Research On Cold-tolerance Of Six Perennial Flowers Species In Taian

Perennial flowers that can live many years without a few years to plant woody stems,growing strong, strong adaptability, economical and convenient to use, once planted can enjoy for years, viewing period varies, may anniversary selection, is the street, industrial and mining areas, poor soils to beautify the fine flowers. With the rapid urban greening, perennial flower garden workers more and more widely used, because of perennial flowers can beautify cleaning up the environment, and enhance people’s life goals, to improve the quality of urban green landscape and environment of great benefit, it has become the city an important part of the ecological improvement. Six perennial flowers species including Phlox.paniculata,Sedum.spectabile, Iris.pseudocorus, Aster.novi-belgii, Veronica spicata, Kniphofia.uvaria were used as test materials. Lethal temperature 50(LT50) was calculated with logistic formula through determining electrolyte conductivity. Influences of cold stress on osmotic regulation substances including soluble sugar contents, soluble protein contents, proline contents, POD activity were investigated. By using fuzzy mathematics method, the cold tolerance of six perennial flowers species was evaluated. The main conclusions are as follows:1. Phlox.paniculata, Veronica spicata, Kniphofia.uvaria early infancy, usually in early April, the Aster.novi-belgii bud late, usually in late April; Iris.pseudocorus bloom early, as early May, Phlox.paniculata, Veronica spicata, Kniphofia.uvaria bloom in early June, the Aster.novi-belgii blossom latest, for early September; a longer period Kniphofia.uvaria,Iris.pseudocorus, Aster.novi-belgii, according to a shorter flowering; Iris.pseudocorus wither earlier Kniphofia.uvaria wither late.2. With cold stress increased, electrolyte conductivity presents a regular trend with the "S" shaped curve. lethal temperature 50( LT50) was calculated with logistic formula through determining electrolyte leakage rate. Lethal temperature 50( LT50) of Phlox.paniculata, Sedum.spectabile, Iris.pseudocorus, Aster.novi-belgii, Veronica spicata,Kniphofia.uvaria is respectively-30.38℃、-29.88℃、-28.11℃、-29.43℃、-24.73℃、-24.51℃.From the level of lethal temperature 50(LT50), the cold tolerance of six perennial flowers species was evaluated as Phlox.paniculata, Sedum.spectabile, Aster.novi-belgii,Iris.pseudocorus,Veronica spicata, Kniphofia.uvaria3. The study found that electrolyte conductivity was negatively correlated with cold tolerance of six perennial flowers species. POD activity,soluble sugar contents, soluble protein contents and proline contents were positively correlated with cold tolerance of six perennial flowers species. The study found that the physiological condition of the plants isinfluenced by environmental factors and their own factors, the change is very complicated,and various physiological indicators should be combined in order to more accurately evaluate the cold tolerance level of plants. During feasibility analysis on introduction and promotion to the higher latitudes of perennial flowers species various indicators should also need a comprehensive consideration.4. Analysis of variance showed the difference was significant during electrolyte conductivity, soluble sugar contents, soluble protein contents, proline contents, POD activity in different perennial flowers species. The difference was particularly significant during electrolyte conductivity, soluble sugar contents, soluble protein contents, proline contents,POD activity in different low temperature processing.5. By using fuzzy mathematics method, the cold tolerance of six perennial flowers species was evaluated as Phlox.paniculata, Sedum.spectabile, Aster.novi-belgii,Iris.pseudocorus,Veronica spicata, Kniphofia.uvaria.