The Study On Cutting Propagation Of Buddleja Officinalis And Its Physiological Response To NaCl Stress

Buddleja officinalis Maxim.is an evergreen shrub of Buddleja L.in Buddlejaceae,which has important ornamental value,ecological value and medicinal value.However,it is still in the wild state,which limits its production and application.In order to provide a large number of high-quality Buddleja officinalis in a short time,and to explore the feasibility of its popularization and application in salinized areas,we studied the cutting propagation technology and physiological changes in the process of cutting from the aspects of rooting agent types,concentration and treatment time,cutting matrix,cutting time,lignification degree and cutting thickness;and set six NaCl concentrations of 0 mmol/L,40 mmol/L,80 mmol/L,120 mmol/L,160 mmol/L,200 mmol/L,treated Buddleja officinalis for 30 days,to explore the changes of its morphological and physiological indexes.The main results are as follows:1.The results of cutting propagation technology of Buddleja officinalis showed that :(1)According to the type,concentration and treatment time of rooting agent,the cuttings soaked in IBA200mg/L for 1h had the best rooting effect,the rooting rate was84.45%,and the root effect index was 2.93.(2)From the matrix,perlite: vermiculite(1:1)should be selected as the cutting matrix.(3)From the time,the cutting should be carried out in September.(4)From the lignification degree of cuttings,softwood pruning should be selected as cuttings.(5)From the diameter of cuttings,it should be controlled at 3～4 mm.2.The results of physiological changes in the cutting process of Buddleja officinalis showed that :(1)The type of rooting was skin rooting.IBA treatment could improve the rooting effect and promote its early rooting.(2)IBA treatment can accelerate the synthesis of soluble sugar and soluble protein,and improve the growth and development of cuttings.(3)IBA can advance the activities of SOD,POD and CAT in cuttings earlier,which is beneficial to rooting.In order to discuss the feasibility of spreading and application of Buddleja officinalis in salinization area,we set six NaCl concentrations of 0 mmol/L,40 mmol/L,80 mmol/L,120 mmol/L,160 mmol/L,200 mmol/L,treated Buddleja officinalis for 30 days,to explore the changes of its morphological and physiological indexes.The main results are as follows:1.NaCl stress can inhibit the growth of Buddleja officinalis.2.With the increase of NaCl concentration and the extension of stress time,the relative water content of leaves decreased,the content of chlorophyll a,chlorophyll b and chlorophyll a + b decreased,and the relative conductivity increased.3.At the beginning of stress,proline is the main organic osmoregulation substance,and then with the extension of stress time,soluble sugar and soluble protein gradually play a major role in the process of osmoregulation.The ability of osmoregulation of Buddleja officinalis is limited to a certain extent.Long time and high concentration of NaCl treatment will make Buddleja officinalis lose this ability.After 30 days of stress,Buddleja officinalis could maintain the higher content of proline,soluble sugar and soluble protein in leaves under 80 mmol/L for osmoregulation.4.Buddleja officinalis can reduce the damage of peroxidation caused by NaCl stress by increasing the activities of SOD,POD and CAT.In the early stage of stress,the activities of SOD,POD and CAT increased with the increase of NaCl concentration,but with the extension of stress time,the activities of SOD,POD and CAT increased first and then decreased with the increase of NaCl concentration.After 30 days of stress,the activities of SOD,POD and CAT in the leaves of Buddleja officinalis were higher under80 mmol/L.In this paper,the cutting propagation technology,physiological changes in the process of cutting and physiological response to NaCl stress were studied.We found that the best rooting effect could be obtained by cutting in September,selecting tender cuttings with 3～4 mm in diameter,treating them with 200 mg/L IBA for 1h,and using perlite: vermiculite(1:1)as the substrate.IBA could accelerate the growth of each in the cuttings.Under long-term stress,Buddleja officinalis could grow well under the concentration of less than 80 mmol/L.