Soad Y. S. El-Sayed , Rehab H. Hagab( 2020). Effect of Organic Acids and Plant Growth Promoting Rhizobacteria (PGPR) on
Biochemical Content and Productivity of Wheat under Saline Soil Conditions
Middle East Journal of Agriculture Research EISSN: 2706-7955 ISSN: 2077-4605
DOI: 10.36632/mejar/2020.9.2.20 Volume : 09 | Issue : 02| April-June | 2020
Pages: 227-242
Abstract: An experiment was done to examine the survival ability of the plant growth promoting rhizobacteria PGPR under investigation (Rhizobium leguminosarum and Paenibacillus polymyxa) under salt stress to ensure their efficiency in saline soil when they used as PGPR inoculants. Data revealed the initial screening by spotting on media supplemented with different concentrations of salt (0.3, 0.6, 0.9, 1.2 and 1.5M NaCl) in which indicated that R. leguminosarum and P. polymyxa were able to grow at all concentrations of NaCl with different log numbers. However, the growth was
reduced as the concentration of NaCl increased. Also, data revealed that both R. leguminosarum and P. polymyxa succeed to solubilize the phosphorus and produce IAA at the NaCl concentrations 0.3 and 1.5M NaCl. However, P. polymyxa show highest P-solubilization ability at different salt concentrations. The data also revealed the potentiality of testing PGPR in production of HCN and siderophores at different concentrations of NaCl, in which both PGPR have the ability to produce HCN and siderophores at 0.3 and 1.5M NaCl however P. polymyxa was superior in production of HCN and siderophore. A field experiment was conducted at the Sahl El-Hussinia, El-Sharkia governorate, Egypt during winter-growing season of 2018/2019 to study the effect of PGPR (R. leguminosarum and P. polymyxa) inoculants and foliar application of organic acids (humic and ascorbic acids) on wheat growth and productivity under salt stress. The experiment was laid out in randomized complete block design (RCBD).The results showed that, the best treatment was (AsA +HA+ mixture of PGPR) treatment has a high biological yield, which increased by 43.00%, grain yield by 43.11% and led to increases in 1000-grain weight by 35.19%. In addition, chemical constituents as (antioxidant activity, phenolic components and NPK uptake) of wheat crop gave the highest significant value by (AsA +HA+ mixture of PGPR) treatment. It is obvious from obtaining data in this study that all treatments play an important role in the alleviation of salt stress on wheat plants through their positive effect on biochemical contents of the plant.
Keywords: (PGPR, Chemical constituents, Humic acid, Ascorbic acid, Saline soil .)
