扁桃生理落果期不同组织激素浓度的动态变化及其对落果的影响

Dynamic Change of Hormones in the Different Tissue of Almond during the Physiological Fruit Drop and Its Effect on Fruit Drop

为探明扁桃幼果生理脱落与GA3、IAA和ABA等3种激素的关系,以新疆‘纸皮’扁桃为试材,分析新梢、结果枝组、幼果和果柄(包括正常发育幼果和果柄、即将脱落幼果和果柄)中3种内源激素浓度的动态变化规律,并分别涂抹3种外源激素调查其对坐果率的影响。结果表明:(1)‘纸皮’扁桃幼果脱落期和新梢生长期重合,扁桃生理落果期不同组织中3种内源激素浓度变化趋势与新梢生长期和幼果脱落期的动态特征基本一致。(2)扁桃生理落果期间,正常的和即将脱落的幼果及其果柄中内源激素浓度呈规律性变化,即:GA3和IAA浓度表现为正常果和正常果果柄始终大于相应的落果和落果果柄,而内源ABA浓度表现则与之相反,同时对应外源涂抹试验也印证了幼果和幼果果柄中高GA3和IAA浓度、低ABA浓度有利于扁桃坐果。(3)新梢和幼果中对应内源激素之间的浓度平衡关系也是调控扁桃幼果生理脱落的重要因素,即:新梢与幼果的GA3比值和IAA比值增大、而ABA比值减少将会促进幼果脱落,反之则减缓幼果脱落。

In order to make clear the relationship between physiological fruit drop and 3 kinds of hormones IAA,GA3 and ABA,we used Xinjiang Zhipi almond to study the dynamic change of three kinds of endogenous hormones in new shoots, fruiting branch sections, young fruits and fruit stalks of the normal fruits and fruits which was about to fall. The fruit setting rate was also tested by applying these three hormones on different tissues,respectively. The results showed that： （1）The changing tendency of three kinds of en- dogenous hormones in different tissues were consistent with the growing of new shoots and physiological fruit drop. （2）During the physiological fruit drop, GA3 and IAA in the normal fruits was always greater than that of the fruits which was about to fall. The hormones in the fruit stalks of normal ones were also greater than that in fruit stalks of the dropping ones. Changes of ABA were just the opposite. （3）It was proven by the internal analysis and external applying of these hormones that high level of GAa and IAA, and low level of ABA in young fruits and their stalks were helpful to fruit set;Concentration ratio between endogenous hormones in new shoots and young fruits was an important factor for the regulation of physiological fruit drop in almond. High level of GA3 （new shoots ）/GA3 （young fruits）,IAA（new shoots）/IAA （young fruits） and low level of ABA （new shoots）/ABA（young fruits） would induce fruit drop, vice versa.