吲哚丁酸对桃砧木GF677不定根形成过程中生理生化指标的影响

Effects of 3-Indole Butyric Acid(IBA)on the Physiological and Biochemical Indexes of Adventitious Root Formation in Peach Rootstock GF677

【目的】明确激素诱导对无性系砧木不定根形成的影响。【方法】以清水为对照组(CK),分别用200、500、800和1100 mg/L吲哚丁酸(3-indole butyric acid,IBA)处理桃无性系砧木GF677的1年生插穗基部,研究其扦插生根过程中生理生化指标的变化。【结果】经200 mg/L IBA(T_(1))诱导的根系效果指数显著大于其他处理(P<0.05),生根率达94.63%。处理组插穗全氮(total nitrogen,TN)、全磷(total phosphorus,TP)和全钾(total potassium,TK)含量均呈下降趋势,降幅均大于CK;插穗多酚氧化酶(polyphenol oxidase,PPO)、过氧化物酶(peroxidase,POD)和吲哚乙酸氧化酶(indoleacetic acid oxidase,IAAO)活性先增强后减弱,吲哚乙酸(indole acetic acid,IAA)含量先升高后降低,上述4个指标均在不定根形成期(21 d)出现峰值,且变幅最大为T_1处理;处理组细胞分裂素(cytokinin,CTK)含量逐渐下降,且以T_(1)处理降幅最大;处理组乙烯(ethylene,ETH)含量缓慢升高,且以T_(1)处理变幅最小。相关性分析显示:生根率与插穗TN、TP、TK和CTK含量极显著负相关(P<0.01),与IAA含量、IAAO活性和PPO活性极显著正相关(P<0.01)。【结论】T_1处理可显著提高插穗酶活性并加速IAA合成,说明200 mg/L IBA能更好地调节氧化酶和内源激素水平,促进不定根形成。

[Purpose]To clarify the effects of hormone induction on the formation of adventitious root of clonal rootstocks.[Methods]Clear water was used as the control(CK),the bases of 1-year-old spikes of peach clonal rootstock GF677 were treated with 200,500,800 and 1100 mg/L 3-indole butyric acid(IBA),the physiological and biochemical indexes changes during the rooting process of its cuttings were studied.[Results]The root induction effect index of 200 mg/L IBA treatment(T_(1))was significantly higher than that of other treatments(P<0.05),the rooting rate reached 94.63%.The contents of total nitrogen(TP),total phosphorus(TP),and total potassium(TK)of cuttings showed a downward trend,with a decrease greater than that of CK.The activities of polyphenol oxidase(PPO),peroxidase(POD),and indoleacetic acid oxidase(IAAO),and the content of indole acetic acid(IAA)in cuttings increased first and then decreased,and the peak value appeared at the formation stage of adventitious root(21 days),with the maximum amplitude of T_(1) treatment.The content of cytokinin(CTK)in the treatment groups gradually decreased,with T_(1) treatment showing the largest decrease.The content of ethylene(ETH)showed a slow increase,and the T_(1) treatment showed the smallest vari-ation.Correlation analysis results showed that the rooting rate was extremely significantly negatively correlated with the contents of TN,TP,TK,and CTK(P<0.01),and extremely significantly posit-ively correlated with IAA content,and the activities of IAAO and PPO(P<0.01).[Conclusion]T_(1) treatment increases the enzyme activity of cuttings significantly,and accelerates the synthesis of IAA.It indicates that the exogenous hormone 200 mg/L IBA can better regulate its oxidase and endogen-ous hormone levels and promote adventitious root formation.