Effects Of PH And Salt Stress On Yield And Quality And Related Physiological Metabolism Of Ginger

Soil salinization is a universal ecological problem in the world,which seriously affects the growth of plants and the yield of crops.To investigate the response of ginger to pH and saltsalt stress,this experiment took'shannong 1'ginger as a test material,and used a combination of nutrient solution sand culture and soil pot cultivation to study the interaction between nutrient solution and soil pH and saltsalt.Effects of stress on yield and quality and related physiological metabolismg of ginger and.The main findings are as follows:1.The relationship between pH and salt level of sand cultured ginger nutrient solution and yield and quality was determined by using secondary saturated D-optimal design,and the relevant mathematical model was established.The model analysis shows that the effect of salt on yield and quality of ginger is greater than that of pH,and there is a significant interaction between the two.The change of pH at a lower level had no significant effect on the yield and quality of ginger.When the pH value exceeded 7.70,the yield decreased rapidly with the increase of pH.With the increase of salt level,the yield of ginger continued to decrease,but within the range of Na⁺content of 77.91 mmol·L^-1,the quality of ginger showed a trend of improvement with the increase of salt level.2.pH and saltsalt significantly affected the growth of ginger,and the fresh weight of root,stem,leaf and rhizome significantly decreased under different pH and salt stress.For example,the root fresh weight treated with 0.35%and 0.7%salt level in seedling stage decreased by10.8%and 27.3%,respectively,compared with the control group without salt stress.With the development of growth,the difference between the growth amount of each organ under pH and saltsalt and the control gradually increased.For example,pH 8.0 of root fresh weight in seedling stage,growing stage and rhizome swelling stage decreased by 39.2%,46.1%and51.2%,respectively,compared with pH 7.0.The fresh weight of root treated with 0.35%and0.7%salt level decreased by 20.2%and 44.0%,respectively,pH 8.0 reduced yield by 61.3%from pH 7.0.3.With the extension of pH and saltsalt stress time,the contents of osmotic regulators such as proline,soluble sugar and organic acid in ginger root increased first and then decreased,and the differences among treatments increased.Under pH and saltsalt,ginger organs significantly increased content of Na⁺,K⁺content is significantly reduced,K⁺/Na⁺fell sharply,in accordance with the growth of processing such as seedling stage of salt levels were0.35%,0.7%stress of ginger leaves K⁺content were 16.48 mg/g,12.14 mg/g,K⁺/Na⁺were2.99 and 1.59,respectively to the rhizome expands period K⁺content dropped to 13.53 mg/g and 8.34 mg/g,K⁺/Na⁺were 1.40,0.59;The increase of pH also significantly reduced K⁺content and K⁺/Na⁺.The contents of Ca²⁺,Mg²⁺and Zn²⁺showed a similar trend with that of K⁺.4.pH and saltsalt stress caused the increase of H₂O₂ content and superoxide anion generation rate in ginger leaves,and with the development of growth,the level of reactive oxygen increased,the difference between treatments increased.The activity of SOD,POD,CAT and other protective enzymes also showed a similar trend of increasing first and then decreasing with the extension of treatment time.The AsA/DHA and GSH/GSSH ratios of ginger leaves during the whole growth period increased and then decreased under salt stress.APX,GR,DHAR and MDHAR showed a similar trend in related enzyme activity.The effect of pH on relevant metabolism was basically the same as that of salt stress,and the effect of salt and pH on reactive oxygen metabolism in ginger leaves had significant interaction effect.5.Photosynthetic pigment content,stomatal conductance?Gs?and net photosynthetic rate?Pn?in ginger leaves continued to decrease with the extension of stress time.The change trend of intercellular carbon dioxide concentration?Ci?is opposite to that of stomatal limit?Ls?.The content of chlorophyll a in leaves treated with 0.35%and 0.7%salt levels in seedling stage decreased by 14.9%and 21.6%,respectively,compared with that in control stage.Compared with pH 7.0,pH 8.0 decreased 22.1%,36.4%and 44.6%in three periods,respectively.6.The activities of urease,invertase and alkaline phosphatase in soil decreased to different degrees under pH and saltsalt.Under pH and saltsalt,the phylum dominant flora in rhizosphere of ginger was Proteobacteria,Chloroflexi and Acidobacteria.The horizontal dominantfloraofthegenuswasnoranknorank_f<sub>A4b,norank_f<sub>norank_o<sub>norank_c<sub>subgroup₆,norank_f<sub>norank_o<sub>SBR1031.When the pH was 8.0 and the salt level was 0.35%,the total number of species of ginger rhizosphere bacteria was significantly reduced.In this experiment,the effects of salt?pH:7.0,salt level:0.35%?,pH?pH:8.0,salt level:0%?,and pH and salt interaction stress?pH:8.0,salt level:0.35%?on the bacterial community structure were similar.