Study On The Drought Tolerance And The Landscape Application Of Four Perennial Flowers

This study had chosen four perennial flowers as experiment material, which are Acanthus praecox、Begonia grandis ’Sweetheart’、Coreopsis lanceolata and Gaillardia pulchella’Island’. The research had measured and analyzed external forms and related physiological indexes of these plants under drought stress and seasonal dynamic changes, and put forward the corresponding suggestions on landscape application. Using analysis of variance, correlation analysis, principal factor analysis and comprehensive evaluation of subordinate function method on the determination results to discuss the adaptation mechanism of the four kinds of perennial root flowers, provide theoretical basis for future landscape application. The main results of the study are as follows:(1) The external observations of 4 perennial flowers ’appearances under drought stress indicated that:In the middle and late period of drought stress, plants ’growth were obviously inhibited, and the leaves were wilting, yellowing, accompanied by partial loss. Under drought stress, the external appearances of 4 plants revealed the drought resistance:Acanthus praecox> Begonia grandis ’Sweetheart’> Gaillardia pulchella ’Island’> Coreopsis lanceolata.(2) The effects on soil moisture content, leaf water content, chlorophyll, the relative electrical conductivity and MDA under drought stress indicated that:4 perennial flowers’soil and leaf water content decreased, and chlorophyll reduced, the relative electrical conductivity increased, MDA content increased with the drought pressure.(3) The influence of drought stress on plants ’protection enzyme activity indicated that:under drought stress the enzyme system showed very intense reaction. SOD activity of each plant showed a trend of increasing in the beginning stage, and reducing then. POD activity increased gradually, when medium-term went downward. As the drought degree aggravating, CAT activity of Acanthus praecox amd Coreopsis lanceolata fell slightly in the late stage, while Begonia grandis’Sweetheart’and Gaillardia pulchella ’Island’ increased gradually.(4) The influence of drought stress on plants ’osmotic regulation substances content indicated that: Under stress, free proline content of leaves increased slowly. The soluble sugar content of 4 plants tended to declining at the beginning, as the stress degree deepening, the content showed a trend of gradually recovering. Plants’soluble protein content under drought stress declined to some extent.(5) Research on 4 perennial flowers’ adaptation under drought stress, utilize membership function method to improve the physiological indexes of comprehensive evaluation. Results showed that: the drought tolerance of 4 perennial flowers followed by:Begonia grandis ’Sweetheart’> Acanthus praecox> Coreopsis lanceolata> Gaillardia pulchella ’Island’.(6) The study on 4 perennial flowers’ change of growing seasons in the open place indicated that: 4 perennial flowers’ flourishing ability in Fuzhou area were good, and adapted to the environment relatively well.