The Impact Of Cold Hardiness And Floral Color Under Low Temperature Stress On Floral Organs Of Early Spring Flowering Plants

With 10 kinds of early spring flowering plants of Baoding as materials, using The Artificial Climate Chamber which can accurately simulate the natural cooling process of night cream to measure the supercooling point of the petals at different developmental stages, and cream box with its low temperature, measurement of electrolyte leakage rate, combined with the Logistic equation, lethal temperature, browning rate statistics, which sort of their cold resistance; choose Amygdalus triloba Amygdalus davidiana Jasminum nudiflorum as the test material,a comparative study on antioxidant enzymes activities and proline content about 3 kinds of petals of flowering plants in early spring under low temperature stress; choose Amygdalus davidiana Rhododendron mucronulatum Jasminum nudiflorum as the test material, a comparative study on pigment content, color and related enzymes of 3 kinds of spring flowering plants at low temperature, provide the production of flowering plants cultivation and the theoretical basis for the use of resources.The results show that: with the development of 10 kinds of flowering plants in early spring, the supercooling point showed a rising trend from bud to bloom stage, electrolyte leakage showed flowering>early flowering>bud stage, indicating that with the development of 10 species of flowering plants in early spring cold tolerance is dwindling, cold order of performance for bud stage>the early flowering stage>flowering stage; the lower the supercooling point, the stronger cold resistance, integrated three developmental stages supercooling points in 10 kinds of early spring flowering plants, electrolyte leakage, lethal temperature (LT50), results showed that 10 species of flowering plants in early spring cold hardiness from low to high is Amygdalus triloba, Amygdalus persica, Forsythia viridissima, Amygdalus triloba f. multiplex, Chaenomeles speciosa, Magnolia denudata, Amygdalus davidiana, Forsythia suspensa, Rhododendron mucronulatum, Jasminum nudiflorum.The soluble protein, soluble sugar and proline content of Amygdalus triloba Amygdalus davidiana Jasminum nudiflorum petals basic first increased and then decreased under Low temperature treatments. The soluble protein content of Jasminum nudiflorum were higher than Amygdalus triloba and Amygdalus davidiana at different temperatures; Jasminum nudiflorum petals proline, soluble sugar content the lowest temperature peak; under low temperature the soluble protein, soluble sugar, prolinol of 3 kinds of flowering plants petals in early spring basic acid first increased and then decreased. with treatment temperature decreases, the production rate of O₂.-, Lipid peroxidation MDA levels of 3 kinds of early spring flowering plants showed a rising trend, the same temperature the production rate of O₂.- and MDA content expressed as Amygdalus triloba>Amygdalus davidiana >Jasminum nudiflorum; relative conductivity, MDA content and the relationship between oxygen free radical production rate close , showed significant or highly significant positive correlation.After low temperature treatment, the petals 3 kinds of early spring flowering plants brightness L * values showed a moderate decline, and the lower the temperature, the more obvious trends; as the temperature dropped, Rhododendron mucronulatum to the red color and blue, in direction to the blue color as main, Jasminum nudiflorum to green and yellow, in direction to the green color as main, the Amygdalus davidiana to red and blue, in direction to the red color as main; The anthocyanin content and PAL enzyme activity of Amygdalus davidiana was positively correlation, the flavonoid content and CHI enzyme activity of Rhododendron mucronulatum showed a positive correlation, no significant correlation about Jasminum nudiflorum.