Effects Of Low Temperature Stress On Physiological, Biochemical And Photosynthetic Characteristics Of Cabbage Seedlings

Cabbage(Brassica oleracea L.),a cruciferous plant,a mild and cool climate.In the cold winter,outdoor low temperature or even subzero temperature is often encountered,which limits the growth and development of cabbage.Cabbage varieties with strong cold tolerance are needed in production,and the premise of breeding cold-tolerant cabbage varieties is to provide excellent low temperature resistant materials.Therefore,exploring the cold-resistant mechanism of cabbage seedlings at different low temperatures is important for the wintering of cabbage.In this experiment,the seedlings of low temperature resistant variety "BoZ-17" and cold sensitive variety "BoY-17" were used as experimental materials to study the changes of physiological and biochemical characteristics and photosynthetic characteristics of cabbage seedlings under different low temperatures.The main results are as follows:1)Under low temperature stress,the relative conductivity of two varieties of cabbage seedlings increased with the decrease of temperature,and the change range of "BoY-17" was larger than "BoZ-17".2)With the decrease of temperature,there is no significant difference in the MDA content of "BoZ-17",and the MDA content of "BoY-17" is slightly increased;the MDA content of "BoZ-17" at low temperature is significantly lower than "BoY-17".3)There was no significant difference in protein content between the two varieties of cabbage seedlings and between varieties under low temperature stress.4)The synergistic effect between SOD,POD and CAT under low temperature stress,the effect of POD is later than SOD,and the enzyme activity level of "BoZ-17"is higher than "BoY-17" overall.5)Low temperatures can reduce photosynthesis in plants.The lower the temperature,the lower the photosynthetic rate and the weaker the respiration.