Effects of Flavobacterim, vermicompost and humic acid on antioxidant enzymes activity and some biochemical traits of triticale under soil salinity conditions

Soil salinity is one of the most important factors limiting the growth and yield of crop plants in arid and semi-arid regions, which causes lipid peroxidation and membrane damage by producing reactive oxygen species. Under such conditions, plants use enzymatic and non-enzymatic antioxidant mechanisms to prevent lipid peroxidation and increase malondialdehyde content. Application of plant growth-promoting rhizobacteria is another strategy that can improve plant performance under salinity stress and, consequently, plant growth increase by producing or releasing secondary metabolites such as regulators or growth hormones. Also vermicompost can directly increase plant yield by increasing plant nutrients and by acting on some antioxidant functions, controlling free radicals and thus protecting plants against environmental stresses. Humic acid also reduces the effects of salinity stress by improving protein synthesis, altering enzyme activity, solubility of micronutrients, improving soil structure, increasing cation exchange capacity and soil microbial population. Therefore, the aim of this experiment was to investigate the effect of salinity, vermicompost, flavobacterium and humic acid on antioxidant enzymes activity and some biochemical traits of triticale.

an experiment as factorial was conducted based on randomized complete block design with three replications in research greenhouse of faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabil during 2020. Factors experiment were included salinity at three levels (no application of salinity as control, application of 50 and 100 mM soil salinity by NaCl), and bio-fertilizers application (no application of bio-fertilizers as control, application of vermicompost, Flavobacterim, both application vermicompost and Flavobacterim) and humic acid foliar application (foliar application with water as control and foliar application of 2 g.L-1 humic acid).

The results showed that the combined application of vermicompost, flavobactrim and foliar application humic acid under 100 mM soil salinity conditions, increased proline content (50%), soluble sugar (45.37%), anthocyanin content (57.14%) and the activity of catalase, peroxidase, polyphenol oxidase (54.88, 48.47 and 48%, respectively) compared to no application of biofertilizers and humic acid under non-salinity conditions. Also, the combined application of vermicompost, flavobacterium and foliar application of humic acid under non-salinity conditions decreased 54.26% of malondialdehyde content and increased 69.56% of grain yield compared to the no application of biofertilizers and humic acid under 100 mM soil salinity conditions.

It seems that the application of biofertilizers and foliar application of humic acid can increase grain yield under salinity stress by improving the antioxidant enzymes activity and the compatible osmolytes content.