot the effects of bending branch, notching buds and cut- growth to obtain the optimal pruning method for im-proving flower bud differentiation and yield. [Method] A total of 60 Xanthoceras sorbifolia Bunge plants were used to study effects of bending branch, notching bud and cutting back on budding rate, shoot growth,contents of endogenous hormones （GA3 ,IAA,ABA and ZT） ,GA3/ABA and ZT/IAA. The treat- ments include bending branch with angles of 45°, 60°,and 90°,single and ring notching,as well as light, middle and heavy cutting back. No bending was control 1 （CK1） and no notching and cutting back was con- trol 2 （CK2）. [Result] （1）The contents of GA3 ,IAA and ZT and GA3/ABA ratios of top and upper buds decreased while those of middle and basal buds increased with the increase of branch angle. The contents of ABA showed opposite trend. Budding rate, number of fertile florets and fruitlet with the branch bending angle of 60° were 78.62%,28.44 and 1.33,respectively. （2）The contents of GAa,IAA and ZT of upper, middle and basal buds increased with notching bud treatment,while ABA contents decreased. Single notc- hing bud was better than ring notching bud. The contents of GA3, IAA, ZT and ABA in the base part of single notching bud were 2 139.94,323.82,282.98,and 183.12 ng/g, significantly higher than other treat- ments. The trend of upper and central part was the same as the base part. Budding rate, number of fertile florets and fruitlet of single notching bud were 73.35% ,21.78 and 1.44,respectively. （3）The contents of GA3 ,IAA and ZT of middle and basal buds increased with the increase pruning cut length. The contents of GA3 ,IAA and ZT in the central part of branch middle cutting back were 2 580.53,1 290.27,and 269.55 ng/g,significantly higher than other treatments. Budding rate of 64. 07% was significantly higher than those of CK2 and other treatments. Number of fertile florets and fruitlet of middle cutting buds were 19.11 and 1.22, respectively. [Conclusion] For Xanthoceras sorbifolia Bunge, the distribution of endogenous hor- mone was changed and apical dominance was weakened by branch bending with angle of 60°, single notc- hing and middle cutting back.