Study On Restricting Conservation Technique Of Hosta Plantaginea

Hosta plants have unique ornamental value and high medicinal chemical value.Wild hosta plants are vulnerable to pathogens and viruses.It is particularly important to study the conservation of hosta germplasm resources based on the long-term purpose of variety cultivation and resource utilization.In this experiment,the sterile seedlings of Hosta plantaginea were used as the main materials,and orthogonal design was used to study the effects of different concentrations of osmotic compounds and growth inhibitors,various conservation schemes were developed.The optimal medium-term conservation scheme for Hosta plantaginea was optimized by comparing the changes of survival percentage,phenotype,content of physiological substance and SSR molecular level,and study the conservation mechanism,The main results were as follows:1.Based on a six-month survival percentage,the three schemes with the highest survival percentage were selected.The three schemes were scheme 1(Sucrose 50g/L+Mannitol 10g/L+ABA 0.5 mg/L+CCC 10mg/L),scheme 2(Sucrose 50g/L+Mannitol 20g/L+ABA lmg/L+CCC 20mg/L)and scheme 5(Sucrose 70g/L+Mannitol 20g/L+ABA 0.5 mg/L+CCC 30mg/L).,After conservation in these three schemes for 12 months,the survival percentages were all 100%,and there was no difference in SSR molecular level compared with the control.The roundness and plant height of the Hosta plantaginea preserved in Scheme 1 could not be restored to the normal state after restoration culture.The antioxidant enzyme activity of the Hosta plantaginea preserved in Scheme 5 was lower,and the content of MDA was higher in the later period of conservation.This might indicate that the material in the conservation process has been subjected to physiological stress,thus the best conservation scheme was Scheme 2.At the same time,the optimal scheme was formulated as follows:Sucrose 50 g/L+Mannitol 20g/L+ABA 1 mg/L+CCC 40 mg/L.After 6 months storage in optimal scheme,the survival percentage of Hosta plantaginea was 100%,and there was no difference in phenotype,molecular level compared with control.In the optimized scheme,Hosta ensata?Hosta fortunei 'Gold Standard' and Hosta undulata 'France' could all achieve a survival percentage of 100%,and the SSR molecular level was no different from that of the control group after 6 months conservation.2.The phenotypic changes of Hosta plantaginea in different conservation schemes were observed.The results showed that the growth restricting conservation scheme could prolong the subculture time by dwarfing the plants.The medium-term conservation process of Hosta plantaginea could be divided into two stages,the first stage was plant dwarfing stage and the second was slow growth stage.In the first stage,from the first month to the eighth month,the plants were gradually dwarfed,the leaves turned yellow,the overall color of the leaves became light,and the roots were shortened obviously.After entering the second stage,the plants had adapted to the conservation environment and the leaves gradually became darker,plant height increased slowly.3.The SOD?POD and CAT enzyme activities of plants preserved in restricting schemes were all higher than that of the control group,and MDA content was lower than that of the control group.These indicated that each conservation scheme could increase the activity of antioxidant enzymes and decrease the degree of membrane lipid oxidation.In additon,the better conservation scheme could also prolong the activity time of antioxidant enzyme of Hosta plantaginea,so as to delay the senescence of the plants and prolong the conservation time of the Hosta plantaginea.