Studies On The Cutting Propagation Technique And Rooting Physiological Basis Of Machilus Breviflora

Machilus breviflora is a very promising prospect of economic forest and evergreen ornamental tree speciesin the Southern C hina.For a long time,mainly by seed reproduction,there is a serious variation of differentiation phenomenon,but the cutting propagation can better preserve the excellent characters of the female parent.In this paper,cutting propagation technology system of Machilus breviflorawas explored from the cutting medium,growth regulators,concentration and treatment time,using multiple comparison,range analysis and membership function evaluation method to judge the cutting effect;in addition,through the dynamic monitoring of 6 physiological indexes of the cuttings and using correlation analysis,the physiological characteristics of softwood cuttings during the rooting process were revealed.The aims were to improve the conservation and breeding efficiency of Machilus breviflora,and provide some technical support and theoretical basis for future development and utilization.The main results are as follows:(1)The cuttage rooting type of Machilus breviflora is the rooting type of callus,and the adventitious roots took longer to form,which belongs to the difficult rooting species.Machilus breviflora could be divided into 3 stages: Callus formation stage,adventitious root expression stage and adventitious root elongation stage.The ABT treatment group and the control group were the same as the first stage of callus formation,all of which were about 20 d after cutting,but the adventitious root emergence period of the former was about 15 d earlier than the latter.(2)There were significant influence in the callus formation,adventitious root formation stage,root morphology and rooting index of 5 different substrates in the cuttings of Machilus breviflora.Based on the membership function of comprehensive evaluation,yellow soil +river sand + perlite(1:1:1,V/V)mixed matrix has optimal performance,the rooting rate was 47.62%.The time of callus and adventitious root emergence was the earliest,and the number of adventitio us roots,adventitious root length and longest adventitious root length were the best in all the matrix treatments.(3)In orthogonal experiment,different types of growth regulators,concentration and treatment time had significant effects on the root morphological and rooting indexes.The comprehensive evaluation of membership function showed that the optimal treatment of cutting propagation was treatment 3(A1B3C3).That is,the use of the concentration of 800mg/L ABT,the treatment of cuttings for 30 minutes could make the best cutting effect,rooting rate of 48.89%.The primary and secondary levels of cutting rooting effect of Machilus breviflora were growth regulator type > treatment concentration > treatment time,that is,growth regulator type was the most important factor,and the rest were treatment concentration and time.(4)The content of soluble sugar and soluble protein had a significant positive correlation with the rooting rate of cuttings(P<0.01).The content of the two and the magnitude of the change in the cutting process would directly affect the cutting effect.The rooting rate had significantly positive correlation with the superoxide dismutase activity(P<0.05),extremely positively correlation with the content of chlorophyll a and chlorophyll(a+b)(P<0.01),negatively correlation with indoleacetic acid oxidase activity and malondialdehyde content.The growth regulator treatment increased superoxide dismutase activity,slowed down the decomposition of chlorophyll(a+b),decreased the indoleacetic acid oxidase activity and malondialdehyde content,increased the resistance to bad environment and the content of indole acetic acid,delay the senescence of cuttings,and then promoted rooting and raised the rooting rate.(5)There was a close correlation between the physiological indexes in the cutting process,soluble sugar had a significant positive correlation with soluble protein and chlorophyll(a+b)(P<0.05),extremely significant positive correlation with superoxide dismutase and chlorophyll a(P<0.01),and a significant negative correlation with malondialdehyde.Superoxide dismutase had a significant negative correlation with malondialdehyde,a significant positive correlation with chlorophyll(a+b)and chlorophyll a.It was shown that the physiological indexes do not play a single role in the rooting of the cuttings,but they affect each other in the rooting process of Machilus breviflora.