Effects Of Different Electrical Conductivity Levels Of Nutrient Solution On The Growth Of Endive

?Object?The effects of different EC nutrient solution on the growth,yield,quality,photosynthesis and intrinsic physiological indexes of the endive were studied.The aim of this study was to investigate the relationship between EC value of nutrient solution and growth of endive,In order to screen out the suitable level of nutrient solution for the growth of endive,and to provide the theoretical basis for the high quality and high yield of endive hydroponics.?Methods?In this experiment,endive was used as test materials,Experiment set up 6 nutrient solution conductivity level: 0.2 ms/cm,0.5 ms/cm,0.8 ms/cm,1 ms/cm?CK,South China Agricultural University B concentration of leafy vegetables?,1.2ms/cm,1.5ms/cm.Determine the different growth period of seedling endive leaf length,stem diameter,leaf area,leaf number,dry weight and fresh weight;The content and yield of soluble sugar,nitrate,Vc,soluble protein and flavonoids were determined at harvest time.The chlorophyll content,net photosynthetic rate,transpiration rate,stomatal conductance,intercellular CO2 concentration and water use efficiency were measured.The activities of superoxide dismutase,peroxidase,catalase,ascorbate peroxidase,Glutathione reductase,dehydroascorbate reductase,deuterated ascorbate reductase.The test data were analyzed by variance analysis.?Results?1.Low conductivity(E_0.2 and E_0.5)two treatment showed yellow leaves,slow growth,root browning symptoms in leaf length,stem diameter,leaf area,leaf number,dry weight and fresh weight were lower than other treatments,E_0.8,E_1.2,E_1.5 treated seedlings in endive leaf length,stem diameter,leaf area,leaf number,dry weight and fresh weight had no significant difference compared with the control,the growth is good,deep green leaves.2.The yield increased with the increase of nutrient solution conductivity,the yield of E_0.2 was the lowest,E_1.5 treatment had the highest yield,but with E_0.8,E_1.0?CK?andE_1.2 three treatments were no significant difference;E_1.0?CK?E_0.8 processing the quality indexes is better than that of E_0.2 and E_0.5 two treatments,high conductivity(E_1.2,E_1.5)some quality indexes had no significant difference compared with the control,but the nitrate content was significantly higher than that of control.3.From the analysis of related enzymes from antioxidant,two with moderate conductivity(E_0.8 and E_1.0)in SOD,POD,CAT,GR,DHAR,MDHAR activity were higher than that of E_0.2;two with moderate conductivity(E_0.8 and E_1.0)and two with high conductivity(E_1.2 and E_1.5)in transpiration.Net photosynthesis,stomatal conductance and water use efficiency were higher than the two nutrient solution oflow conductivity(E_0.2 and E_0.5).?Conclusion?The nutrient solution EC value too high or too low are not suitable for the growth of endive.Its growth and development caused by inhibition.Under stress and endive ROS accumulation,increased lipid peroxidation,thereby reducing the effective oleraceus of photosynthesis and the accumulation of organic matter,the formation of hydroponics endive quality and yield in the water was based on the normal and effective physiological activities of the plant.From the whole point of view,the growth index of the appearance and intrinsic physiological indexes and the changes of yield and quality consistent endive.Considering the consumption and quality of the endive and cost,the nutrient concentration level of E_0.8?0.8 ms / cm?was the most suitable for the production of endive hydroponics.