Studies On The Softwood Cutting Propagation Technique And Rooting Mechanism Of Euonymus Alatus (Thunb.) Sieb.

One-year-old semi-lignified Euonymus alatus(Thunb.)Sieb branches was taken as test material,the cuttings were treated with the rooting accelerator,include ABTl#?IBA?NAA and IBA+NAA,and set the concentration gradient to 200 mg·L-1?500 mg·L-1?1000 mg·L-1.In order to study the different concentration and processing time effect on cutting propagation of Euonymus alatus(Thunb.)Sieb,selected the low concentration as 200 mg·L-1 soaked stem cuttings with 2h?4h?6h,and the high concentration as 500 mg·L-1 1000 mg·L-1 treated stem cuttings with 10s?30s?60s,with water as the control group.In order to study the change of endogenous hormones and endogenous nutrient content during the rooting process of the Euonymus alatus(Thunb.)Sieb,stem cuttings were treated with IBA and IBA+NAA concentrations both in 500 mg·L-1 solution in 10s,with water as the control group.Meanwhile observed the anatomical structure of Euonymus alatus(Thunb.)Sieb rooting process,aimed at exploring the Euonymus alatus(Thunb.)Sieb cuttings propagation and rooting mechanism.The main findings are as follows:1.The mixed hormone IBA+NAA was the best endogenous hormone in the four,all the rooting rate was higher than that of the control group,which reached 80.0%?96.7%,and considered as the most suitable type of hormone.The worst hormone for rooting was NAA,with all rooting rate lower than the control group.In the low concentration treatment,the best rooting effect was IBA 200 mg·L-1 treated with 4 hours,which the rooting rate reached 88.3%?the average root length of rooting was 3.7cm?more than 2cm rooting number was 35.0?the root effect index was 6.48.While in the high concentration treatment,the best program were IBA+NAA 500 mg·L-1 treated with 30s and IBA+NAA 1000 mg·L-1 treated with 60s,the indicators as follows:the rooting rate reached 90.0%?91.7%;the average root length of rooting was 3.3cm?2.9cm;more than 2cm rooting number was 24.0?25.7;the root effect index was 3.96?3.73.As a suggestion,use IBA 200 mg L-1 treated with 4h?IBA+NAA 500 mg·L-1 treated with 30s and IBA+NAA 1000 mg·L-1 treated with 60s for Euonymus alatus(Thunb.)Sieb cutting propagation.2.The change of endogenous hormones during the rooting process:IAA increased during the induction and expression phase of adventitious roots,however,a sharp decreased while adventitious roots elongation,high concentration of IAA can promote the formation of adventitious roots.ABA decreased significantly in the period of adventitious roots induction,and the increased during the expression phase of adventitious roots.The valley of ABA coincided with the peak time of adventitious roots formation,thus,ABA has an inhibitory effect on the formation of adventitious roots.GA3 significantly decreased in the expression stage of adventitious roots,after adventitious roots highlighted the epidermis,GA3 content showed an upward trend,as a result,GA3 can promote the elongation of adventitious roots.Before adventitious roots highlighted the epidermis,ZR floated at lower concentrations,and significantly increased during the period of adventitious roots highlighted the epidermis,but sharply decreased while adventitious roots elongation,it is visible that the low concentration ZR is more favorable for the elongation of adventitious roots.Besides,the ratio of IAA/ABA and GA3/ABA are positively correlated with rooting rate,while the ratio of ZR/ABA is positively correlated with rooting effect.3.The change of endogenous nutrient content during the rooting process:starch tended to decrease at the beginning of cutting,in the expression of adventitious roots stage increased significantly,and stayed at a high level of concentration tends to be stable in the adventitious roots elongation stage.Soluble sugar and soluble protein content were generally showing a decline?rise?decline in the trend.Among them,soluble sugar decreased at the beginning of cutting,increased during the induction period of root primordium,and then decreased in the adventitious roots expression and elongation stage.Except that,it found peak and valley of the critical point of soluble protein and soluble sugar were roughly identical.The nitrogen content increased rapidly at the beginning of cutting,and then decreased during the expression phase of adventitious roots,while the adventitious roots elongation stage,the nitrogen content slowly accumulated and became steady.The ratio of C/N is positively correlated with rooting effect.4.There was no root primordium in anatomical structure of Euonymus alatus cuttings,it belongs to the induced roots type species.Adventitious roots formation was mainly based on epidermis rooting of softwood cuttings for Euonymus alatus(Thunb.)Sieb,and a small part of callus rooting,it belongs to mixed rooting type.The primordial somatic cells of the roots were produced in the vicinity of the formation layer near the xylem or the formation layer.However,the differentiation of IBA 500 mg·L-1 was not obvious.When treated with IBA+NAA 500 mg·L-1 the cell differentiated dramatically near the formation layer,and root primordia occurred at more sites.After cutting 6 days,the base incision significantly expanded,and the cracked phenomenon was observed at the base of phellem wing and phloem of Euonymus alatus(Thunb.)Sieb cuttings.The root primordia cells gradually developed into adventitious roots after 6?12d.Around 18d most of the cutiings developed complete root.