The effects of Bacillus safensis, B. pumilus and Zhihengliuella halotolerans isolated from rhizosphere of halophyte plants on some physiological characteristics of Triticum aestivum (var. Ghods) under salinity

Reducing wheat production due to salinity stress is one of the most important food security challenges worldwide. Plant rhizosphere bacteria reduce the effect of salinity stress on plants, including wheat, by mechanisms such as modulating plant hormones, making nutrients available to the plant, and combating pathogens. This study was designed and performed with the aim of increasing the salinity resistance of wheat (var. Ghods) using salinity-resistant growth-promoting bacteria isolated from the rhizosphere of several halophyte plants in Yazd province.

Growth-promoting traits and salinity resistance of bacteria isolated from rhizosphere of plants Atriplex lentiformis (Torr.) S. Watson، Tamarix ramosissima Ledeb. Seidlitzia rosmarinus Ehrenb. ex Bois and Halostachys belangeriana (Moq.) Botsch. were investigated. Wheat seeds were inoculated with superior bacteria in terms of growth-promoting traits and salinity resistance, including Bacillus safensis, Bacillus pumilus and Zhihengliuella halotolerans. During the growth period, physiological parameters of chlorophyll a, chlorophyll b and total chlorophyll, proline, enzymatic activity of antioxidants, phenol and total soluble sugars in the leaves were measured.

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. The results of wheat leaf analysis showed that with increasing salinity, (without bacteria inouculation) chlorophyll content in all treatments decreased, instead the amount of proline, antioxidant activity, the amount of phenol and the amount of soluble sugars decreased compared to the control (0.2 ds/m). The use of bacteria increases chlorophyll a, chlorophyll b, total chlorophyll, proline, total phenol, total antioxidants and total soluble sugar compared to without bacteria inoculation treatment.

The growth-promoting bacteria under study with a set of growth-promoting mechanisms significantly improved the resistance of wheat to salinity stress. Therefore, the bacteria studied in this experiment can be used to reduce the effects of salinity on wheat var Qhods under saline irrigation. B. safensis, in salinity of 8 ds/m, more than the other two bacteria, improved the physiological indices of salinity resistance of Qods wheat. Since this experiment was performed under greenhouse conditions, it is recommended that this experiment be performed in field conditions to complete the findings.