Cutting Propagation Techniques And Rooting Mechanism Of Cyclocarya Paliurus(Batal.)Iljinskaja

Cyclocarya paliurus is a well-known multiple functioning tree species that is native toChina. In order to deal with several challenges in asexual reproduction faced in practice, cuttingpropagation techniques were evaluated with respect to times and positions of cutting collection,pretreatments of tannin removal from cuttings, hormone treatments, cutting storage treatmentswith moisture sand, cutting media, as well as several environmental and physical factors.The physiology characteristics of cuttings during adventitious rooting process were alsoinvestigated. Results from this study would provide technical and theoretical basis for cuttingpropagation of C. paliurus. The main findings are summarized as follows:1. Exogenous hormone treatment significantly increased rooting rates of C. paliurus. Forhardwood cuttings, treating cuttings for3hours with hormone combination of IBA（100mg/L）+ABT-1（300mg/L）+GGR-6（300mg/L）resulted in the highest rooting rate, which was up to34.4%. Hormone treatments with ultrasonic effectively improved rooting rate of the hardwoodcuttings. Treating with6-BA led to improved callus rate but not rooting rate of hardwood cuttings.Hormone treatment to un-rooting hardwood cuttings had limited effect on induction of rootformation. Acetone pretreatment effectively reduced tannin content in the cuttings andinhibited PPO activity, which resulted in increased rooting rates.2. Different matrix moisture and atmospheric humidity had marked effect on rooting rates ofC. paliurus Cuttings.70%air humidity and30%soil moisture for Perlite+Turfy soil（1:1）wereoptimal for rooting of softwood cottage. Matrix types significantly affected rooting rate, but theresponses differed with respect to various hormone treatments. The obtained results indicatedthat cuttings treated with medium containing Perlite+Vermiculite （1:1） mixed withABT-1+GGR-6（300+300mg/L）resulted in the highest rooting rate, which was up to32.2%.3. For softwood cuttings, there were fewer calluses in the cuttings and rooting was donemostly through bark enlargement and cracking. However, hardwood cuttings had more callus,and thus, rooting was mainly achieved from the callus induced. Generally, rooting rate ofhardwood cuttings was slightly lower than that of softwood cuttings. For the upper section ofbranches in summer season, treatment with hormone combination of ABT-1+GGR-6（300+300mg/L resulted in the highest rooting rate of up to44.4%. For the base part of branches in winter,the same treatment resulted in rooting rate of up to36.7%. The obtained results suggested that theupper sections of branches are better cuttings in summer season, while base part of branches arebetter cuttings in winter.4. During rooting process of C. paliurus cuttings, considerable amount of solublesugar, starch, and protein were consumed. The activities of SOD, POD and PPO were closelyrelated to rooting rates. High activity of SOD and POD favored bark enlargement of cuttings,while high activity of SOD and PPO enhanced resistance of cuttings. Hormone treatments resulted in increased enzyme activities, and led to changes in enzymes activities to promoterooting of cuttings. The dynamics of internal hormone contents in C. paliurus cuttings, to certainextent, reflected rooting ability. Matrix heating and hormone treatments of cuttingsaffected their content of endogenous hormones produced during rooting process, and thus,affected rooting. Relatively consistent content of total nitrogen was in favor of root formation.