杂交榛不同枝段绿枝扦插生根特性及相关氧化酶活性变化

The Characteristics of Rooting and Change of Oxidases in Different Portions of Softwood Cuttings of Hybird Hazelnut

采用简单重复扦插试验,设置发育枝上、中、下段和萌蘖上段浸蘸1 500 mg.L-1IBA,清水处理为对照,3次重复,研究了杂交榛绿枝不同枝段生根特性和生根指标差异及扦插后不同时期、不同枝段皮部的过氧化物酶(POD)、多酚氧化酶(PPO)和吲哚乙酸氧化酶(IAAO)的活性变化。结果表明:杂交榛子绿枝扦插以表皮生根为主,不同枝段部位在生根时期和生根指标上存在差异;幼嫩的上段插穗从扦插至生根只需13 d,而中段和下段分别需要19、22 d;发育枝上、中、下段和萌蘖上段经1 500 mg.L-1IBA处理的生根率、根数、根长显著高于对照,发育枝上段生根最好,萌蘖上段、发育枝中段和下段生根能力依次降低。扦插后POD活性呈上升趋势,至第1根出现期达到最大(峰值),处理和对照间、不同枝段间在峰值处存在差异,发育枝上、中、下段POD活性在峰值处的大小与其扦插生根率呈极显著正相关;PPO活性在扦插生根过程中呈现一定的双峰特性,扦插时至愈伤形成期PPO活性有一个增高期,诱导期至第1根形成期PPO活性第2次快速提高,至第1根形成期PPO活性达到最达值,之后有所下降;IAAO在愈伤形成期和第1根形成期之间的表皮瘤状突起形成期(诱导期)达到最大。

The rooting parameters of shoot parts of hybrid hazelnut （ Corylus heterophylla × C. aveUana ＇ Dawei＇ ） were investigated, and the activities of IAA oxidase （ IAAO）, polyphenoloxidase （PPO） and peroxidase （POD） in phloem at various rooting phase in different shoot parts were measured, in a simple random replication experiment. The growing shoot were cut into three sections： top part, middle part and bottom part, then treated with IBA at a concentration of 1 500 mg·L^-1 with a water dipping as control. The root formation position was primarily at the phloem. Rooting timing of different shoot parts was different, younger terminal portions needed 13 d to form adventitious root, middle portions and basal portions needed 19 d and 22 d, respectively. The current season＇ s growth treated with IBA at a concentration of 1 500 mg·L^-1 rooted well, the rooting percentage, root numbers and the length of root were significantly greater than that of the control ones. The terminal portions trom the glowing shoot rooted best, while the rooting ability of suckers terminal portions, middle portions and basal portions from the growing shoot were in the order of greatness to smallness. After treatment arrangement, the activity of POD showed an increasing pattern, with a peak at the formation of the first regeneration root. Between the treatments and the controls, different shoot parts expressed the related peaks, and magnitude of peaks was significantly positive correlated with the rooting percentage. During the cutting duration, the activity of PPO showed a double peak pattern, with the first increase at the time from starting to callus formation, and the second one from the induction phase to the first regeneration root forming, and the lower. During rooting process, there were differences highest peak at root formation. Afterwards, the peak became between the different shoot parts, and between the treatments and the controls, the activity of PPO had a difference. The between the callus formation time and the first regeneration activity of IAAO reached to peak at the induction phase root formation.