Research On The Drought Stress Adaptability Of Six Species Of Spiraea L.

Most of Spiraea plants are beautiful deciduous flowering shrubs;they have rich species and high garden ornamentation and appliable values.These genus plants are also rich in genetic diversity,the drought-resistance and drought adaptive capacities are significant differences among various varieties.Study the physiological basis and the growth adaptation of Spiraea in drought conditions,could breeding outstand the good Spiraea species of drought-resistance,and gradually applied to the drought and semi-drought regions of the building of landscape architecture,thereby filled the urban landscape of flowering shrubs vacancies application,enriched urban landscape features and color change;Through its comprehensive evaluation system of research,also provide theoretical reference and practical support for the selection and application of woody plants in drought environment.This thesis based on the trial material of Spiraea thiehoearpa Nakai.,Spiraea fritschiana Schneid.,Spiraea salicifolia L.,Spiraea media Schmidt.,Spiraea×bumalda 'Gold Mound' and Spiraea×bumalda 'Gold Flame',which could applied in the Northeast area.Via the microscopic observation of their root,stem and leaf anatomical structures,study of seed germination characteristics by the method of PEG drought simulation,inspected physiological and biochemical characteristics of 6 species of Spiraea at seedling period with method of water controlling in pot and set up three gradient of drought stress and the corresponding water recovery process,and this experimental design which integrated by those three aspects explored drought adaptive changes of the 6 species of Spiraea;The thesis has analysised the relations of different indicators and drought adaptability of Spiraea using SAS Correlation Analysis and Grey Relational Analysis Method,also established the comprehensive evaluation indicators system;Use SAS significant analysis and subordinative function analysis method analysised the relevant data,comparison the different and differences in 6 species of Spiraea of the capacity to adapt to drought;Mainly come to the following conclusions:Used subordinative function analysis method to analysis and sort the drought adaptive capacity of 6 species of Spiraea:S.fritschiana＞S.salicifolia＞S.media＞Spiraea×bumatda cv.Goldflame＞S.thichocarpa＞Spiraea×bumatda cv.Goldmound.Used grey relational analysis method to analysis and sort the relational degree of different physiological and biochemical indicators of 6 species of Spiraea:LWP＞LRWC＞LSP＞Pnmax＞LCP＞myristic acid content＞activity of SOD＞myristic acid content＞free proline content＞conductance rate＞soluble protein content＞soluble sugar content＞MDA content＞AWC/OWC＞ABA content. Combined with root,stem and leaf anatomical structures,capacity of seed germination and physiological and biochemical indicators have high relational degree to drought adaptive capacity of 6 species of Spiraea,stablished the comprehensive evaluation indicators system of Spiraea by 27 indicators like LWP etc.This thesis systematically studied on adaptive changes and adaptivity of 6 species of Spiraea to drought in aspects of anatomical structure,seed germination capacity,water-retention capacity of leave,photoresponse curve,osmocoditioning material,moisture physiological indicators,plasma membrane permeability indicators,ABA content,changes and expression of adaptive protein under drought stress and so on.However these research methods are first time used to identify the drought ability of Spiraea plants.