Effects Of Seaweed Functional Substances On Growth And Physiology Of Chinese Flowering Cabbage Under Drought Stress

Drought is one of the natural disasters that have the greatest impact on the sustainable development of agriculture.Seasonal drought in South China is one of the limiting factors that restrict the growth of Chinese flowering cabbage.Under drought stress,seaweed and seaweed functional materials play an important role in plant growth and defense responses.However,the physiological mechanism of different seaweed functional substances in drought resistance is not clear.In this paper,we used the Chinese flowering cabbage as the research material,through the pot experiment,to study the effects of seaweed fertilizer with exogenous alginic acid,algae polyphenols,mannitol and betaine on the growth of Chinese flowering cabbage under the drought stress.In order to provide a theoretical basis for the identification of functional effects of different seaweed functional materials.The results of the study are as follows:1.With the intensification of drought severity,the chlorophyll content and relative water content of Chinese cabbage leaves showed a downward trend,and the contents of proline,soluble sugar and malondialdehyde increased,the degree of cell membrane peroxidation increased,and the membrane permeability increased.SOD,The activities of CAT and POD showed a trend of increasing first and then decreasing.Under drought stress,Compared with the control of equal nutrient fertilizer treatment,the dry weight of Chinese flowering cabbages treated with seaweed and add 1 times alginic acid increased by 20.98% and 98.43%.2.Under drought stress,compared with the control,the dry weight of Chinese flowering cabbage treated with 4 times brown algae polyphenols increased by 60.98%;the chlorophyll and relative water content of leaves increased by 26.46% and 14.36%,respectively;Soluble sugar and proline increased by 50.16% and 125.13% respectively;membrane permeability decreased by 20.94%;and SOD,CAT and POD activity peaked at the fourth day.3.Compared with the control of drought,the treatment of 4 times mannitol could significantly increase the dry weight,soluble sugar content,proline content and SOD activity,which increased by 83.72%,101.11%,61.55% and 162.42%,respectively.4.Compared with the control of drought treatment,the dry weight of the Chinese flowering cabbage treated with 50 times of betaine increased by 56.28%,and the soluble sugar,proline content,SOD,and CAT activity increased 45.07%,78.48%,83.06% and 74.98% respectively;Malondialdehyde content decreased by 36.97%.5.A comparative study of algae acid(1AA),brown algae polyphenols(4AP),mannitol(4AM)and betaine(50GB)on the growth of Chinese flowering cabbage showed that,the treatment of alginic acid,algae polyphenols,mannitol,and betaine all increased the biomass of Chinese flowering cabbage.The effects of various treatments on the yield increase of Chinese flowering cabbage under drought stress are better than those under normal conditions.Under the drought stress,compared with the control(CK1),the order of the yield increase was 1AA>4AP>4AM>50GB;Its effect on the increase of yield of cabbage was 31.25-37.92%,19.89-21.89%,18.13-20.87% and 12.33-17.22%,respectively.Taken together,under drought stress conditions,the treatment of alginic acid,brown algal polyphenols,mannitol,and betaine can promote the growth and enhance the drought resistance of Chinese flowering cabbage.