不同扦插日期美人梅嫩枝扦插生根特性及生理生化

Effects of different cutting date on softwood-cutting rooting and related physiological and biochemical changes during rooting of Prunus mume Meiren

从美人梅半木质化茎段的中上部选取插穗,在2015年5月和8月采用2 500 mg·L^-1IBA处理插穗,研究不同扦插日期美人梅生根特性和生根指标差异及扦插后不同时期插穗皮部可溶性糖、可溶性蛋白、淀粉含量和过氧化物酶（POD）、多酚氧化酶（PPO）、吲哚乙酸氧化酶（IAAO）活性的变化。结果表明,（1）不同季节美人梅嫩枝扦插生根过程均可分为根的诱导期（0-10 d）、表达期（10-30 d）和伸长期（30-40 d）3个阶段。（2）IBA处理可显著提高插穗生根率。扦插后,诱导期淀粉与可溶性糖含量上升,可溶性蛋白含量降低,POD活性升高,IAAO活性处于较低水平,有利于诱导根原基的发育。表达期,IBA处理能加速淀粉的分解,使POD活性先下降后升高,IAAO活性持续升高,有利于不定根的表达。伸长期,IBA处理能使可溶性蛋白含量继续增加,POD活性下降,有利于不定根的伸长。（3）扦插时间不同,其内源物质含量及变化存在差异。5月份插穗内可溶性糖含量及3种氧化酶活性在表达期均高于8月份;整个生根过程中,5月份插穗与8月份插穗的PPO活性变化呈现相反规律。该研究以5月份IBA处理插穗生根效果较好,可为北方抗寒梅花嫩枝扦插生产提供技术支持和理论依据。

The objective was to study the effects of different cutting date on softwood-cutting rooting and related physiological and biochemical changes during rooting of Prunus mume Meiren. The upper and middle parts of semi-hard wood stems were collected and treated with IBA at a concentration of 2 500 mg·L-1with water dipping as control in May and August,respectively. Contents of soluble sugar,starch,soluble protein and activities of peroxidase（ POD）,polyphenol oxidase（ PPO）,indoleacetic acid oxida-se（ IAAO） in phloem at various rooting phase were measured. The results showed as follows：（ 1） In different seasons,the adventitious root displayed three distinct pha-ses： induction（ 0-10 d）,expression（ 10-30 d） and elongation（ 30-40 d）.（ 2） IBA treatment had an obvious effect on accelerating rooting of cutting. During induction phase,the contents of soluble sugar and starch increased while the soluble protein content declined; POD activity rose and IAAO activity was in a lower level,which was good for growth of root induction. During expression phase,IBA treating could accelerate decomposition of starch,and POD activity increased after slightly decreased,and the continuous elevation of IAAO activity could benefit rooting expression. During elongation stage,POD activity decreased and IBA could make soluble protein content keeping ascending.（ 3） During the rooting process,PPO activity changed on the contrary in May and August,at the same time the soluble sugar content and oxidases activity in May were higher than those in August during expression phase. The cuttings treated with IBA in May rooted better,which could provide technical support and theoretical basis for the cutting propagation of cold-resistance Prunus mume.