Study On Rapid Propagation System And Physiological Responses Of Stress Of Haplocladium Microphyllum

Haplocladium microphyllum was served as the experimental material in this paper, whosemicropropagation system was established by means of aggregate culture, nutrient solution culture,tissue culture. The physiological stress responses of H. microphyllum which were on drought stressand heat stress was researched, and the means of its garden application were surveyed and summed up.The purpose of the study was to provide data support and theory evidences of large-scale cultivationand garden promotion and application in the future. The main conclusions were obtained as follows.1. To establish the micropropagation system of H. microphyllum: In the substrate culture, fourkinds of light conditions（full illumination, shading30%,50%,70%）and four kinds of matrices（perlite, vermiculite, peat, mixed media）were setted to research the effect of the growth of it. Theresult showed the effect of light and substrate had a highly significant difference on the coverage of H.microphyllum (P<0.01), the conditions of shading50%and peat matrix was most conducive to thegrowth of H. microphyllum.In nutrient solution culture which was based on the substrate culture, the four nutrient solutionsof Benecke, modified Knop, Hogland and MS were researched to the effect of the growth of H.microphyllum. The result showed that the Benecke nutrient solution is most suitable for the cultivationof H. microphyllum, followed by modified Knop, Hogland, and MS nutrient solution worst. InBenecke nutrient solution, the coverage of H. microphyllum reached45.53%, branch length was3.72cm, branch number was54.13, fresh weight and dry weight respectively increased2.45times and3.69times after28days.In tissue culture of H. microphyllum, the callus induction and proliferation experiments werefocused on. By the method of the orthogonal experiment, the callus was induced on MS mediumsupplemented with various concentrations of6-BA，KT and2,4-D, callus proliferation also wasresearched on three kinds of carbohydrate sources of sucrose, glucose, fructose and6-BA. The resultsshowed that the best treatment in terms of callus induction was1mg/L KT and1mg/L6-BA. The besttreatment to callus proliferation was1mg/L6-BA and15g/L glucose.2. Relative membrane permeability, ability of osmo-regulation and changes of protectiveenzymes activities were studied in H. microphyllum under the full daylight and three different shadingof30%,50%and70%during drought stress and rehydration process in this study. Results showed that: Under drought stress, the chlorophyll content, the relative water content of substrate and tissueshowed a decreasing trend, while the relative conductivity and MDA content were on the contrary.The content of soluble sugar and free protein, the content of free proline, SOD activity, CAT activityand POD activity increased firstly and then decreased. The relative water content and chlorophyllcontent showed an opposite tendency on the rehydrateion phase. The relative conductivity, the contentof soluble sugar, free protein and free proline, SOD activity, CAT activity and POD activity all wentup again within a narrow range and then decreased, but SOD, CAT and POD still kept higher activity,while the content of MDA decreased gradually. Most of the tested indices after rehydration couldrecover to the levels of before drought stress. Based on these, it can be concluded that H.microphyllum has the typical characteristic of resurrection plant, possess a strong ability on anti-dryduring the variation of moisture content.3. The dynamic variation of H. microphyllum gametophyte the relative conductivity, MDA, SOD,POD, soluble protein and chlorophyll were determined using artificial controlled temperature at25℃（comparison）,35℃,40℃,45℃. The results showed: The relative conductivity, the content of MDAbecame increased as the increasing of the temperature, while soluble protein, SOD and POD activityfirstly increased and then became lower. Chlorophyll content firstly became lower as the increasing ofthe temperature. It is obvious that H. microphyllum gametophyte was found in possession of a certaindegree of heat resistance.4. Owing to the high ornamental value of H. microphyllum, it can be used as in the garden, greenroofs, the special garden of moss, bonsai, home gardening and so on. The results of the study willprovide basic information for the garden application of the wild ornamental bryophytes resources.