جستجوی مقالات مرتبط با کلیدواژه "b" در نشریات گروه "زراعت"

Despite the previous reports on increased resistance of some crops to field dodder due to the application of silicon, this issue has not been studied on sugar beet. The current research was conducted in a factorial completely randomized design with five replicates in the late spring of 2023 in the Research Greenhouse of Bu-Ali Sina University, Hamedan, on sugar beet cultivar Shokofa. The first factor included silicon concentration at five levels: 1, 2, 3, 4, and 5 mM in sodium silicate. The second factor included the method of silicon application in three levels: seed pre-treatment, irrigation, and foliar application at 1, 3, and 5-leaf stages. Results revealed an interaction between the factors on the root and shoot dry weight of sugar beet and the dry weight and haustoria of field dodder. Each field dodder plant reduced each sugar beet plant's root and shoot weight by 48.6 and 40.1%, respectively. The traits measured in sugar beet and field dodder were not affected by seed pre-treatment with silicon. A negative relationship was observed between sugar beet dry weight and field dodder dry weight. Applying 1 mM silicon via all three application methods did not affect the traits measured in sugar beet and field dodder. By increasing the concentration of silicon irrigated and sprayed, the root and shoot dry weight of sugar beet increased, but the dry weight and haustoria of field dodder decreased. The lowest haustorium was observed by irrigating and spraying 5 mM silicon, resulting in a 50% reduction in the haustoria of field dodder. The irrigation application method had a relative superiority to the foliar application method. Therefore, by conducting additional experiments and confirming the results of this study under field conditions, the application of silica, especially through irrigation, can be a useful method to reduce the damage of dodder in the field.

International trade plays a vital role in the global economy, and the import of goods is one of its main pillars. Through the import of goods and services, countries can gain access to goods and services that are not produced domestically or that have high production cost. Sugar is considered as one of the country's strategic goods, and due to its high demand and consumption in recent years, the country has witnessed the import of this product. Dependence on the import of sugar and the inadequacy of its domestic production will cause any policy change in the import of this product to affect the welfare of many producers and consumers. Considering the close relationship between sugar import and food security of households, knowing the factors affecting the demand for sugar import becomes especially important for proper policy making in this sector. In this research, the factors affecting the demand for sugar import including the amount of sugar beet production, the amount of annual rainfall in the country, the world price of sugar and the gross domestic product, have been evaluated in the form of vector error correction model (VECM) in the period of 2011-2014. According to the obtained results, the amount of sugar beet production, the amount of annual rainfall in the country, and the global price of sugar have a significant and negative effect on the amount of sugar import demand. Sugar beet production is 1.89 units and has a negative and significant relationship with sugar import demand, which makes it important to increase productivity and support domestic production. The amount of annual rainfall of 3.24 units has a negative effect on the demand for sugar imports, which is the production theory in the economy. In other words, with the increase in the amount of inputs used in the production, the amount of production increase. Also, the world price of sugar is 0.91 units inversely related to the amount of sugar import demand, which is obvious and can be justified based on the law of demand. Finally, the GDP variable has a positive effect of 0.82 units on the amount of sugar imports, which indicates that during the period of economic growth and prosperity, the desire to import increases in the country and the per capita consumption of goods increases

Identifying the potential of the lands of each region is the basis for the implementation of cultivation pattern and the optimal use of environmental conditions. The main goal of this study was to identify the potential of agricultural lands in Lorestan province for spring sugar beet cultivation. In this research, the combination of network analysis process (ANP), fuzzy logic and geographic information system (GIS) was used. In total, 15 factors including six climatic factors, three topographical factors and six soil factors, were used to identify suitable potential sites for sugar beet cultivation. Thus, after transferring the criteria information to the GIS environment, their raster layer was prepared and then they were fuzzy based on the ecological needs of sugar beet with the help of fuzzy logic. In order to determine the weight value of each criterion, the ANP approach was used. Subsequently, the final layers were produced by combining weighted layers and were divided into four classes: very suitable, moderately suitable, marginally suitable and unsuitable. It was identified that 17.04% of the total studied area for sugar beet cultivation was located in very suitable area and 76.75% in moderately suitable area, and marginally suitable and unsuitable areas occupied 4.18% and 0.03% of the areas, respectively. From climatic factors: maximum temperature (27.02%) and effective rainfall (15.55%), topography: aspect (50.19%) and slope (18.55%) and soil: total nitrogen (99.99%), material Organic (100%) and available phosphorus (29.39%) created the greatest limitation (marginally suitable and unsuitable zone) for spring sugar beet cultivation in the studied lands

This study aimed to evaluate the environmental effects of sugar beet production systems in Razavi Khorasan province at different levels of nitrogen consumption (<200, 260-290, and >290 kg of urea per ha) using Life Cycle Assessment (LCA) during 2017 to 2022. To determine the number of growers, Cochran formula was used and consumption inputs were collected using using a questionnaire (50 fields). Life Cycle Assessment was calculated and determined in four steps: definition of goals and field of action, life cycle inventory analysis, life cycle impact and integration, conclusion and interpretation of results. The impact groups included acidification, eutrophication of aquatic and terrestrial ecosystems, and global warming. The functional unit was considered equal to one ton of root. In the final step, the ecological index (EcoX) was calculated. Cronbach's alpha coefficient was calculated to assess the reliability of the questionnaire. A second-degree polynomial function was used to evaluate yield response to urea levels. Results showed that with the increase of nitrogen consumption from less than 200 to 260-290 kg of urea per ha,  the root yield increased by 34% , so that the highest root yield with 92.59 t per ha was observed at 290-260kg urea level. The highest global warming potential for fertilizer level less than 200 kg of urea per ha was calculated as equal to 46.199 kg of CO2 equivalent to one ton of root. The highest amount of acidification, terrestrial eutrophication, aquatic eutrophication, and global warming groups for consumption of less than 200 kg of urea per ha was found to be equal to 59.0 kg SO2 per ton of root, 99.0 kg N2O equivalent per ton of root, 34.0 kg PO4 equivalent per ton of root, and 46.199 kg CO2 equivalent per ton of root, respectively. The main reason for N2O and NH3 emission was attributed to direct nitrogen fertilizer consumption. The highest normalization and eco-toxicity index belonged to the aquatic eutrophication impact category, calculated as 0.089 and 0.097 EcoX per ton of root, respectively

In this study, changes in biochemical traits and yield of different autumn-sown sugar beet cultivars treated with gamma ray irradiation under salinity stress condition were evaluated in Jafariyeh region located in Qom province in two crop seasons of 2018 and 2019. The experiment was conducted as a split factorial based on randomized complete block design with three replications. The main plot includes irrigation at two levels (normal water and saline water with electrical conductivity of 7000 to 10000 µmos cm-1) and sub-plots were combination of sugar beet cultivars (Sharif, Antek, and Eudoro) and gamma radiation (0, 50, 100, 200 and 400 Gy). Results showed that the activity of rubisco enzyme decreased in all three cultivars under salinity stress, however the highest level of rubisco activity under both normal and salinity stress conditions observed in Eudoro cultivar at 50 and 100 Gy levels. The concentration of malondialdehyde in Eudoro and Antek cultivars decreased by gamma radiation while increased in Sharif cultivar. In all three cultivars, the highest amount of chlorophyll content at 100 and 200 Gy gamma ray radiation levels was associated with an increase of 15-16% compared with control. Under salinity condition at 100 and 200 Gy levels, the highest average root yield was observed. Salinity stress caused a decrease in sugar yield in Eudoro, Antek and Sharif by 26.7%, 17.5% and 31.5%, respectively. Antek cultivar had a lower sugar yield than the other two cultivars. In general, Antek cultivar showed a higher yield and tolerance to salinity compared with other cultivars, and gamma ray irradiation had a positive effect on this tolerance

Preservation of the characteristics of the parent lines forming the hybrid variety through tissue culture leads to the stability and uniformity of the hybrid variety. In this research, in the first year, flowering stem parts were cultivated in in vitro conditions and produced shoots or clones. Then the propagated clones were transferred to larger pots in the greenhouse and also in the steckling field and vernalized in winter in Karaj. In the spring of the second year, the vernalized clones were transferred to the isolated field in Ardabil and planted in separate lines along with the pollinator parent roots of the hybrid that had already been prepared and vernalized and the hybrid seeds were harvested from the plants of tissue culture clones and cleaned. In autumn of the second year, the hybrid seeds obtained from two types of maternal parent clones along with the control cultivars were planted in the fields of three regions of Dezful, Darab and Gachsaran in an experimental design and required care and recordings were done. In June of the third year, the roots were harvested and quantitative and qualitative analysis was done at SBSI and the data were analyzed by variance. In the autumn of the third year, again the hybrid seeds obtained from two types of maternal parent clones along with the control cultivars were planted in the fields of two regions of Dezful and Gachsaran in an experimental design and required care and recordings were done. In June of the fourth year, the roots were harvested and quantitative and qualitative analysis was done at SBSI and the data were analyzed by variance. The statistical results during the two years of the yield trials showed that the tissue culture clone hybrid No. SBSI-51-1 with an average root yield of 99.10 tons per hectare, white sugar yield of 12.82 tons per hectare, and 1.44 % bolting compared to other experimental varieties has a significant advantage. In this research, for the first time, the seed of a commercial hybrid was developed from the cross between its pollinator parent and maternal male sterile parent (tissue culture clone), which had good yield and uniformity in the field.

Root rot is a serious threat for sugar beet production and consequently sugar industry. The most important way to deal with it is to use resistant cultivars. In order to identify and grouping new O-type lines resistant the fungus that causes rhizoctonia and crown rot root in sugar beet, 83 O-type lines along with three resistant control (Novodro and line SB-709) and a susceptible (bulk 191) lines were evaluated in microplot in Hamedan in 2023. Artificial inoculation was performed by propagating the Rh133 isolate with AG2-2 anastomosing group on corn seeds and placing next to two months sugar beet seedlings. At the end of the growing season, roots were harvested and evaluated using 1-9 scale, and the disease and harvest indices were calculated accordingly. In the present study, the average number of roots, disease index, and harvest index for the evaluated genetic mass were 17.16, 4.05 and 17.18, respectively. O-types 5 (OT 010245), 32 (OT 010277) and 80 (OT HSF-010041) obtained the highest number of roots and harvest index and lower disease index compared with other genotypes. Based on the SIIG index, it was found that O-types 36 (OT 010282), 32 (OT 010277), 5 (OT 010245), 80 (OT HSF-010041), 28 (OT 010273), and 1 (OT 010240) were adjacent to the ideal O-types in terms of the number of roots, disease index, and harvest index. Results of the cluster analysis classified the evaluated O-types into four groups. O-types 5 (OT 010245), 80 (OT HSF-010041), 32 (OT 010277) and 36 (OT 010282) were placed in a cluster that had significantly lower disease index and higher harvest index as well as SIIG index closer to 1 compared with other three groups. Also, the biplot analysis based on the first two components showed that O-types 80 (OT HSF-010041), 1 (OT 010240), 28 (OT 010273), 5 (OT 010245), 32 (OT 010277) and 36 (OT 010282) were placed in a suitable position of the biplot in terms of resistance indicators. Finally, O-types 5 (OT 010245), 80 (OT HSF-010041), and 32 (OT 010277) were identified as resistant maternal lines for future breeding programs.

Symbiosis with arbuscular mycorrhizal (AM) fungi often increases the tolerance of host plants against various stresses. Among abiotic stresses, salinity causes considerable loss in crop productivity. Comprehensive study of plant genotypes response to symbiosis with AM fungi and potential role of this relationship in improving the adverse effects of salinity and increasing plant tolerance would be effective in increasing crop yield. The present study aimed to investigate response of commercial barley varieties to mycorrhizal colonization under salinity stress.

In this experiment, six commercial barley varieties including Khatam, Golshan, Afzal, Aras, Makoui and Dasht were evaluated at two salinity levels of NaCl (0 and 150 mM) and two symbiosis levels including inoculated and non-inoculated with Funneliformis mosseae. A factorial design in a randomized complete block design with three replications was conducted under greenhouse conditions in Zanjan University, Zanjan, Iran. Five weeks after cultivation, barley plants were harvested and the traits related to fungal structures including total colonization rate, and the frequency of hyphae, arbuscule and vesicle were measured. Also, some physiological traits including shoot fresh weight, leaf relative water content (RWC), shoot Na+ concentration, shoot K+ concentration, and Na+/K+ ratio were measured.

The results of this experiment showed that there was a significant variation between barley varieties in terms of colonization rate and hyphae, arbuscule and vesicle frequencies of AM fungus. Also, salinity stress reduced the colonization rate, and hyphae and arbuscule frequencies of the fungus, but increased the vesicle frequency, which this reduction was more considerable in salt-tolerant varieties, Khatam and Afzal, especially in Afzal. The increase in vesicle frequency was also significant only in Makoui, Aras and Dasht varieties. The results showed that salinity stress reduced shoot fresh weight and leaf relative water content, and increased Na+ concentration and Na+/K+ ratio in all barley varieties, but these changes in Makoui, Aras and Dasht varieties especially in Aras were more than other varieties. On the other hand, colonized plants exhibit lower shoot fresh weight and leaf RWC compared to non-colonized ones. However, symbiosis enhanced leaf RWC in Khatam and Golshan varieties under non-stress conditions.

The results of this study showed that there was a significant difference between barley commercial varieties in terms of response to symbiosis with mycorrhizal fungus and response to salinity stress. Although the reduction of colonization rate may help barley plants to prevent the consumption of carbohydrate resources, the expected results of symbiosis in terms of improving barley plant growth or reducing the adverse effects of salinity stress on the plant was not observed in the present study. This indicates the complexity of the symbiotic relationship between plant and fungus, and environmental conditions especially stress conditions can increase this complexity.

Optimizing nitrogen fertilizer use is crucial for increasing efficiency and reducing its adverse environmental impacts in rice paddies. However, accurately predicting the timing of nitrogen requirements and effectively managing it in rice cultivation is challenging. Due to low nitrogen use efficiency and the difficulty in precisely forecasting plant needs, only 30-50% of the applied nitrogen is typically absorbed by the crop. Utilizing digital imagery to estimate the nitrogen content in rice leaves can aid farmers in managing fertilization by providing a relatively accurate assessment of the plant's nitrogen status. This approach requires establishing a relationship between the amount of applied nitrogen, the plant's nitrogen content, and the parameters of digital images. Therefore, given the importance of rice cultivation in Guilan and the necessity of optimizing nitrogen use, this study was designed and conducted to investigate the effect of varying nitrogen application rates on nitrogen content, leaf area, and biomass of Hashemi rice in Rasht.

This experiment was conducted during the 2016-2017 growing season as a randomized complete block design with three replications at the research farm of the Faculty of Agricultural Sciences, University of Guilan, on Hashemi rice. Seven nitrogen levels (0, 30, 45, 60, 75, 90, and 105 kg N/ha from urea) were applied as the experimental treatments. Transplanting occurred on April 30, with three seedlings per hill, spaced 20×20 cm apart, in plots measuring 3×2 meters. Samples were collected at various growth stages to measure plant nitrogen content, leaf area, and dry biomass. The data were analyzed using ANOVA, followed by Duncan's multiple range test for mean comparisons.

The analysis of variance revealed that increasing nitrogen application up to 45 kg/ha did not significantly affect plant nitrogen content compared to the control, while 60 kg/ha resulted in a significant difference compared to both 30 kg/ha and the control. Further increases beyond 60 kg/ha had no significant effect on tissue nitrogen content. The findings also indicated that the highest nitrogen content occurred at the tillering and booting stages, while the lowest was observed at the transplanting time. Nitrogen application also had a significant impact on leaf area, with the largest leaf areas recorded at 90 and 105 kg N/ha, and the smallest in the control, which showed no significant difference from the 30 and 45 kg N/ha treatments. The significant interaction effect of nitrogen application and sampling time on biomass indicated that the highest biomass was observed at 105 kg N/ha during the booting stage. Increasing nitrogen not only increased biomass but also altered the proportion of biomass accumulated at different growth stages relative to total biomass.

Overall, the findings of this study suggest that the optimal nitrogen rate for enhancing nitrogen content in rice tissues ranges between 45 and 60 kg N/ha. To achieve at least 95% of the maximum tissue nitrogen content, a minimum of 57.64 kg N/ha is required. This level of nitrogen application not only boosts nitrogen content and plant biomass but also plays a crucial role in improving efficiency and reducing nitrogen losses in rice paddies.

Transplanting in puddled soil is a common method of rice cultivation in the world, which requires high labor and cost. Therefore, this method is being replaced by direct seeding system in recent years. Although direct seeding system has many advantages, this method may change various aspects of rice plant cultivation. In this experiment, the effect of changing the cultivation method from transplanting to direct seeding on paddy yield and some grain quality characteristics of rice varieties was investigated.

This experiment was carried out based on split block design with three replications in Rice Research Institute of Iran (RRII), Rasht, Iran, in 2019. The studied factors were cultivation methods in two levels including transplanting and direct seeding, and rice varieties in five levels including local variety, Hashemi, and improved varieties, Kian, Anam, Gilaneh and Shirodi. The measured traits were paddy yield and grain quality characteristics including head rice, broken rice and milled rice percentage, crude and cooked grain length and width, grain elongation rate, amylose content, gelatinization temperature and grain protein content. For data statistical analysis, analysis of variance was performed using SAS software and comparison of means by least significant difference (LSD) test at 5% probability level.

The results showed that the effect of variety and cultivation method on paddy yield was significant, but their interaction was not significant. Comparison of means showed that paddy yield in direct seeding was about 200 kg more than in transplanting method. Shirodi variety with 7820 kg/ha had the highest yield, while there was not significant difference between other vraieties. Milled rice percentage was also more than in direct seeding than the transplanting method, ans the highest milled rice percentage was related to Shirodi variety in direct seeding system (71%), which was not significantly different from Shirodi variety in transplanting system (70%) and Gilaneh variety in direct seeding (70%). The percentage of head rice in direct seeding system (57.06%) was lower than that of transplanting system (65.86%). Among the genotypes, Shirodi and Kian varieties had the highest and lowest head rice percentage with 84.33 and 37.5%, respectively. Amylose content of all studied varieties increased in direct seeding system compared to transplanting cultivation, but this increase was significant in Anam, Gilaneh and Kian varieties, and not-significant in Shirodi and Hashemi varieties. The highest and lowest amylose content with 27.45% and 21.27% were also observed in Shirodi variety in direct seeding and Kian variety in transplanting cultivation, respectively. Changing the cultivation method from transplanting to direct seeding system led to a significant increase in the Alkali spreading value of Gilaneh, Shirodi and Kian varieties, but had no significant effect on the Alkali spreading value of Anam and Hashemi varieties. The highest grain protein content with 11.08% was observed in Anam variety in transplanting cultivation, which was not significantly different from direct seeding system (10.76%).

The results of this study showed that changing the rice cultivation method from transplanting to direct seeding had a significant effect on paddy yield and grain quality characteristics of the rice varieties, so that paddy yield and milled rice percentage were higher in direct seeding than transplanting, but head rice percentage in direct seeding was lower than transplanting system. One of the most important factors affecting the rice cooking quality is grain amylose percentage. According to the results of the current study, changing the cultivation method from transplanting to direct seeding did not increase the amylose content of Hashemi and Shirodi varieties, which have the largest cultivated area among the local and improved varieties in the northern rice-growing provinces of Iran, respectively. This results can be effective in the acceptance of direct seeding system by paddy farmers.

Physalis (Physalis peruviana L.) is a perennial plant belonging to the Solanaceae family, but it is grown commercially as an annual crop. Low temperature has been reported as one of the most restraining environmental factors for agricultural crops, particularly vegetables. Cold stress causes symptoms such as wilting, reduced growth and photosynthetic rate, chlorosis, necrosis, discoloration, abnormal ripening, increased susceptibility to diseases, ion leakage from cell membranes, and changes in respiration and ethylene production in plants. Amino acids are one of the possible approaches that induce cold stress tolerance in plants. Phenylalanine is one of the essential amino acids that is used as a nutritional enhancer, amino acid injection, and complex amino acid preparation. Foliar application of amino acids such as L-phenylalanine during plant growth increased anthocyanins and phenolic compounds contents in grape and strawberry fruits and cysteine also contains sulfur as an amino acid which is widely present in bacteria, yeast, plants, animals and certain single cells. Spraying amino acids on plants is one of the modern methods. Selenium (Se) and its salts protect plants against biotic (pathogens and herbivores) and abiotic (ultraviolet rays, heavy metals, arsenic) stresses. Also, the findings showed that selenium can effectively stimulate the phenylpropanoid metabolic pathway and it has been specifically determined that it protects plants against biological stresses.

In order to investigate the effect of low temperature stress during seedling growth stage, and foliar application of amino acids L-phenylalanine (Phe), L-cysteine (Cys) and sodium selenite (Se) on yield and fruit quality of Physalis (Physalis peruviana L.), an experiment was conducted in greenhouse and field of University of Zanjan. The seeds of physalis were sown in seedling trays contain peat moss. The seedlings were grown under normal conditions (25±2 °C/day and 20±2 °C at night with 60-65% RH). The different concentrations of Phe (0.75, 1.5 and 2.5 mM), Cys (0.25, 0.5, and 0.75 mM) and Se (0.25, 0.5, and 1 mg.L-1) was sprayed on the seedling at 4–5th true leaf stage and distilled water was used for control treatment. For the chilling stress treatment of seedlings, plants were transferred to the 4 °C climate chamber for 24 h and two days. The control group (plants without chilling stress) was grown under normal conditions (25±2 °C/day and 20±2 °C at night with 60-65% RH). Plants transplanted to the field and foliar sprayed three times (growth stage, flowering and fruit set stages) with amino acids and Se. Fruits were harvested with the change of calyx and fruit color from green to orange and total fruit yield estimated as a kg.ha-1. Also, chlorophyll and carotenoid contents of leaf, fruit carotenoid, titratable acidity, soluble solids contents, vitamin C ant antioxidant activity were investigated.

The results showed that low temperature significantly decreased total chlorophyll and carotenoid contents of leaves, titratable acidity (TA) and carotenoid contents of fruit, and caused increases in total soluble solid content of fruit, but had no significant difference on fruit yield, vitamin C content and antioxidant activity. Foliar application of Phe, Cys, and Se increased yield and fruit quality. The highest fruit yield (11419.1 kg.ha-1) was obtained in with application of Cys 0.5 mM in plants under low temperature stress. The maximum vitamin C content was obtained in plants sprayed with Phe 0.75 and 1.5 mM under normal condition. Also, the highest fruit antioxidant activity (56.9%) was observed with application of Phe 0.75 mM in plants without cold stress compared to other treatments and plants under stress. The beneficial role of Se and amino acids in increasing antioxidant capacity might be attributed to enhancing antioxidant enzymes activity, phenolic compounds and carotenoids content, which have antioxidant activity.

Therefore, the use of these compounds specially Phe 1.5 mM, Cys 0.5 mM and Se 1 mg.L-1 are suggested to improve the performance and quality of the fruit under low temperature stress or non-stress conditions.

Salinity affects about 1.7 million hectares of agricultural land in Iran, which poses a serious challenge for wheat production, as the most strategic crop in the country. Therefore, identifying wheat genotypes with salinity tolerance and selecting effective traits for accelerating the breeding process are crucial objectives.

The experiment was aimed at assessing the response of 12 wheat cultivars to different levels of salinity using NaCl concentration as salt stress at early seedling stage under hydroponic conditions. A factorial experiment based on randomized complete block design with three replications was conducted at the research greenhouse of the Agriculture Faculty, University of Zabul, during the 2020 cropping seasons. 12 wheat cultivars (Shiraz, Falat, Durum, Gascogne, Mahdavi, Alvand, Cross Azadi, Roshan, Star, Tous, Hirmand and Cross Bolani) were irrigated with four concentrations of NaCl (0, 100, 200 and mM). The physiological and biochemical traits of wheat cultivars, including seedling fresh mass, ascorbate peroxidase, glutathione peroxidase, catalase, proline, sodium, potassium, and potassium to sodium ratio (K+/Na+) were recorded at four weeks after seed germination.

The results showed that the amount of ascorbate peroxidase, glutathione peroxidase, catalase, proline and sodium in the leaves of wheat seedlings were increased with an increase in salinity level. In contrast, the seedling fresh mass, potassium content and K+/Na+ were decreased with an increase in salinity level. The increase of ascorbate peroxidase, glutathione peroxidase, and catalase activities, representing the main enzymatic H2O2 scavenging mechanism in wheat cultivars. In NaCl treated seedlings, Falat, Mahdavi and Cross Bolani cultivars showed higher ascorbate peroxidase than other cultivars tested. In contrast, high level of catalase was recorded in Alvand cultivar. In the other hand, maintain the high level of proline and potassium to sodium ratio are the main mechanisms for tolerance to salinity in Shiraz and Roshan cultivars, respectively. Wheat cultivars showed different response to the increase in salinity level, while in Roshan, Mahdavi, Hirmand and Cross-Bolani cultivars, the increase in salinity level had less effect on the seedling fresh mass than other cultivars, but different patterns of changes in physiological and biochemical traits were observed in these cultivars. Salinity resistance in Mahdavi cultivar was directly related to the increase of ascorbate peroxidase and catalase, but on the other hand, in Roshan cultivar, salinity resistance was related to maintaining a high level of potassium to sodium ratio. Potassium uptake is vital for plant growth but in saline soils because of their shared transport system and physicochemical similarities, the sodium in the soil solution competes for uptake with potassium and can lead to potassium deficiency. The induced potassium deficiency inhibits growth because it plays a critical role in maintaining cell turgor, membrane potentials, and enzyme activities. In salt-tolerant cultivars of wheat such as Roshan, under salt-stress conditions, limiting sodium uptake and preventing potassium losses from the cell may help to maintain a potassium to sodium ratio in the cytoplasm that is ideal for plant metabolism. Accumulation of high amounts of proline is often related with the salt tolerance nature of crop cultivar and high proline accumulation in the salt–tolerant cultivar than in their salt–sensitive are reported previously. The regression coefficients indicated that seedling fresh weight (R2=0.89), potassium (R2=0.86) and the ratio of potassium to sodium (R2=0.69) were the most reliable predictors of the effects of increasing sodium chloride concentration. These variables accounted for a large proportion of the variance in the response variable and had significant p-values.

According to the results of this experiment, it can be concluded that seedling fresh weight, potassium, and the ratio of potassium to sodium are more suitable criteria for selecting among cultivars under salt stress conditions.

Abiotic stresses can disrupt future food security, which simultaneously implies the importance of genotype screening in stressed environments. Drought and phosphorus stresses have great effects on the growth and development of maize. Soil dryness and phosphorus deficiency cause similar effects and illicit similar defence mechanisms in plants (Xia et al., 2021a). Drought and phosphorus stresses in the root zone can cause active oxygen accumulation in plants. In order to deal with excessive accumulation of active oxygen, plants activate their oxidative defence mechanisms through enzyme or non-enzymatic routes. Oxidative stress caused by excessive accumulation of reactive oxygen species is one of the important physiological factors affecting plant growth and development under stress conditions. The sensitivity of genotypes to water deficit is different and they can be classified into two groups, tolerant or sensitive. Maize (Zea mays L.) is one of the most important crops in the world for food security, as it feeds millions of people. Abiotic stress can create significant challenges in maize production. The present study aimed to determine the effects of phosphate and PEG stresses on the physiological and biochemical traits in the maize cultivars.

Measured traits in leaf and root tissues were analysed among five maize cultivars under PEG and phosphate stresses. Also, analysis of biochemical traits such as chlorophyll a/b and carotenoids in maize seedlings under PEG 20% and low phosphate were analysed. The five maize cultivars were exposed to PEG 20% and low phosphate stresses and sampled at two-time points after treatment (24 and 48 h). This experiment was carried out as a factorial experiment in the form of a completely randomized design with three replications. In this study, antioxidant enzymes such as catalase, ascorbate peroxidase, and peroxidase activity were measured in leaf and root tissues. Further, PCA, dandraogram and correlation of physiological traits, biochemical and morphological traits were analysed. Statistical analysis was performed using SPSS. Differences across tissues were analysed using one-way ANOVA. Duncan’s test was used to compare the treatment means at P<0.05. Values represent the means of three replications per treatment. Principal Component Analysis (PCA) and correlations were performed using SPSS 22.

Based on the cluster analysis, the cultivars were grouped into three classes. The cluster I included Fajr, Paya, and Dehghan whereas, Kosha and Taha cultivars were placed in the clusters II and III, respectively. Also, there was a significantly positive correlation at the probability level of one percent between the content of chlorophyll a/b and root anthocyanin and total chlorophyll content. Correlation between biochemical and physiological traits is shown in Figure 2. The chlorophyll a showed a positive and significant correlation with total chlorophyll and carotenoid contents. The chlorophyll b showed a positive and significant correlation with total chlorophyll content and root anthocyanin. PCA was performed on physiological and biochemical traits to fully investigate the various factors that play essential roles in the drought indices. The cumulative contribution rate of the total changes of PC3 reached 97%. According to PCA analysis measured by correlation matrix and biplot analysis method, it was found that these parameters can be used to evaluate the response of maize genotypes to abiotic stresses under different environments. The relationships between biochemical traits and genotypes is shown graphically in two segments of PC1 and PC2.

Principal component analysis (PCA) and measured traits showed that Fajr, Paya, and Kosha cultivars can show high performance under studied stress conditions. In the present study, the Kosha cultivar was shown to be relatively water stress and low phosphate tolerant due to improved antioxidant, chlorophyll, and carotenoids activities under abiotic stresses.

Oilseeds are the second main source of human food after cereals. Safflower is an oilseed crop with favorable and unique characteristics that make it a valuable oilseed crop. Safflower due to having long roots and the high ability for absorbing water from deep soil layers, is considered as a low water-tolerant plant; but after the rosette stage, it becomes more sensitive to water stress such that since the first signs of inflorescence emergence up to the middle of the grain-filling period, it shows more sensitivity to this kind of stress. Increasing need for oil production on one hand and increasing levels of drought due to world climatic changes on the other hand makes it necessary to seek for more water stress tolerant plants such as safflower with relatively high yield capacity under low water content areas. Meanwhile the area under cultivation of safflower should increase. Agricultural and environmental factors can affect safflower seed yield and seed oil content. Therefore, it is important to investigate different environmental factors and their effects on growth and yield performance of safflower plants. Limitations of water resources makes it more difficult to grow safflower plants. Furthermore increasing levels of per capita oil consumption in Iran indicates that oilseed production must increase. Therefore, One of the objectives of this research was to identify and evaluate species and cultivars resistant to water stress and to find the plant stages sensitive to water stress.

In order to evaluate the effects of water stress on some morphological, yield and yield components of different safflower cultivars, an experiment was carried out as split plots based on randomized complete blocks design with three replications at the experimental field 56° 58' E; 30° 15' N; 1754 meters above sea level of Faculty of Agriculture, Shahid Bahonar university of Kerman, Iran during 2019-2020 growing season. Water stress applied at three levels including 40, 60 and 100% of full crop water requirement in the main-plots and 6 Iranian safflower cultivars including Faraman, Goldasht, Golmehr, Parnian, Padideh and Sina assigned to the sub-plots. Physical and chemical properties and nutrient elements content of the soil before planting were measured using samples taken from of 0-30 cm soil depth of experimental location. Seeds planted manually and plots fully irrigated immediately after planting. Thereafter, plants irrigated throughout the growth period based on the calculated values of the water requirement of the plant.

Based on results, the treatment 40% of the plant water requirement had a significant reduction effect compared to other treatments of water stress on the studied traits in all investigated cultivars. The results Data analysis showed that water stress had not a significant effect on lateral branch number, but it causes a significant reduction in all traits, Including the plant height, number of heads per plant, number of seed per head, head diameter, 1000 seed weight, seed oil content, oil yield and seed yield. Significant differences found among cultivars in term of all other plant characteristics. Meanwhile, Highest values of 1000 seed weight (37.2 g), oil yield (461.8 kg.ha-1) and seed yield (1592.6 kg.ha-1) observed in Faraman cultivar. The Interaction effects between irrigation treatment and cultivar were significant in case of number of heads per plant, number of lateral branches, oil yield and seed yield. However, the Faraman cultivar had more grain yield potential in water stress conditions than the other investigated safflower cultivars.

Generally, results showed that the reaction of the six cultivars investigated in terms of plant height, number of heads per plant, number of seed per head, number of lateral branches, 1000 seed weight, head diameter, seed oil content, oil yield and seed yield were affected by water stress. The highest values of 1000 seed weight, oil yield and seed yield among the investigated safflower cultivars were related to Faraman cultivar. Meanwhile, cultivar Faraman showed higher seed yield potential under water stress conditions compared to the other cultivars. Therefore, to achieve higher yield, Faraman recommended to be grown under low soil water content condition.