The effect of Bacillus safensis, Bacillus pumilus and Zhihengliuella halotolerance isolated from rhizosphere of halophyte plants on yield, yield components and seed starch of wheat (var. Ghods) under salinity stress

The demand for wheat as the most important grain used by humans is increasing. Due to climate change and improper soil and water management, salinity stress reduces wheat yield. The use of plant growth promoting rhizobacteria is a nature-friendly way to reduce the effects of salinity stress on wheat yield. The aim of this study was to evaluate the effect of plant growth promoting bacteria isolated from the rhizosphere of several saline plants in Yazd province on total biomass and yield components of wheat (var. Ghods).

Plant growth promoting characteristics and salinity resistance of bacteria isolated from rhizosphere of Atriplex lentiformis, Seidlitzea rosmarinus, Tamarix ramosissima and Halostachys belangeriana were investigated. Wheat seeds were inoculated with superior bacteria including Bacillus safensis, B. pumilus and Zhihengliuella halotolerans and after planting in the pots in greenhouse conditions was irrigated with water with salinities of 4, 8, and 16 ds/m.

All three bacteria were able to produce auxin. The highest amount of auxin production was measured in B. safensis (29.72 μg / ml). All three bacteria were able to produce hydrogen cyanide and the highest amount of hydrogen cyanide production was observed in Z. halotolerans with grade 5 (very high). All three bacteria were able to produce siderophore. ACC deaminase production was observed in all three bacteria and the highest amount was measured in B. pumilus at 8 μg / ml. Ability to dissolve phosphate in Z. halotolerans was more than twice that of B. safensis. Salinity reduced all the measured indices in wheat. In bacterial inoculated treatments at all salinity stress levels (4, 8 and 16 ds/m), the average of total biomass, amylose and amylopectin increased up to 52.5, 21.3 and 10.3%, respectively, compared to the average of these indices in control treatments (without bacteria) in the same salinity levels. Also, bacteria in these levels increased spike weight, seed weight and number of seeds up to a maximum of 22, 74.6 and 66.6%, respectively, compared to the control (without bacteria) of these salinity levels.

the plant growth promoting bacteria increased yield components of wheat under salinity stress, therefore to reduce the effects of salinity on wheat under saline irrigation conditions; the bacteria studied in this experiment can be used. Z. halotolerans was more efficient than other two bacteria in all of the studied indices. Since the experiment was performed under greenhouse conditions, it is recommended that this experiment be performed in the field.