ارزیابی سطوح مختلف زئولیت بر تعدادی از شاخص های رشد گیاه توت روباه (Sanguisorba minor.L) تحت شرایط تنش شوری

Introduction: Climate change in recent decades has led to a decrease in the amount and pattern of rainfall distribution in arid and semi-arid regions of the world, including the Middle East.On the other hand, a significant amount of the world's water resources is affected by salinity. In general, the issue of water salinity in our country is a threatening factor in the success of biological projects and their effective implementation. In Iran, insufficient rainfall, severe water shortages and salinity of soils are the most important problems for the growth and production of crops and rangelands. Living and non-living environmental stresses, including salinity stress, are factors that limit crop production, which disrupt the natural metabolism of the plant and limit plant growth, and ultimately reduce yields, so solutions to combat salinity stress ‌ can have a significant impact on the process of increasing plant and livestock production, so by using some additives such as potassium zeolite under the brand name clinoptilolite in the soil can reduce moisture and salinity stresses created in the plant. Zeolites are porous materials that act like molecular sieves with their crystalline structure and, due to having open channels in their network, allow the passage of some ions and block the passage of some other ions. The selective adsorption and controlled release properties of zeolites help to improve plant growth if the correct type of zeolite used when added to the soil is selected by long-term increase in moisture and nutrients.
Materials and Methods: In the present study, the effect of zeolite on Sanguisorba minor under experimental salinity stress was performed in a completely randomized design with 3 replications in the greenhouse of Sari University of Agricultural Sciences and Natural Resources. This study was performed at four salinity levels (zero as control, -3, -6and -9bar sodium chloride). In this study, zeolite treatment included zero, 2 and 4% by weight per kg of soil. 20 Sanguisorba minor seeds were planted in plastic pots (with a mouth diameter of 25 and a height of 20 cm) at a depth of one centimeter and each pot was considered as an experimental plot. It was well disinfected to grow the pots and the bottom of the pot was drilled to create proper drainage. To accurately test all plastic pots filled with soil, they were weighed equally. Soil composition samples used in pots were transferred to a laboratory and analyzed to analyze soil characteristics. Pots containing zeolite treatments were regularly irrigated with normal water until the establishment of Sanguisorba minor seedlings (two-leaf stage) and after this stage until the end of harvest to apply stress. The number of sprouted plants was reduced to three plants after the removal of unfavorable factors. The experiment continued until the control treatment grew normally in the greenhouse. Finally, plant traits were measured. Analysis of variance was performed using SPSS software and the means were compared based on Duncan test at a probability level of one percent (P <0.01). Graphs were also drawn using Excell software.
Conclusion: In the study of zeolite factor on the studied traits, the results showed that the addition of zeolite along with the application of stress improved plant yield and had a significant effect (P≤0.01) on the modulation of stress due to salinity. In general, when zeolite was used in salinity treatment, the Sanguisorba minor plant showed a more favorable condition and the chances of survival of the Sanguisorba minor plant in salinity stress conditions increased -9 bar with 4% by weight of zeolite. While in salinity conditions, -9 bar and without zeolite, the plant was completely dried and destroyed. Because natural zeolites have the potential to reduce salt, the regulation of ionic and osmotic balance of the cell increases, and ultimately, yield increases as the amount of water consumed increases. Analysis of variance of Sanguisorba minor variables under salinity and zeolite stress showed that salinity and zeolite each had a significant effect on root length, stem length, underground dry weight and shoot dry weight. Also, the interaction effect of salinity and zeolite on all traits except the dry weight of underground organs has been significant at the level of one percent. In comparing the means, the effect of different levels of salinity and zeolite on the root length of Sanguisorba minor showed that there was no significant difference in root length at the level of non-salinity with 2% by weight of zeolite and zero salinity with 4% by weight of zeolite. However, at salinity levels of -3and -6bar, there was a significant difference between the consumption of zeolite. Also, no significant difference was observed in salinity level of -9 bar and zeolite of 2% by weight and 4% by weight. Also, in pots containing -3bar salinity without zeolite, they did not show a significant difference in terms of root length compared to the -6bar level and 2% by weight of zeolite. Comparison of the mean stem length of Sanguisorba minor at different levels of salinity and zeolite in greenhouse conditions indicated that there was no significant difference in the level of zero salinity with 2% by weight of zeolite and zero salinity with 4% by weight of zeolite. Also, at the level of -9bar salinity, this difference was not significant. This is while in other salinity levels with different amounts of zeolite, there is a significant difference in terms of stem length. Comparison of the average dry weight of groundwater at different levels of salinity and zeolite showed that at zero salinity level between 2 and 4% by weight of zeolite there is no significant difference. Also, there is no significant difference between salinity levels of -3 bar and no zeolite consumption and -6 bar without zeolite consumption. Also, at the level of -3bar salinity with 2% by weight of zeolite and -6bar salinity and 4% by weight of zeolite, no significant difference was observed in terms of dry weight of underground organs. The results of the effect of different levels of salinity and zeolite on the shoot dry weight of Sanguisorba minor also showed that each salinity level with values of 0, 2 and 4% by weight of zeolite is significantly different from other levels. However, at any level between 2 and 4% by weight of zeolite, there is no significant difference. The results of the correlation matrix between the studied variables Sanguisorba minor under salinity stress and zeolite showed that there is a very high correlation between root length and stem length of mulberry plant, as well as root length and stem length. They showed a high correlation with the dry weight of the underground organ and the dry weight of the aerial part at the level of one percent. The dry weight of the underground organ with the dry weight of the aerial part also showed a relatively high correlation at the level of one percent.