جستجوی مقالات مرتبط با کلیدواژه "salinity stress" در نشریات گروه "زراعت"

Vermicompost increases the ability to absorb water and has a great effect on improving the physical, chemical, and biological properties of the soil. The present study investigates the effects of salinity stress and vermicompost on Euphorbia tirucalli L.in pot culture conditions.

Plants were cultivated under three salinity treatments of 4, 8 and 12 dsm-1 alone and with the use of vermicompost at the levels of 10, 20 and 30 % of the soil were tested factorially in the form of a completely randomized design. Growth parameters including length, dry and fresh weight (whole plant, root and shoot) and content of photosynthetic and non-photosynthetic pigments, soluble sugars and proline were measured in the plant.

According to the obtained results, the increase in salinity levels had a negative effect on the growth parameters, while the combined use of vermicompost fertilizer increased the length and dry weight of aerial parts at all salinity levels. Regarding the root dry weight, an upward trend was observed at the highest salinity level (12 dsm-1) at all vermicompost the use of levels. According to the results of this research, the use of salinity stress reduced chlorophyll pigments, but the use of vermicompost fertilizer at the highest level (30 percent vermicompost) reduced the negative effects of salinity on them and increased their amount despite the high concentration of salt. In the case of carotenoid pigments, severe salinity (12 dsm-1) decreased their amount, but the use of vermicompost at this level of stress increased it. Also, the results of this research showed that the amount of anthocyanin pigments in medium and severe salinity (8 and 12 dsm-1), increasing the level of vermicompost decreased the amount of this compound in the aerial parts of the plant. The amount of proline and soluble sugars of shoots and roots also went up under the influence of different salinity levels. In the case of soluble sugars, the use of vermicompost at low levels of salinity caused an increase, and at higher levels of salinity, the use of 30% vermicompost treatment decreased these compounds. In the case of proline, the use of fertilizer in high amounts led to the reduction of this compound at higher levels of salt.

In general, the results of this research showed that the use of vermicompost, especially at higher levels, could reduce the negative effects of high salt concentrations on Euphorbia tirucalli L.and improve the plant's morphophysiological responses to salinity stress.

In modern agriculture, identifying salt-tolerant plants is crucial for efficient utilization of saline water and enhancing productivity. However, plant salt tolerance can vary across different growth stages. Basil (Ocimum basilicum L.), an annual herb belonging to the Lamiaceae family, not only imparts an exquisite flavor to our meals but also possesses remarkable medicinal properties and diverse applications. Given the significance of basil and the widespread challenge of soil salinity, a research study was conducted to investigate the effect of salinity stress on germination and seedling characteristics of basil. This experiment was designed as a completely randomized block design with 4 replications in the Agronomy Laboratory. 4 salinity levels (0, 50, 100, and 150 mM) were imposed using sodium chloride salt. All data were analyzed using the SAS software. Mean comparisons were performed using Duncan's test at a 5% probability level. The results demonstrated that soil salinity significantly impacted basil germination and seedling growth. The highest percentage and rate of germination, stem and root length, and fresh and dry weight of seedlings were observed in the control treatment (without salinity). Conversely, the lowest values of these parameters were recorded in the 150 mM salinity treatment. These findings indicate that basil is sensitive to salinity stress, and increasing soil salinity substantially impairs its germination and growth.

Salinity of water and soil resources is one of the most basic agricultural problems, especially in arid and semi-arid regions. Identifying and domesticating salinity-resistant plant (halophytes) species with economic value is an important strategy for these regions.

This research aimed to investigate the amount of elements and the quality of fodder in several Salicornia species under the influence of water salinity in a factorial experiment with a completely randomized design in pot culture conditions in Bojnourd (North Khorasan province) in 2018. Irrigation treatment was applied at two levels (brackish water and normal water), and Salicornia species treatment included four species (Salicornia persica, S. sinus persica, S. europaea, and S. bigelovii) and Salicornia var Markazi. The source of salty water was the Kal-Shoor river in Esfrain and the source of normal water was the well located in Research and Education of Agriculture and Natural Resurces Center in Bojnourd. Due to the high salinity of Kal-Shoor river, normal water was used to adjust the salinity to the treatment limit of 45 dSm-1. To produce seedlings, Salicornia seeds were planted in plastic combs for seedling production in April 2018. After 60 days, seedlings (10-15 cm) were transferred to pots. The irrigation circuit varied in different growth stages according to weather conditions, and irrigation was done by the weight method with the 80% moisture index of the pots.

The results showed that the amount of nitrogen, phosphorus, potassium, magnesium, sodium and chlorine increased with the increase in irrigation water salinity in all species. The highest accumulations of sodium (11%) and chlorine (23.5%) were observed in S. sinus persica and the lowest amount of sodium (8.6%) and chlorine (21%) were observed in S. persica. Among the Salicornia species, the lowest amount of elements is related to potassium and phosphorus ions, which is mostly due to the limitation of the absorption of these elements under the influence of sodium ions, and as mentioned in the sources, the process of absorption of these elements increases gradually with the growth stages. Maintaining a more negative potential of the membrane is an important factor for salinity tolerance, considering that in saline soils, chlorine and sodium are the most common solutes, the absorption of sodium and chlorine ions is important for regulating osmotic pressure and cytoplasmic concentration. In this experiment, in both irrigation treatments, the most elements in all species were related to chlorine and sodium ions. Based on the measurement of quality variables of fodder, the percentages of protein, crude fat, and ash in salty water treatment were higher than those in normal water. The highest percentage of crude fat (1.32%) in S. var. Markazi was affected by saltwater treatment, which was significantly different from the other species. The highest percentages of protein in S. bigelovii and S. europaea under the influence of saltwater treatment were 6.06% and 6.31%, respectively, which were significantly different from the other species. The highest amounts of ash belonged to S. europaea (63%) and S. bigelovii (62%) in saltwater treatment, and S. sinus persica contained the least ash (49%) in normal water treatment. Although the increase in protein increases the quality of fodder, the increase in the amount of ash and crude fat causes limitations in animal nutrition and digestibility. Therefore, the increase of water salinity has a negative effect on the quality of fodder.

Brackish water treatment increased the amount of ash in all species to different proportions, which is a limiting factor for the pure consumption of salicornia in animal feed. Therefore, the relative reduction of water salinity and the selection of suitable species are effective in increasing the quality of fodder.On the other hand, the great ability of Salicornia species to absorb and store salts in their aerial parts provides the basis for the exploitation of their vegetative organs for the production of vegetable salt. Moreover, it is economically important along with other applications of Salicornia (production of fodder, oil, medicines, and protection).

Salinity is one of the major abiotic stresses and the most limiting factor in agricultural production worldwide, affecting the growth, development, and final yields of crops. Rapeseed is one of the most important sources of oilseeds in the world, and its seeds contain more than 40% of oil. Moreover, the meal obtained from oil extraction has more than 35% protein, hence it currently ranks third among oil crops in the world after soybean and oil palm, making it necessary to identify the genotypes that tolerate salinity stress. The development and improvement of rapeseed cultivars with salinity tolerance and acclimation offer promising prospects for improving sustainable production in this area. Therefore, the current study aimed to investigate the responses of rapeseed genotypes to salinity stress through analyses of agronomic and biochemical traits.

The genetic diversity between rapeseed lines in terms of agronomic, morphological, and physiological traits in saline soils was investigated in an experiment based on a randomized complete block design with 17 autumn rapeseed genotypes with three replicates in the research farm of East-Azarbaijan Agricultural and Natural Resources Research and Education Center. The measured traits were plant height, the number of fertile pods, number of seeds per pod, pod length, pod area, plant growth rate, 1000-seed weight (TSW), seed yield, oil content, and oil yield. The relationships between yield, yield components, and morphological traits were explored using the analysis of variance (ANOVA), comparison of averages, correlation analysis, cluster analysis, and biplot to understand the relative importance of traits affecting the yield of the studied genotypes.

The studied genotypes were significantly different from each other in pod length, pod area, number of fertile pods, number of seeds per pod, plant growth rate, seed oil percentage, plant height, TSW, grain yield, and oil yield. However, there were no significant differences between the studied genotypes in terms of harvest index and number of actual pods to potential pods. According to the mean comparisons, genotypes 5, 11, and 15 can be introduced as salinity-tolerant lines, and genotypes 2, 4, 6, 9, and 12 can be considered salinity-sensitive lines. According to the other traits, genotype 11 produced a high pod length, number of fertile pods, oil percentage, and oil yield, genotype 5 had a high growth rate and oil percentage, and genotype 15 presented a high height and number of fertile pods. According to the cluster analysis, the second and third groups contained tolerant and susceptible genotypes, respectively. The genotypes in the second group had the highest percentage of positive deviation from the overall mean for grain yield, plant height, harvest index, seed oil percentage, pod length, pod area, and number of fertile pods. Based on the biplot analysis, Karaj 8 and 14 genotypes had a strong relationship with the number of  fertile pods, number of seeds per pod, pod length, pod area, and plant growth rate. Based on the obtained results, the plant height, TSW, seed yield, and oil content traits were closely correlated with Karaj 5, 7, 11, 10, and 15 genotypes. Based on the results of correlation analysis, the correlation coefficient of seed yield was positive and significant for three traits, i.e., plant height, oil percentage, and number of fertile pods, and the highest correlation coefficient (r = 0.879) was obtained for seed yield with seed oil percentage. Positive and significant correlations were measured for the number of seeds in pods with pod length (r = 0.699), pod area (r = 0.555), number of fertile pods (r = 0.678), and number of actual pods. Therefore, genotypes characterized by longer and more abundant pods play a crucial role in improving seed quantity, a key component of grain yield in saline environments. Consequently, the size and number of pods per plant serve as indicators of high-yield potential under such conditions. Based on the results of the principal component analysis (PCA), the first and second components had the highest relative variances, accounting for 44.66% and 31.22% of the total variance, respectively. Together, these two components accounted for 75.88% of the total variance. Factor loadings showed that traits such as number of fertile pods, seed yield, oil yield, and seed oil content had the highest factor loadings in the first component. Similarly, the plant growth rate had the highest factor load in the second component among all the studied traits. Cluster analysis divided the genotypes into four groups, and its dendrogram showed that all the studied genotypes were divided into four separate groups based on all the measured traits. The first group comprised three Karaj 1, 13, and 16 genotypes, the fourth group (like the first group) contained three Karaj 5, 11, and 15 genotypes, and the third group had five genotypes, namely Karaj 3, 7, 8, 10, and 14. The remaining genotypes were assigned to the second group.

The results of the present study demonstrate acceptable genetic diversity among rapeseed genotypes in terms of the evaluated traits in saline lands. This shows the importance and the possibility of using these genetic resources to achieve promising and superior genotypes in breeding programs.

Among abiotic stresses, Salinity has been increasing over the time for many reasons like using of chemical fertilizers, global warming and rising sea levels. In deed salinity stress and high concentration of ions are of the most determinative factors that simultaneously affect genetical, biochemical and physiological processes of a plant. Some of plants known as halophytes have developed mechanisms that help them to avoid or tolerate the saline conditions. With the aim of understanding the probable mechanisms of saline tolerance in Aeluropus littoralis (as a halophyte) and the saline susceptibility of Oriza sativa var. IR64 (as a glycophyte), In the present study, the similarity of Cu/Zn Superoxide Dismutase (Cu/Zn SOD) gene sequences, the differential biochemical indexes such as aromatic and instability indices of them were evaluated in silico, based on amino acid composition of their Cu/Zn SOD. the gene expression pattern and fluctuation of Cu/Zn SOD as a ROS scavenger (in root and shoot) was also assessed and compared in a span of exposer time to stress and different salt concentratio

The seeds of A. littoralis and O. sativa var IR64 were prepared from Center for Research of Agricultural Science and Natural Resources (CRASN) which were sown in sand as a primary culture medium, after surface sterilization. After 21 days, the seedlings that had grown uniformly were transferred to continuously aerated hydroponic pots containing Yoshida nutrient solution. we established a stress span containing short term (6 hours), mid-term (24 and 48 hours) and long term (6 and 11 days) exposure to salinity stress. the gene expression pattern and fluctuation of Cu/Zn SOD as a ROS scavenger in Aeluropus, was evaluated at the sampling points of 6 h/100 mM, 6 h/200 mM, 6 h/300 mM, 48 h/300 mM, 144 h/300 mM and 264 h/300 mM. the elite sampling timepoint of rice, were also 6 h/30 mM, 6 h/60 mM, 6 h/100 mM, 48 hours/100mM, 144 hours/100 mM and 264 hours/100 mM. To study the structure of genes, genomic DNAs of A. littoralis and Oryza sativa L. Var IR64 were isolated from their leaf. Amplification of Cu/Zn SOD genes was performed with specific primers designed based on NCBI sequences. Amplification of their the maximum length fragments was carried out using a hot start, high fidelity DNA polymerase. The extracted fragments were cloned using pTZ57R vector in Escherichia coli (DH5α strain) and sequenced paired-end. The results were analyzed using NCBI database, and the biochemical features related to their proteins, such as isoelectric points, calculated weight, instability and aromatic indices, were analyzed Insilco using CLC Genomics Workbench 12 and Geneious Prime 2019.

Comparison of the real time quantitative PCR of Cu/Zn SOD transcriptome in roots showed that Aeluropus increase the expression of these genes faster and keeps their expression in long-term while rice loses them significantly. The increased expression of Cu/Zn SOD in the roots of Aeluropus maintained but its expression in rice down regulated. rice did not show any statistically significant changes in compare to control samples and persisted in this manner until the end of investigation. But in Aeluropus, the expression showed another increase after 264 hours of being in 300mM. In the shoots of Aeluropus, the level of Cu/Zn SOD expression increased gradually and reached its highest level after 48 hours commencement of 300 mM salinity stress. While shoots of IR64 Rice did not show any statistically different expression except a very late response at 144th hour of being in 100 mM salinity stress that was only about 40 percent higher than its counterpart control samples. Analysis of amino acid sequences' indices showed that Cu/Zn SOD of Aeluropus would have a superior stability and higher aromatic value in contrast to IR64 counterpart. These indices originate from the arrangement of amino acids which they themselves are the result of nucleotide arrangement in genome.

The early and highly expression of Aeluropus Cu/Zn SOD gene studied in our experiment and their permanency and lasting of their activity in high concentration of salinity makes the sequence of it and its regulatory elements as a prospective candidate for future applied studies and transforming and improving salinity tolerance in many Poacea crops.

This study was conducted with the aim of investigating the effect of salinity stress and different temperatures on germination and determining the cardinal temperatures of germination (basic, optimal and ceiling germination temperatures) of two sugar beet cultivars. Experimental treatments included different levels of salinity stress (0, 40, 80, 120 and 160 mM) and different temperatures (5, 10, 15, 20, 25, 30, 35 and 40 °C). The three-parameter sigmoidal model was used to determine the time to reach 50% germination. The results showed that temperature and salinity stress had an effect on germination percentage and germination rate. In addition, the results showed that with increasing temperature up to optimum temperature, the germination percentage and germination rate increased, and with increasing salinity stress, the germination percentage and also the germination rate decreased. The germination percentage and germination rate in Brigitta variety was higher than that of Shokofa variety. According to the RMSE, CV, R2Adj, SE parameters, the beta model was the most suitable model for both sugar beet cultivars. In the Brigitta variety, the base temperature is between 3.67 and 5 °C, the optimal temperature is between 16.67 and 26.35 °C, and the roof temperature is between 40.10 and 40.89 °C, and in the shokofa variety, the base temperature is between 2.88 and 2.80 °C. 5.65, the optimum temperature varied between 16.11 and 26.47 °C and the ceiling temperature between 39.94 and 42.94 °C. The obtained results showed that the percentage and speed of germination in Brigitta variety under salinity stress conditions and different temperatures was higher than that of Shokofa variety, but there was no significant difference between the two varieties in terms of cardinal temperatures. Therefore, by using the output of these models at different temperatures, it is possible to predict the germination speed at different potentials.

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. 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. 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.

In order to investigate the effect of salinity on soybean germination, the project was performed as factorial experiment based on completely randomized design with three replications in laboratory of Mazandaran Agricultural and Natural Resources Research and Education Center in 2020. The treatments were 11 soybean cultivars (Williams, Saba, Tapor, Sari, Amir, Caspian, Kosar, Katul, Sahar, Telar and Nekador) and four salinity levels (0, 20, 40, 60 mM of NaCl). Analysis of variance showed that the effect of salinity, genotypes and interaction of theme in all traits were significant at 1% probability level. With increasing salinity, all traits value in all genotypes decreased. Mean comparison of variety treatment showed that the highest germination percentage was observed in Katul cultivar (83.33%). The Mean comparison of interaction effect showed that the highest values of the traits were observed in the combination of cultivars and 0 mM concentration, and with increasing salinity level, the amount of traits decreased and their lowest value was in the combination of cultivars and 60 mM. Cluster analysis put the studied genotypes into three groups. Correlation analysis showed that all correlation coefficients were positive and significant, and the germination rate had the highest correlation with the germination percentage (0.88) and total dry weight (0.78). The germination percentage was the first trait that entered to the regression model of germination rate and was able to justify 0.77 of variances. Among different cultivars, Amir and Saba cultivars were recognized as tolerant cultivars and Sahar and Williams cultivars as sensitive cultivars.

Salinity stress is a significant factor that imposes limitations on the growth and productivity of crops. Like other living organisms, plants are susceptible to various stresses and can suffer damage when exposed to them.Under conditions of salinity stress, the stages of germination and seedling growth become particularly crucial in the life cycle of plants.Artemisia annua L., an important medicinal plant with a long history of use in traditional Iranian and other Asian medicine, was the subject of investigation in this research.The aim was to examine the impact of salinity stress on the germination process(both in terms of percentage and rate)and the characteristics of seedlings(such as radicle length,plumule length, fresh weight, and dry weight)in Artemisia annua L.The study was carried out in 2023,employing a completely randomized design with four replications at the Department of Agronomy in Shahid University.The experimental treatments consisted of four levels of salinity(0,50,100,and150 mM)induced by sodium chloride salt.The data obtained were analyzed using SAS software, and the means were compared utilizing the Duncan test at a 5%probability level.The findings of this experiment demonstrated that the control treatment(without salinity)exhibited the highest percentage and speed of germination, as well as the longest radicle and plumule lengths, and the greatest fresh and dry weights of the seedlings.Germination was not observed at concentrations of 150mM and higher.Hence, based on the outcomes of this study, it can be concluded that salinity stress has an adverse impact on the germination process and seedling growth of Artemisia annua L.,revealing the plant's heightened sensitivity to salinity.

Ajowan is one of the important medicinal plants of the Apiaceae family, whose essential oil is used in the pharmaceutical and cosmetic industries. Soil salinity is considered one of the most important factors limiting the growth of agricultural plants due to the prevention of the absorption of water and nutrients into the plant. Using biofertilizers with plant-growth-promoting bacteria is one of the most effective ways to reduce the toxic effects caused by high salinity in plant growth. Therefore, this study was conducted with the aim of investigating the effect of different planting dates and biofertilizers on seed yield and agronomic indicators of Ajowan medicinal plant under salt stress.

In order to investigate the effect of biofertilizers on seed yield and vegetative parameters of Ajowan medicinal plant in the climatic conditions of Kashmar, two separate experiments were conducted in the field and greenhouse conditions of Kashmar Research Center. A field experiment in the form of a split plot design using two factors, the first factor included planting date in two levels (March 26, April 27), the second factor included biological fertilizer in 8 levels (1) Control 2) Azetobarvar1 3) Phosphate barvar2 4) Petabarvar2 5) Azetobarvar1 + Phosphatebarvar2 6) Azetobarvar1 + Petabarvar2 7) Phosphatebarvar2 + Petabarvar2 8) Azetobarvar1 + Phosphatebarvar2 + Petabarvar2). The second experiment was conducted as a factorial in a completely randomized design in the greenhouse. The investigated factors included biofertilizer at 8 levels (1) Control 2) Azetobarvar1 3) Phosphate barvar2 4) Petabarvar2 5) Azetobarvar1 + Phosphatebarvar2 6) Azetobarvar1 + Petabarvar2 7) Phosphatebarvar2 + Petabarvar2 8) Azetobarvar1 + Phosphatebarvar2 + Petabarvar2), and salinity stress at 3 levels (zero, 4 and 8 dS/m).

The results indicated that salinity stress significantly reduced the traits of germination percentage, root length, seedling length. The use of biological fertilizers in combination had the best effect on these traits compared to the control. Also, in the treatment of no application of biofertilizer and in the condition of salinity stress of 8 dS/m, the above traits had the lowest values. Also, the combined treatment of Azetobarvar1 + Phosphatebarvar2 + Petabarvar2 could significantly improve the crop yield and plant height. The studies showed that the best planting date for plant height, number of sub-branches, number of flowers, Thousand grain weight and Grain yields was obtained on the planting date of March 26 compared to April 27.

In general, it can be stated that the use of combined biological fertilizers in can reduce the destructive effect of salinity stress on the Ajowan medicinal plant and also significantly increase the seed yield in field conditions.

The use of seed priming methods has been introduced today as one of the factors to increase the germination and establishment of seedlings and plant under adverse environmental conditions, especially salinity. Therefore, in this study, the effect of seed priming with gibberellic on germination and consumption of triticale seed storage materials under salt stress conditions was investigated. The experimental treatments in this study were 5 levels of salinity stress (zero, 40, 80, 120 and 160 mM) and 4 levels of seed priming (zero, 25 and 50 ppm gibberellic acid and control seed without prime) with 3 replications. The results showed that the highest percentage of germination (95.33%), germination index (41.65 seeds per day), seedling length (19.27 cm) and the percentage of normal seedling (95.33%) was related to seed priming with gibberellic acid 50 ppm. Also, the highest seed vigor index (1836) was related to seed pretreatment with 50 ppm gibberellic acid. In all the applied salinity levels, the highest weight of mobilized seed reserve was obtained from seed priming with 50 ppm gibberellic acid. The highest seed reserve utilization efficiency from control seeds at 160 mM potential and the highest seedling dry weight and seed reserve depletion percentage in nonstressed conditions were obtained from seed priming with 25 and 50 ppm gibberellic acid. Seed germination improves triticale germination components under salinity stress conditions and increases the plant's tolerance to salinity against salinity stress in the germination stage.

IntroductionDurum wheat (Triticum turgidum L. var. durum) or hard wheat, is the second most important wheat crop species. Since durum wheat is mainly cultivated under dryland conditions in the Mediterranean region, its yield is strongly affected by abiotic stresses, especially drought and salinity. Salinity stress causes osmotic stress and disrupts the ionic balance of the cells and plant physiologic processes such as seed germination and seedling growth. This study was conducted to identify durum wheat salinity tolerant genotypes at germination stage using multi-trait selection indices such as multi-trait genotype-ideotype distance index (MGIDI) and the ideal genotype selection index (IGSI). Materials and methodsThe plant materials of this research were 50 different durum wheat genotypes, which were evaluated for salinity tolerance at germination stage. The experiment was conducted as a factorial in a completely randomized design with three replications. To create salinity stress, sodium chloride (NaCl) was used at three levels including 0 (control), 150 mM (~15 dS.m-1), and 300 mM (~30 dS.m-1) concentrations. To evaluate the salinity tolerance of the studied genotypes, quantitative stress tolerance indices were first calculated based on root (radicle) and shoot (plumule) dry weight under non-stress conditions (Yp) and average salinity levels (Ys) for each genotype. Then according to the results of factor analysis based on principal component analysis (PCA), the MGIDI index was calculated using the factor scores of the first two factors with eigen values greater than one. The IGSI index for each genotype was also calculated using all stress tolerance indices. Research findingsThe results of factor analysis based on principal component analysis (PCA) showed that the first two factors with eigen values greater than one explained 99.6 of the total variance. The calculation of the MGIDI index based on the factor scores of the studied genotypes showed that in average salinity stress conditions, genotypes 6, 23, 5, 30, 34, 29, 31, 2, 10, 39, 13, 9, 47, 12, 52, 48, and 1 with lower values of MGIDI (between 0.90 and 2.50) and higher values of IGSI (between 0.65 and 0.80) were the best genotypes in term of salinity tolerance. In contrast, genotypes 46, 43, 19, 26, 4, 15, 42, 38,11, and 37 with the lower values of IGSI and the higher values of MGIDI, were considered as weak and sensitive genotypes to salinity. The coefficient of determination (R2) between these two indices for all genotypes was 92%, indicating a high correlation between these two indices and the selection of same genotypes. ConclusionThe results of the present study showed that there was a significant genetic diversity among the studied durum wheat genotypes for salinity tolerance at the germination stage, which can be used in the breeding programs of this valuable crop. IGSI and MGIDI indices were also effective in identifying superior genotypes based on all stress tolerance indices. Therefore, these indices can be recommended to select salinity tolerant genotypes based on different traits in breeding programs.

Soil salinity is one of the environmental stresses that causes the accumulation of reactive oxygen species (ROS), and oxidative stress, and consequently, reduces crop growth and production. Antioxidative mechanisms are critical to protect cells from the adverse effects of ROS.

Thhis study was conducted in nutrient solution in Rice Research Institute of Iran, Rasht, Iran in 2019. The enzymatic activity and expression of effective genes on antioxidant defense were examined in two selected mutant genotypes (em3hs290 and em3hs84) tolerant to salinity stress, with Hashemi local cultivar, FL478 (tolerant) and IR28 (sensitive) genotypes. Biochemical traits including the activity of antioxidant enzymes, peroxidase, catalase, and ascorbate peroxidase, and the relative expression of genes encoding transcription factors (SNACI, DREB2B, and DREB2A) and genes associated with oxidative stress (OsAOX1C ،POX1، OsGR1، OsAPX2 and OsGPX1) were also measured and detected using real-time PCR technique.

The results showed that enzymatic activity of peroxidase (POX) in control cultivars (cv. Hashemi and IR28 cultivars) and ascorbate peroxidase (APX) in tolerant mutant genotypes and FL478 cultivar increased significantly. The genes expression associated with salinity stress tolerance also indicated that despite the variable behavior of the genes in the studied mutant genotypes, the expression of OSGR1, DREB2B, OsAOX1C and POX1  genes in studied tolerant mutants was more than susceptible cultivar. Transcript abundance of the OsAPX2 gene was significantly higher in salt-tolerant genotypes under short-term salinity stress and correlated with peroxide hydrogen removal and increased activity of ascorbate peroxidase enzyme.

The lack of similarity in the expression pattern of studied genes between the two salt-tolerant mutant genotypes (em4hs290 and em4hs84)  and  cv. Hashemi showed that the mutation could triger the salt-tolerance mechanisms in mutant genotypes, in comparison of cv. Hashemi, through emhancement of antioxidant enzymes activity in response to salt stress. It seemes that the mutant genotypes may have suitable growth in soil salinity conditions.

Cotton fibers, seeds, and stalks are widely used in the textile industry, food and feed products, and paper making. Salinity stress is a significant factor affecting the natural growth and development of cotton, limiting the cultivation of this strategic crop worldwide.

To investigate the effect of salinity stress on the population density of important cotton-sucking pests in salinity-tolerant cultivars, a two-year study was conducted using a completely randomized block design. Six salinity-tolerant cotton cultivars (Sahel, Sepid, Sinduz, 43200, Chokurova, and Siland) were evaluated with four replications in Golestan province. Each treatment or cultivar was planted in four plots, each plot consisting of 10 rows, each 11 meters long, with a row spacing of 0.8 meters and plant spacing of 0.2 meters. Data were collected on yield characteristics and population densities of key cotton-sucking pests, including thrips, whitefly, and cotton aphid. The treatments were then compared.

The data analysis showed no statistically significant differences among cultivars in terms of yield traits and cotton thrips pest population density. However, there were statistically significant differences in terms of cotton aphid and cotton boll weevil population densities per leaf at the 0.05% and 0.01% levels. Using Duncan's method, the comparison of aphid and whitefly population densities was significant at the 5% level. The highest population densities of thrips, aphids, and cotton boll weevils were observed in the Chokurova cultivar with an average of 0.5 per plant, the Sinduz cultivar with an average of 7.9 per leaf, and the Sinduz cultivar with an average of 2.6 per leaf, respectively. Conversely, the lowest population densities of cotton thrips, aphids, and whiteflies were found in the Sepid cultivar, with averages of 0.38 per plant, 4.5 per leaf, and 1.2 per leaf, respectively.

Among the salinity-tolerant cultivars selected in this experiment, the Sinduz variety attracted the highest number of pests. However, the Sepid variety demonstrated good growth and yield, high quality, and tolerance to sucking insects. These results suggest that the Sepid variety is a promising candidate for developing and managing cotton cultivation in saline areas.

Studying the genetic structure of populations and primary genetic reserves is one of the main priorities of maize breeding programs. Molecular markers are highly efficient in estimating the breeding value of genotypes. A total of 73 maize genotypes prepared from different research centers (Razi University of Kermanshah, Khorasan Razavi Agricultural and Natural Resources Research Center, Seed and Plant Improvement Institute (SPII) of Karaj, were evaluated in a completely randomized design with three replications under normal and salinity stress of 8 dS/m in pot conditions. Based on the results of analysis of variance a significant difference was observed between genotypes in most of the studied traits in each one of the conditions; which indicates the existence of high diversity between the studied genotypes. Estimation of breeding value for 25 traits in 73 genotypes in each one of normal and salinity stress conditions was performed using BLUP by exploiting kinship matrix calculated based on SNP molecular data. According to the sum of ranks of breeding values for all studied traits genotypes 17, 4, 8 and 3 under normal conditions, and genotypes 3, 17, W153R, 9, 4 under salinity stress conditions had the highest rank in view of breeding value. Also, P19 L7 Kahriz, P15L4, W37A, P6 L1 and P14L1 Kahriz genotypes under normal conditions, and P6 L1, P19 L7 Kahriz and P14L1 Kahriz genotypes under salinity stress had the lowest breeding values. In general, considering all the studied traits in two conditions, genotypes 17, 3 and 4 showed high breeding value and genotypes P19 L7 Kahriz and P6 L1 showed lower breeding value, respectively. Genotypes with high breeding value have the greatest potential in transmitting the value of traits to the next generation; therefore, they can be introduced as desirable parents to improve these traits in maize breeding programs.

Salt stress affects 20% of global cultivable land and is increasing continuously owing to the change in climate and anthropogenic activities. Globally, wheat is cultivated on non-saline and saline soils, covering an area of approximately 214.79 million hectares (Becker-Reshef et al., 2020). Salinity stress negatively affects the growth and development of wheat leading to diminished grain yield and quality. For this reason, it is important to develop effective strategies to improve yield through salt tolerance. The breeding of salinity-tolerant cultivars through selection and breeding techniques is one of the effective methods in the production and exploitation of saline soil and water.

In order to study the effects of salinity stress on grain yield, phenological and morphological traits and salinity tolerance indices among bread wheat elite lines, two separate experiments in a randomized complete block design with three replications were conducted in two saline and normal environments during two cropping years of 2019-2021. 20 wheat cultivars and elite lines cultivated at the South Khorasan Agricultural and Natural Resources Research and Education Centre. After determining the grain yield in both conditions, MP, GMP, TOL, HARM, STI and SSI indices were calculated and using SAS software, their correlation with grain yield was investigated and using STATISTICA software, the three-dimensional distribution of each cultivar and line was plotted. Combined analysis of variance was performed to determine the main and interaction effects in the two years of the experiment and the means were compared by Duncan's multiple range test at the level of 5% probability. Bartlett's uniformity test was performed before the combined analysis of variance. Analysis of variance and mean comparison was performed using SAS-9.0 software and cluster analysis was performed by Ward method through StatGraphics program.

The reaction of wheat lines were different in two environments and salinity stress reduced grain yield. The experimental results showed that different wheat lines react differently to salinity stress. Salinity stress decreased grain yield and morphological traits in all lines compared to normal conditions. Salinity stress shortens intermediates and reduces plant height and consequently leaf and shoot dry weight by reducing cell proliferation and reducing dry matter accumulation (Dura et al., 2011).The difference between cultivars and lines in terms of all phenological, morphological and grain yield in two years of the experiment was significant, which indicates the existence of appropriate diversity in the wheat elite lines. The existence of this genetic diversity can be very useful for selecting high-yielding wheat cultivars in salinity conditions. In the first year of implementation, Narin, line No. 3 and Barzegar with an average of 6494, 6227 and 6072 kg/ha, respectively, in normal conditions and Barzegar, line No. 18 and Narin with an average of 6361, 6166 and 5805 kg/ha respectively, had the highest grain yield under salinity stress. In the second year of the experiment, line number 16, 10 and 4 with an average of 5388, 5305 and 5155 kg/ha in normal condition and Narin, Barzegar and line No. 3 with an average of 4930, 4611 and 4180 kg/ha respectively, had the highest grain yield under salinity stress. Naturally, wheat lines grain yield under salinity stress was lower than their yield under normal conditions. Under these conditions, the plant leaf area of is greatly reduced, which reduces the photosynthetic capacity of the plant, and as a result, the amount of dry matter produced and ultimately the grain yield of the plant is reduced (Munns et al., 2002).

For selecting wheat cultivars and lines in the areas that are most exposed to salinity stress, YI, HM, GMP, STI, MP, RSI and YSI indices and in areas not exposed to salinity stress, MP and STI indices are suggested. Barzegar and Narin check cultivars and line number 10 were determined as the most tolerant and lines No. 14, 13 and 20 as the most sensitive lines to salinity stress by different indices. Cluster analysis of lines based on STI index led to the placement of Barzegar and Narin cultivars and lines No. 3, 4 and 18 in the first cluster in which the mentioned lines have fewer days to heading and in contrast more days to maturity, grain filling period, thousand-grain weights and higher grain yield.

Salinity can prevent the uptake of soil mineral ions due to the negative effect of sodium ions and disturbance of ion balance, but the use of Trichoderma biocompounds improves growth under salinity stress. To investigate the effect of four salinity-resistant Trichoderma strains on growth traits and mineral element uptake of eggplant seedlings under stress conditions, an experiment has been performed in a completely randomized factorial design with three replications in the greenhouse of Vali-e-Asr University of Rafsanjan during 2016-2017. The first factor is salinity in four levels including the control and concentrations of 8, 12, and 16 dS/m and the second factor is Trichoderma as T. aureoviride (T148-2, T189-4) and T. virens (T145, T133-1) as well as the control. The results show that under the influence of salinity, a significant decrease in growth traits takes place. At the highest salinity level, the average dry weight of roots and shoots is 50% and 72%, respectively. For stem diameter and seedling height, a 20% decrease is observed compared to the control. However, inoculation with Trichoderma improves these traits, resulting in a 1.6-fold increase in root dry weight (T142-8), a 2.7-fold increase in shoot dry weight (T133-1), and a 1.3-fold increase in seedling height (T189-4) in comparison to the control. The highest diameter increase could be observed in T142-8 strain by 38%. Using Trichoderma leads to significant changes in sugar, sodium, potassium, and calcium content. The results of this study show that Trichoderma can be a suitable biological agent to increase tolerance at high levels of salinity stress and improve the growth traits of eggplant seedlings.