| چکیده انگلیسی مقاله |
Background and objectives: Parsley (Tagetes erecta) is an important bedding plant of asteraceae family. Environmental stresses, especially salinity stress in agricultural soils are increasing. Therefore, it seems necessary to find a suitable solution to reduce the effects of soil salinity and the possibility of cultivation in these types of soils. Meanwhile, growth-promoting bacteria are one of the important options as a factor to deal with these stresses. This research was carried out with the aim of the effect of growth stimulating bacteria as biofertilizers in making parsley plant resistant to salt stress.
Materials and methods: In order to investigate the effect of the application of growth-stimulating bacteria on reducing the effects of salinity stress in orange parsley, a research was conducted in the greenhouse of the Faculty of Agriculture of Zanjan University in 2022. This research was conducted as a factorial experiment in the form of a completely randomized design with treatments, three levels of salinity stress (0, 4 and 8 decisiemens) and three levels of Bacillus bacteria (control, Bacillus subtilis, Bacillus velezensis) in three replications, which in total It formed 27 experimental units. Morpho - physiologycal traits include: plant height, flower diameter, number of flowers, plant fresh weight, plant dry weight, root fresh weight, root dry weight, total chlorophyll, antioxidant, ion leakage percentage, peroxidase enzyme, proline, sodium, potassium and The ratio of sodium to potassium was calculated.
Results. The results of this research showed that the effect of salinity stress as well as the effect of bacteria on all traits was significant. The interaction effect of salinity in bacteria was significant in some traits such as fresh and dry weight of roots, diameter and number of flowers, leaf ion leakage percentage, total chlorophyll, peroxidase enzyme, proline, sodium and potassium percentage and sodium to potassium ratio. Based on the results of the comparison of averages, due to salinity stress, plant height, fresh and dry weight of shoot and root, diameter and number of flowers, chlorophyll, potassium percentage decreased significantly and in contrast to the characteristics of flower ion leakage percentage, peroxidase enzyme level, Proline, anthocyanin and antioxidants, sodium and the ratio of sodium to potassium increased. Also, the use of bacteria moderated the negative effects of salinity stress and by increasing the amount of proline, anthocyanin, antioxidant and increasing the amount of potassium, it led to the improvement of growth conditions in 8 and 4 deci siemens per meter salinity stress. Among the bacteria that were used, Bacillus subtilis showed a better response than Bacillus velezensis in ornamental parsley and reduced the effect of salt stress.
Conclusion: The results of this research showed that salinity induced negative effects on the morphological, physiological and biochemical characteristics of ornamental cabbage. Growth promoting bacteria reduced the negative effects of salinity stress through direct and indirect mechanisms. Among the bacteria that were used, Bacillus subtilis showed a better response than Bacillus velezensis in ornamental parsley and reduced the effect of salt stress. In other words, at high levels of salinity stress, the damage caused by salinity stress can be prevented by using growth-promoting bacteria. |