Physiological And Biochemical Responses Of Brassica Oleracea To Different Salt Concentration Treatments

Fujian is located in the coastal zone with high salt concentration in the soil to ensure the high quality and high yield of the purple cabbage production.In this study,the Brassica oleracea L variety "Purple Gan 85"was used as the test material,and 5 different concentrations of NaCl treatment were set up with hrdroponic method.The concentration was 0(T1),40(T2),80(T3),120(T4)and 160(T5)nmol/L respectively.The growth and physiological characteristics,pigment content and Photosynthesis of different concentration salt treatment on the seedlings of purple cabbage were studied.The effects of chlorophyll fluorescence parameters,leaf senescence and antioxidant enzyme system were studied.The main results are as follows:1、The results showed that different concentrations of salt treatments have different effects on total root length,total surface area,volume,root number,root tip number,root diameter,root activity,plant height,stem diameter and dry weight.The improvement of root length,total surface product,volume,root number,root tip number,root mean diameter and root vitality of root are most favorable for T2(40.00nmol/L)treatment.At a certain salt concentration,the root growth of seedlings was inhibited in varying degrees with the increase of salt concentration,and the growth of seedling height was inhibited by salt treatment at different concentrations.T2 treatment was beneficial to increase the stem diameter,dry weight and root shoot ratio of seedlings,and the maximum seedling index under T2 treatment was the largest.It indicates that T2 treatment is most conducive to the growth and development of purple cabbage seedlings.2、The effects of different concentrations of salt treatment on pigment content,photosynthesis and chlorophyll fluorescence parameters of purple cabbage seedlings were studied.The results showed that the contents of chlorophyll a,chlorophyll b and chlorophyll(a+b)in the seedlings treated with T2 were all the highest.The content of carotenoids decreased with the increase of salt concentration,and the net photosynthetic rate,transpiration rate,intercellular carbon dioxide concentration,stomatal conductance and water use rate decreased with the increase of salt concentration,and T2 treatment helped to improve the Fv/Fm of seedlings.PS,ETR and NPQ increase with the increase of salt concentration,while qP decreases with the increase of salt concentration.3、The effects of different salt treatment on the soluble protein,soluble sugar,malondialdehyde,proline content and SOD,POD and CAT activity in the shoot and root of purple cabbage were studied.The results showed that salt treatment could help to improve the soluble sugar content of seedlings,and the higher the concentration of salt,the more obvious the treatment effect.The content of soluble protein in the seedlings decreased with the increase of salt concentration,the higher the salt concentration,the more obvious the inhibition effect on soluble protein;the content of malondialdehyde and proline increased with the increase of salt concentration;SOD,POD and CAT.When the activity was treated with 5-15d,with the increase of salt concentration,the activity of SOD,POD and CAT in the seedlings treated with T1 and T2 increased,while the SOD,POD and activity of T3,T4 and T,decreased significantly,and the higher the concentration,the more obvious.4、The effects of different concentration salt treatment on the fresh weight,soluble sugar,soluble protein,vitamin C,anthocyanin and nitrate content of purple cabbage after colonization were studied.The results showed that T2 and T3 treatment improved the fresh weight of purple cabbage,and T3 treatment had the most obvious effect on the fresh weight of purple cabbage,T4 and T5 treatment reduced the fresh weight of purple cabbage.T2,T3,T4 and T5 treatment improved the soluble sugar content of purple cabbage,and the most significant effect was treated with T3;the soluble protein content T2,T3 and treatment were all helpful to the increase of soluble protein content.Obviously,T5 treatment could reduce the content of soluble protein;T2,T3,T4 and T5 could help to increase the content of anthocyanin,and the most obvious effect under T3 treatment;vitamin C content was the most significant with T3 treatment;the content of nitrate in purple cabbage under T2 treatment was the lowest,while T3,T4 and T5 treated nitrate content increased with the increase of salt concentration.The results of the comprehensive evaluation of the yield and quality of purple cabbage after the salt concentration treatment showed that the 80nmol/L was the most beneficial to the yield and quality of the seedlings.