Studies On Rooting Mechanism And Cutting Propagation Technique Of Corylus

Rooting mechanism and cutting propagation technique of Corylus such as herterophylla, hybrid hazelnut and avellana were studied with different auxins and concentrations on soft and hardwood cuttings under different media. The research including: Rooting capacities(rooting rate, root number, root length) of soft and hardwood cuttings; anatomical proerty of adventitious roots using paraffin section technology; dynamic changes of rooting-related physiological biochemical indexes(oxidases, nutriments, endogenesis hormones) and annual growth rules of cuttage seedlings. The aim of studies is to provide scientific basis and technological guide for Corylus propagation.Most adventitious roots of Corylus cuttings(hard or softwood cuttings) came from stimulated callus. Both stimulated and free callus could root. The adventitious roots developmental process can be divided into 3 distinct phases, i.e., induction, expression and elongation.The anatomical observation on softwood cuttings showed that the rooting type of avellana originated from callus. There was no induced root primordium in cuttings. The induced root primorbium which originated from the parenchyma cell of cambium between xylem and phloem developed into adventitious roots.The activities of POD, PPO and IAAO appeared tendency of"enhancing-descending". The activity of POD had two peaks during rooting process. The activity of POD increased up during induction and expression phase and declined at the elongation phase. The activities of PPO and IAAO increased up during induction and declined at the expression elongation phase. IBA could change the activities of the oxidases and promoted rooting process.The contents of soluble sugar, total N and the ratio of C/N appeared different change laws. The content of soluble sugar decreased gradually during hardwood cutting rooting. The content of soluble sugar in cuttings treated by IBA had significant differences in contrast with control. The higher content of soluble sugar and ratio of C/N of hardwood cuttings was favorable to root. On the contrary, the lower ratio of C/N was benefit to softwood cuttings root. The content of soluble sugar in cuttings by IBA treatment is lower than that of control. So the theory of C/N was inapplicabe in Corylus softwood cutting.IAA, ABA and GA3 had different change rules during rooting process. The content of IAA in hardwood cutting had significant differences in contrast with that of softwood cutting. The content of IAA in both hard and softwood declined at the expression and elongation phase. Both ABA and GA3 restrained cutting rooting. The changes of IAA content were contrary to ABA. The ratio of IAA and ABA can be as a scale estimating softwood cutting rooting capacities.The media can affect cutting rooting. The results showed that only mixed media could enhance the percentage of hardwood cuttings rooting by IBA treatment in media experiment with river sand, perlite and mixed media. The hardwood cuttings of avellana could not root under river sand or perlite media. Rooting percentage of cutting by 200mg·kg-1IBA treatment under mixed media reached 60%. The rooting rate of softwood cutting in both river sand and perlite only reached 13.3% and 9.7%, and 42.5% in mixed media.The kinds and concentrations of auxin affected rooting. Auxin treatment could increase rooting percentage, but the rooting rate was below 50% and control could not root. IBA had the most significant effect on rooting rate of cuttings in avellana thanα-NAA and ABT1, and the rooting rate could reach 56.7% by 200mg·kg-1IBA treatment.Different Corylus varieties had different reaction to IBA treatment. The rooting rate reached the maximum 20% by 500mg·kg-1IBA treatment in Heterophylla, and control could not root. The rooting rate reached the maximum 48.3% by 100 or 500mg·kg-1IBA treatment in hybrid hazelnut, and the rooting percentage of cutting only reached 20% in control. Avellana reached the maximum percentage of 73.3% by 400mg·kg-1IBA treatment, and control only reached 8.3%. Heterophylla had the worst results among three varieties. Hybrid hazelnut and Avellana can be propagated by cutting.The rooting percentage of cutting in different ends(upper and under end in morphology) and diameters(0.5~1.0cm and 1.0~1.5cm) by IBA treatment had not significant difference in Avellana. The rooting rate reached 8.3% and 18.3% in leptos and stout stress espectively, and the rooting rate reached 10% and 8.3% in upper and under end in morphology. Diameters and ends were not primary influenced factors.Height growth curve of Avellana cutting seedling could be fitted into'S'curve. Net height growth appeared tendency of"slow-fast-slow-stopping". The growth of height and ground diameter reached the maximum on July and August. The cutting seedling should be managed intensively during June to August.