【摘要】 【目的】揭示赤霉素对桃成花的影响及其可能的作用机制。【方法】在桃花诱导期叶面喷施100mg·L-1GA3,运用解剖学、免疫组织化学及半定量RT-PCR方法,研究‘八月脆’桃花芽分化过程中顶端分生组织赤霉素的原位分布及成花关键基因表达变化。【结果】‘八月脆’桃在7月10日前处于成花诱导期(北京);成花诱导期叶面喷施100mg·L-1GA3显著抑制了桃花诱导及进一步的正常分化,处理后成花率仅为11.67%;顶端分生组织中GA1的分布随花芽分化进程而变化,6月13日-7月25日,花芽中GA1主要分布在芽基部的维管组织中,顶端分生组织中没有检测到信号。GA3处理后,GA1的分布在6月13日-7月3日与正常花芽相同,在7月13日顶端分生组织中检测到了GA1信号,且芽基部维管组织中的GA1信号增强,但至7月25日顶端分生组织和芽基部维管组织中的GA1信号明显减弱;GA3处理后,芽中PpLEAFY及MADS6基因仅在10月10日低量表达,其它时期几乎检测不到。【结论】在北京,‘八月脆’桃成花诱导期在7月10日之前;成花诱导期100mg·L-1GA3处理能显著抑制花诱导和进一步正常分化;赤霉素家族中GA1类在桃成花过程中起抑制作用,并且具有一定的时期性;GA3处理抑制了成花关键基因PpLEAFY及MADS6的正常表达。更多还原

【Abstract】 【Objective】 This experiment was conducted to study the effect of gibberellin and its possible mechanism on flower formation of peach. 【Method】 At the stage of flower induction, 100 mg·L-1 of GA3 was sprayed on the leaves of peach [Prunus persica (L.) Batsch.] cv. Bayuecui. Using the methods of anatomy, immunohistochemistry and semi-quantization, the in situ distribution of GAS and the expression of the key genes involved in peach flower formation in the apical meristem were studied during the period of flowering differentiation. 【Result】 The stage of flowering induction of ‘Bayuecui’ peach in Beijing was before July 10. The flower induction and further differentiation of flower organs of peach were significantly inhibited by leaf-spraying of GA3 at the concentration of 100 mg·L-1 during its flower inducing stage. The flower rate was only 11.67% after treatment. The distribution of GA1 in the apical meristem changed along with the process of flower bud differentiation. From June 13 to July 25, the GA1 signal of the control was detected mainly in the vascular bundle at the base of the flower buds. Meanwhile no GA1 signal was detected in the apical meristem. After being treated by GA3, the distribution was similar to the control from June 13 to July 3. But on July 13, GA1 signal was detected in the apical meristem accompanied by an increase of GA1 signal in the vascular bundle at the base of flower buds. GA1 signal weakened significantly in both vascular bundle and apical meristem on July 25. The expression of gene PpLEAFY and gene MADS6 in flower buds could only be detected on October 10 in GA3 treatment. 【Conclusion】 The critical period of flower induction of ‘Bayuecui’ peach in Beijing was in early July, during which leaf-spraying with 100 mg·L-1 GA3 could inhibit the flower induction and the further differentiation of the flower bud effectively. GA1 in the gibberellin family was thesuppressors for flower induction in peach. Its effect was affected by the stages of flower bud differentiation. The expression of the key genes PpLEAFY and MADS6 involved in flower formation were inhibited by GA3 treatment.更多还原