Effects Of A Compound Amino Acid Preparation On Stress Resistance Of Pak Choi And Cotton

In agricultural production,many abiotic stresses adversely affect crop growth,leading to inferior grain quality and a decline in crop yield.Exogenous amino acids can improve crop growth,crop qualities and yields,nutrient uptake of crop and fertilizer utilization efficiency.Moreover,application of amino acids can be an alternative to improve crop resistance to salinity stress,alkali stress,chilling stress,heat stress,drought stress,heavy metal,low light stress,etc.In this study,effects of a compound amino acid preparation（a patented product of Institute of Agricultural Resources And Regional Planning of CAAS,patent number ZL2014 1 0026086.5,hereinafter referred to as“preparation”）,which was made by the wastes liquids produced in the process of glutamate production,on crop growth and nutrient absorption and tolerance to abiotic stresses of pak choi（Brassica chinensis L.）were investigated by methods of seed germination experiment,seedling hydroponics experiment and potted fertilizer experiment.The results can provide theoretical guidance for uses of the preparation in agricultural production,especially under abiotic stress conditions.The main research results were as follows:（1）The preparation could suitably alleviate the inhibition of salt stress on the germination and seedling growth of pak choi.Compared with control,germination percentage of the treatment of seeds presoaked by 0.2 g/L preparation under 25,50,75 mmol/L NaCl concentration conditions was improved by 5.33%,7.27%and 29.20%,respectively.Application of 0.05 g/L preparation could improve SPAD value of pak choi seedlings,promote SOD,POD and CAT activities,maintain proline content,reduce producing rate and MDA content in leaves,and increase fresh biomass weight by 19.33%³6.18%than that without the preparation.（2）The preparation could suitably alleviate the inhibition of alkaline stress on the germination and seedling growth of pak choi.Compared with control,germination percentage of the treatment of seeds presoaked by 0.1 g/L preparation under 10,20 and 30 mmol/L Na₂CO₃ concentration conditions was improved by 6.56%,14.95%and 72.73%,respectively.Application of 0.05 g/L preparation under 2.5mmol/L Na₂CO₃ concentration condition could improve SPAD value of pak choi seedlings,promote root elongation and stem extension,improve or maintain SOD,POD and CAT activity,maintain pro content,and reduce producing rate and MDA content in leaves,and increase fresh biomass weight by 13.77%than that without preparation;0.1 g/L preparation had the best performance under 5 mmol/L and 10 mmol/L Na₂CO₃ concentration conditions,and fresh biomass weight increased by 40.68%and32.02%than that without preparation,respectively.（3）The preparation could alleviate the inhibition effect of temperature stress on the germination and seedling growth of pak choi in the test.Compared with control,germination percentage of the treatment of seeds presoaked by 0.1 g/L preparation under lower temperature（10°C）condition was improved by 9.27%;germination percentage of the treatment of seeds presoaked by 0.05 g/L preparation under hotter temperature（35°C）condition was improved by 8.86%.Application of 0.05g/L⁰.4 g/L preparation under 5°C and 10°C conditions could strengthen the activity of many antioxidant enzymes,thus reducing producing rate by 36.69%⁷2.61%and 26.68%⁷2.83%.Application of 0.1 g/L preparation had the best performance under 35°C,and producing rate was decreased by 72.61%.（4）The preparation added in the chemical fertilizer had multiple synergistic effect including improve pak choi growth,qualities and yields and increase nutrient absorption.Adding the preparation to common fertilizer could improve the yield pak choi by 17.58%,decrease nitrate content by 15.47%,and improve the contents of Vc,soluble sugar and soluble protein in the shoot by 12.42%,23.72%and3.01%respectively.The absorptive amount of N,P and K nutrients were increased by 17.61%,11.85%and 13.82%,respectively;fertilizer apparent utilization rate was improved by 43.01%.（5）It was investigated that the preparation played a certain role in alleviating the barriers to continuously cropped pak choi on a salt affected soil.In the latter two crops,adding the preparation to common fertilizer could improve the yield of pak choi by 11.85%and 14.41%,respectively,although the latter two crops showed a stubble barrier.（6）The preparation could improve cotton growth and yield and increase nutrient absorption on a salt affected soil.Compared to common fertilizer,adding the preparation can increase leaf branches,leaf area,SPAD value of different growth periods of cotton;improve dry matter accumulation and improve the weight of unginned cotton by 32.19%and lint yield by 41.49%;promote the absorption and utilization of nutrients during each growth period of cotton and the absorptive amount of N,P and K nutrients in the boll opening stage were increased by 24.46%,27.43%and 41.95%,respectively;improve the partial fertilizer productivity by 54.22%and agronomy efficiency by 32.48%,which illustrated that the preparation can reduce the fertilizer nutrient loss substantially.