نشریه علوم سبزی ها
سال ششم شماره 2 (پیاپی 12، پاییز و زمستان 1401)

In recent years, young quinoa leaves are used as fresh or cooked vegetables. Due to its high quality vegetable protein, quinoa is a promising candidate for increasing food production in the world. Due to its tolerance to abiotic stresses, quinoa is known as one of the most valuable and nutritious food products. Environmental stresses, especially drought and salinity are one of the most important factors in reducing growth in plant growth and development stages, especially the germination stage of the plant. The increase in global demand for the production of nutritious and healthy food has challenged researchers to look for the production of products in marginal areas that are inefficient for producing agricultural products due to adverse weather conditions, low soil fertility, and lack of good quality irrigation water. As a result, in this study was conducted to study the effect of selenium and humic acid on germination percentage, seed germination characteristics and some morphological characteristics of quinoa (Chenopodium quinoa) seedling under drought and salinity stress as a factorial experiment in the form of completely randomized design with three replications.

The research was conducted as two independent experiments. The experiments were  carried out in the physiology laboratory of the Faculty of Agricultural Sciences and Engineering. The first experiment consisted of four levels of selenium (0, 5, 10 and 20 mg L-1 sodium selenate), three levels of humic acid (0, 100 and 300 mg L-1) and four levels of drought stress (0, -4, -8 and -12 bar). The second experiment with four levels of selenium (0, 5, 10 and 20 mg L-1 sodium selenate), three levels of humic acid (0, 100 and 300 mg L-1) and six levels of salinity stress (0, 0.5, 4.3, 8, 11.8 and 16 ds/m) were performed. Titicaca variety was used in this research. The criterion for seed germination was the emergence of roots approximately 3 mm long. At the end of the seventh day, the characteristics of germination percentage, germination rate, mean daily germination, mean germination time, germination rate coefficient, seed vigour and seed germination index were measured. At the end of the experiment, the length, fresh and dry weight of seedlings, stems and roots were examined.

Drought and salinity stress had a negative effect on germination percentage and seed  germination indices and morphological characteristics of quinoa seedlings. Whiles, according to the results, selenium and humic acid under salinity and drought stress had a positive effect on germination percentage and some morphological characteristics of quinoa seedling. Considering that one of the salinity resistance indicators is having longer root length, selenium and humic acid increased the root length of quinoa under salt stress conditions compared to the control. Humic acid and selenium had a positive effect on germination and plant growth by increasing water uptake and root volume, so that the highest germination percentage and morphological characteristics in the treatment without stress with 20 mg L-1 sodium selenate and 300 mg L-1Humic acid was observed. According to the obtained results, the highest percentage of germination, germination rate germination rate coefficient, seed vigor, seedling, stem and root fresh weight in the treatment without salt stress with 20 mg L-1 of sodium selenate and 300 mg L-1 humic acid was observed. With the increase of sodium chloride concentration, the germination percentage and germination indices of quinoa seeds decreased. Under salinity stress, in all four levels of selenium, with increasing humic acid concentration, the percentage of germination and investigated characteristics increased.

Therefore, the use of humic acid at a concentration of 300 mg L-1 along with 20 mg L-1 sodium selenate is recommended to improve germination and seed growth of quinoa under drought and salt stress conditions. As a result, the use of selenium and humic acid in the direction of sustainable agriculture and healthy crop production is cost effective and the use of selenium and humic acid fertilizer is recommended. Humic acid improves product performance by increasing nutrient absorption and affecting antioxidant defense mechanisms. In salinity stress, humic acid leads to osmotic regulation by maintaining water absorption. Selenium has beneficial effects on plants at low levels. Selenium can affect germination and root length. Plant seeds are able to absorb selenium from the environment and convert it into various organic forms or inorganic selenium compounds during germination.

Fresh cucumber fruits are perishable and their quality is impacted by abiotic stresses. During postharvest life, due to internal and external factors, chemical and physical changes occur in fresh fruits, which may result in serious losses in nutritional quality. Chilling injury (CI) as an abiotic stress during storage of vegetables, also mostly increases susceptibility to decay, leads to economic losses. Salicylic acid (SA), a natural and safe phenolic compound, has been found to generate a wide range of metabolic and physiological responses in plants and exhibited a high potential in controlling postharvest losses of horticultural crops. The mechanisms of SA treatment in alleviating CI were extensively, which could be attributed to enhancing membrane integrity and antioxidant system activity. The goal of this study were to examine the effects of SA on controlling postharvest CI of cucumber fruit, with investigate the chlorophyll fluorescence by SA in reducing damage on cell membranes integrity in relation to chilling injury of the cucumber fruit during cold storage preservation.

This study is a factorial experiment in a completely randomized design in three replications in private greenhouse located in Marand city in mid-August 2017. The factors of this experiment was the different concentrations of salicylic acid (0, 0.25, 0.5 and 1 mM) and distilled water during (0, 6 and 12) days of storage, pre-storage and post-storage on greenhouse cucumber of Nagin variety were studied on fruit weight loss, total soluble solids (TSS), amount of fluorescence chlorophyll, ion leakage, rate of frost damage. Traits were evaluated before, between and after storage. In order to investigate the effects of storage of fruits, they were transferred to the refrigerator, and after 12 days of storage with comparison of the fruits of treated plants with control fruit, Effects of pre-harvest salicylic acid foliar application on Cucumbers were evaluated for exposure to chilling.

The results showed that different salicylic acid levels were effective in reducing fruit weight, and the highest weight loss (6.64%) was observed in distilled water treatment. The effect of SA treatment in reducing weight loss of fruits might be due to the fact that SA suppressed the transpiration of cucumber fruit by closing stomata of the treated fruit. In this experiment fruit treated with SA developed significantly lower chilling injury than control fruits. The suppression effect of salicylic acid treatment in SA treated cucumber fruit might be due to delaying the ripening process and lowering the incidence of chilling injury. The highest soluble solids (3.25 Brix) were achieved in the middle part of storage in 0.25 mM of SA treatment fruits and the lowest TSS (1.38 Brix) was observed before storage in 0.5 mM SA. The highest levels of Fv/Fm (0.81) was observed in middle of the storage (0) and control treatment and the lowest (0.67) in post storage (1 mM). Therefore, storage had a negative effect on the chlorophyll fluorescence index. A significant decrease in Fv/Fm, implying suppressed photochemical activity, for cucumbers stored at chilling temperatures of 4°C and 7°C, compared to those at 10°C and 13°C.The highest level of chilling damage in control treatment (distilled water) and the lowest was in the level of 1 mM salicylic acid. The highest level of ion leakage was in the treatment with distilled water, and the lowest level was at the level of 0.5 mM salicylic acid. An increase in ion leakage indicates leakiness of ions due to a loss of membrane integrity. This is an inherent feature of plants which are exposed to stresses such as low temperature.

Cold storage preservation induced chilling injury in cucumber fruit. The results showed that pretreatment with salicylic acid at a concentration of 0.5 mM can be commercially effective to improve the parameters of weight and performance, growth and protection from stress. The use of salicylic acid, which is known as an internal signal molecule, is mainly discussed in the tolerance of natural stresses in plants, can increase the plant's resistance to stresses and improve the growth and development of plants. These results suggested that SA as a postharvest tool could effectively alleviate chilling injury and enhance chilling tolerance of cucumber fruit. However, further studies are needed to explore the commercial use of SA in alleviating CI of cucumber fruit.

Microgreens are immature vegetables with green leaves that can be harvested and consumed shortly after the appearance of the first true leaves. Basically, the part that appears above the root is used as a fresh vegetable for salads. They are more nutritious than their adult plants. In this study, basil (Ocimum basilicum) seeds were used to produce microgreens. Pythium spp. such as Pythium ultimum is one of the diseases that limits the cultivation of many microgreens.

Ten endophytic bacteria were isolated from the roots of some adult plants of the Lamiaceae family (including basil, Phlomis aucheri and rosemary). Basil seeds were disinfected with 1% sodium hypochlorite for two minutes and then washed five times with distilled water and dried at room temperature. For each treatment, 20 seeds with three replications were placed in two layers of sterile filter paper inside petri dishes and transferred to an incubator with a temperature of 21 ° C and a humidity of 65 to 70%. In the initial pretest to select the best bacteria in terms of growth stimulus characteristics, three traits of germinated seeds percentage, seedling height and wet weight at a common bacterial concentration (5×107 cfu/ml) were evaluated. Antifungal activity against P. ultimum was performed in mix of PDA and NA medium. Bacterium was detected using 16S rRNA region primers: 27F and 1492r. Several growth factors and biochemical changes including total phenol, peroxidase and catalase were investigated.

None of the bacteria showed a direct antifungal effect against P. ultimum in the laboratory. Among the bacteria, isolate GF1 showed more effects of growth stimulation than other bacteria. All growth traits showed a significant increase in the level of 5% probability in both bacterial isolate GF1 concentrations compared to the control, so that the least observed changes in the increase of each growth factor was above 50%. The highest increase in both concentrations was related to seed length vigor and germination vigor. In some cases, a significant difference was observed between the two concentrations of GF1 isolate. None of the bacteria showed a direct antifungal effect against P. ultimum in the laboratory. Sequencing of 16S region of ribosomal genes showed that the bacterium is Rhizobium sp. . This bacterium (in two concentrations of 5×107 and 5×106) had a significant effect of improving the weight loss of microgreens, the disease severity and disease incidence caused by P. ultimum in comparison with the control. Biochemical analysis showed that total phenol, catalase and peroxidase were significantly increased in microgreens inoculated with this bacterium. The results related to changes in total phenol, catalase and peroxidase after 14 days and at the same time with microgreen harvest showed that the bacteria in both concentrations were able to increase the amount of total phenol and defense enzymes in the microgreens. The concentrations used by the bacteria showed a significant difference in all cases, but the low concentration was also able to increase the amount of total phenol and enzymes compared to the control. Changes in total phenol, catalase and peroxidase in almost all cases from highest to lowest included the following treatments: high concentration of bacteria and fungus, low concentration of bacteria and fungus, high concentration of bacteria, low concentration of bacteria, fungus alone and the control which did not contain any microbial treatment. However, in the case of catalase, the changes resulting from inoculation of the pathogenic fungus alone and the changes resulting from the use of bacteria at lower concentrations were almost equal and did not show a significant difference.

In this study, unlike many similar studies that aim at biological control. The initial screening of bacteria with useful potential in agriculture was not based on antifungal properties. Rather, the primary goal was to increase germination and microgreen growth factors. Since the goal of biological control is ultimately to increase efficiency of crop yield by disease control, it makes sense to prioritize growth-promoting characteristics that directly affect the efficiency. This study showed that the endophytic bacterium, Rhizobium sp. GF1, without direct antifungal effect using inducing resistance mechanism and increasing the plant's defense compounds is able to significantly control the disease. In this study, bacterium was obtained that have a dual useful ability in the fields of plant protection and vegetable growing.

Microgreens, are tender seedlings produced from seeds of different species of vegetables, aromatic herbs and herbaceous plants, including wild edible species. Microgreens are generally harvested 7-21 days after germination, when cotyledonary leaves are fully developed, with or without the emergence of a small pair of trueleaves. Increasingly used by chefs as edible garnish, microgreens are becoming popular also for their high content of bioactive compounds. Moreover, with the development of the urban farming industry there is increasing interest in their commercial production. Despite the short growing cycle, the commercial production of microgreens requires particular attention, and the choice of the growing medium and optimizing light intensity and quality represents one of the most critical aspects of the production process. They are recognized as health-promoting foods because of containing high phytonutrients and bioactive compounds such as phenolic compounds, flavonoids, pigments, vitamins and trace minerals (Xiao et al., 2012). Compared to fruit and other vegetables, they contain higher phytonutrients per calorie. Moreover, many phytochemicals also have medicinal properties playing important roles against various diseases such as stroke in the brain, cancer and Cardiovascular diseases and strengthening the immune system.

Experiments were performed at the horticultural department of university of Mohaghegh Ardabili, radish seeds were evenly broadcasted on the surface of the growing media (soil or coco-peat) in each tray. Seeds were kept under dark condition for 3 days. Every day trays were sprayed two times with deionized water. After germination, trays were subjected to different light quality conditions (red, blue, white and natural light). Air temperature ranged between18 to 20 °C. At the first appearance of the first true-leaves, 10 days after sowing, microgreens of each tray were harvested by cutting the seedling just above the surface of the growing media with a sterilized knife. Morphological and physiochemical traits including yield, height, leaf area, chlorophyll, phenolic compound, carotenoid and flavonoid content, antioxidant activity, peroxidase and ascorbate peroxidase were evaluated with 5 replications.

Results showed that light quality and media affects growth, physiology and nutritional value of the radish microgreen. Radish microgreen also performed differently in different growth media. According to the results there was significant difference among media and light treatments with respect to yield, height and leaf area. In microgreen production yield depend on plant height, leaf area and planting density and the quality of microgreens depend on their nutritional value, antioxidant activity and exterior appearance. According to the results, seedling grown in trays filled with garden soil performed better with respected to quality and yield compared to coco-peat. Plant grown under blue and red light showed more chlorophyll, carotenoid, phenol and flavonoid content, however plant grown under natural light condition showed more antioxidant activity and leaf area. There was a positive and significant correlation between leaf area and yield per area, while the correlation between plant height and yield was not significant. So in microgreen production any treatment that affect leaf area might be recommended for better exterior look and its yield. The highest chlorophyll, carotenoid, phenol and flavonoid content achieved in plant grown under blue and red light. Moreover, the highest antioxidant enzymes activity of peroxidase and ascorbate peroxidase measured in plant grown under blue light. As there was a positive and significant correlation between enzyme activity and chlorophyll and carotenoid content, so it might be concluded that blue and red light induce chlorophyll and carotenoid production in microgreens. There was also a high correlation among plant height, enzyme activity and chlorophyll and carotenoid content.

As described above, in microgreen production the quality of microgreen depends on seedling height, greenness of the seedling leaf, leaf area, and nutritional value and so on. It is better to use combination of light sources to produce more marketable microgreen with high quality. Moreover it is recommended that any media with no or low mineral element should be mixed with organic or inorganic compound to produce high quality microgreens.

Broccoli (Brassica oleracea) belong of the Brassicaceae family, contains high levels of bioactive compounds, such as vitamin C, phenolic compounds, and glucosinolates. These nutrients have antimicrobial, antioxidant and anti-cancer properties. However, broccoli can usually be stored for several days during transport or at the time of sale in the store or after purchase by consumers. During this period, their flowers start to turn yellow and their nutritional content decreases rapidly. In order to delay the aging stage in broccoli, various methods such as changing the atmosphere of the storage place, irradiating red light, the effect of plant hormones and treating chemical compounds can be used to maintain the appearance quality of broccoli and delay the aging stage. Various chemical compounds have been used to delay the aging stage in broccoli, but choosing a compound that has the least harmful effect on human health is one of the main priorities of scientists active in this field. One of these chemical compounds that has the least negative effects on health is melatonin. The purpose of this study is to investigate the effect of melatonin treatment on physiology after harvesting broccoli during storage.

In a primary experiment, broccoli was treated with 10, 25, 50, 100, 250, 400 and 600 μmol/L melatonin. Primary test results showed that 100 μmol/L melatonin had a significant effect on post-harvest appearance quality. Therefore, the 100 μmol/L melatonin treatment was used as a reference for more extensive studies in this paper. In this study a factorial experiment was conducted using a randomized completely design with three replication. Broccoli was divided into control and treatment groups, and after 20 minutes immersion in 100 µmol L-1 as treatment and distilled water as control. Then it was kept at a temperature of 4±1 °C for 4 weeks. In this research, the indicators of weight loss percentage, content of photosynthetic pigments, the activity level of antioxidant enzymes, the content of free radicals, and the amount of phenolic, flavonoid, vitamin C, and glucosinolate in weeks 0, 1, 2, 3 and 4 were evaluated after storage and with three repetitions.

The results of this research showed that broccoli treatment with melatonin was more effective in maintaining fresh weight during storage than the control. In the first to fourth weeks, the percentage of weight loss in the control group was 1.26, 1.57, 2.19 and 2.23 times higher than the melatonin-treated group, respectively. The results indicated that there was a significant difference (p<0.05) in the content of chlorophyll a and b in different weeks of storage between the control and the melatonin-treated groups. The melatonin treatment can increase the content of chlorophyll a, b and total chlorophyll by suppressing the activity of chlorophyllase enzyme. So that, melatonin treatment led to a decrease in chlorophyllase enzyme activity, and this decrease in the fourth week in the melatonin-treated group was about 47.8% less than the control group. The results indicated that there was a significant difference (p<0.05) in the content of vitamin C and glucosinolate between control and the melatonin-treated groups in during storage. Compared with control group, significantly higher total phenolic content was observed in the melatonin treated group in during of storage. Comparison of means showed that the content of flavonoids in broccoli treated with melatonin showed a general increasing trend, so that in the fourth week, the content of flavonoids in the treatment group was 3.67 times that of the control group. Measuring the activity of antioxidant enzymes showed that melatonin treatment was able to reduce the content of superoxide free radicals by increasing the activity of superoxide dismutase enzyme, so that in the group treated with melatonin, SOD activity increased by 35% and 47.6% in the third and fourth weeks, respectively.

In general, the effect of melatonin on broccoli is associated with increasing the activity of antioxidant enzymes and suppressing the activity of chlorophyll-degrading enzymes, which reduced the content of reactive oxygen species and increased the content of chlorophyll. Based on the data obtained in the present study, as a result of the increase in phenolic and flavonoid compounds, antioxidant enzymes and also antioxidant compounds such as vitamin C and glucosinolate, it improves the quality of broccoli. Generally, it seems that postharvest treatment with melatonin can be a useful method to maintain the appearance as well as the quality and nutrient levels of stored broccoli and increase its useful life.

Potato (Solanum tuberosum L.) is one of the main crops for food security in the world. This plant has a cultivated area of more than 16 million hectares and a production of 360 million tons per year. This plant is propagated sexually (true potato seeds (TPS)), and asexually (tuber formation), but for commercial purposes mainly seed tubers are used. Mini tubers are used to prevent diseases and pests and increase product yield. Recently, microtuber is widely used as starting material for the propagation of potato due to its privileges including germplasm conservation, high storage potency, unseasonal production, decontaminated propagation, easier acclimatization and handling, rapid and economical multiplication procedure, and maximum yield productivity. Several factors affect potato microtuber growth, which can be mentioned as light quality, sucrose, genotype, plant growth regulators, explant type, gelling agent, and nutrition. The positive efficacy of controlled stressful conditions on enhancement efficiency of in vitro geophyte production was reported. According to crucial effect of temperature on tuberization, the purpose of this research is to investigate the role of thermal stresses (heat and cold) on microtuber induction under in vitro circumstances.

A single node of a greenhouse-grown stem was used as an explant for this experiment. We used ‘Sante’ cultivar as a model plant in this experiment. This research has three phase including explant preparation, plantlet multiplication and temperature stress pretreatments to induce microtuberization. Explants were disinfected with sodium hypochlorite 1% with 1 ml Tween® for 20 min. For multiplication phase, explants were cultured in MS medium contained 30 gr/l sucrose and 7 gr/l agar. Also, plantlets were cultured in MS medium with 80 gr/l sucrose for microtuberization phase. Explants were placed at several cold conditions (1, and 4 ºC) in three duration (4, 8, 12 h) and also hot circumstances (25, 40, 45, and 50 ºC) with different duration (0.5, 1, 2 h) in contrast to control treatment (25 ºC). The explants were placed under long photoperiod (16:8 hours) with fluorescent light (PAR = 750 s-1 m-2). Following 60 days, explant fresh and dry weight, explant diameter, microtuber diameter, microtuber fresh and dry weight, biomass, microtuber fresh weight per glass, microtuber number per glass, tuberization degree, and tuberization percentage were recorded.

The results illustrated that explant fresh weight and explant diameter increased in response to heat stress compared to control treatment. Based on our results, the highest explant fresh (58.4 gr) and dry weight (33.3 gr) was observed in 50 ºC (0.5 h) and 4 ºC (12 h), respectively. Furthermore, explant grown under 45 ºC for 2 hours had the greatest explant diameter (1.46 mm) in contrast to the rest. The most tuber diameter was observed in explants placed under 4 ºC for 8 h with 3.6 mm. Explants treated with 4 ºC for 8 h had the uppermost fresh weight and dry weight of microtuber with 45.3 gr and 9.5 gr, respectively. In biomass trait, the lowest amount was related to the control treatment, which indicates the significant effect of stress on improving biomass. Among the stress treatments, explant 1 °C for 12 h had the greatest effect in increasing biomass. In microtuber fresh weight per glass, 1 °C for 8 h treatment had the maximum effect with 160 gr. Also, hot treatment had a positive effect on tuberization degree. The most tuberization degree (4) was fond in explants treated with 50 for 2 h. Furthermore, in cold conditions, explants showed the highest number of microtuber induction. Also, the explants under 4 °C for 4 hours significantly increased the number of microtuber compared to the rest. According to results, cold treatment was more effective than heat stress in the tuberization percentage. The explants grown under 4 °C for 8 hours had the most tuberization percentage with 100%.

In general, stressors has a key role on microtuberization of potato compared to control condition. Among stress treatments, cold stresses have the most efficacy on in vitro microtuberization (number and fresh weight and dry weight of microtuber) and biomass of potato. In contrast, high temperature ameliorated tuberization degree, tuber diameter and also prevented microtuber growth. Altogether, 4°C for 8 hours as the best treatment can be recommend for industrial purpose.

Lettuce (Lactuca sativa L.) is one of the most important leafy vegetable. Due to importance and high demand the greenhouse and hydroponically growing of lettuce is increasing. One of the key points in effectiveness of hydroponic production is the formulation of suitable nutrient solution. Nitrogen as an essential element could be provided by two form in nutrient solution, ammonium and nitrate. Although both form provide the nitrogen for plants but they can affect the growth and physiological aspects differentiatly. In other side open systems of hydroponic in addition to to high cost for nutrient solution preparation can cause soil and water pollution, so its need to use hydroponic systems that decrease the amount of nutrient solution consumation. In this study we assessed the effect of three different NH4+:NO3- ratio in nutrient solution in an easy and very low cost closed hydroponic system so called Kratky method on lettuce production.

The experiment was conducted in hydroponic greenhouse as a factorial based on completely randomized design. Three nutrient solutions with the same level of total nitrogen but with different ammonium to nitrate ratio (0.5:8, 1:8 and 2:8) were used for growing the three lettuce cultivars (Local Romain, French red and Salinas) in closed hydroponic system without the exchange of nutrient solution during the growing cycle and just water were added to substition the of the consumed solution. The seeds of lettuce cultivars at first were planted in cell try that were filled with coco peat-perlite with 1:1 ratio and after emergence and until reaching to suitable size for transplating seedling were fertigated with hoglnd nutrient solution. Two lettuce seedlings were transplanted via the small plastic small baskets and styrofom plate in pots with seven liters volum until the end of growing period. The characters like leaf and root fresh and dry weight, chlorophyll, carotenoid and anthocyanin content were assessed.

The results indicate that the ammonium:nitrate ratio had significant effect on the lettuce leaf and roots fresh and dry weight, chlorophyll index and anthocyanin contents. The cultivars had significantly difference effects on leaf and roots fresh and dry weight, collorophyl index, carotenoid and anthocyanin content. But the interaction between the ammonium:nitrate ratio and lettuce cultivars were not significant on the investigated characters. Between the cultivars Salinas and locally Romaine respectively had the highest and lowest yield. The highest and lowest root fresh and dry weights also were obtained from the 2:8 and 0.5:8 ammonium to nitrate ratios respectively while the 0.5:8 and 1:8 ammonium to nitrate ratio were not the significantly different from each other on the leaf fresh wight. The same rule also was for the leaf dry weight. The Salinas and French red had the highest dry weight and the localy romain significantly leaf lowest dry weight. On the roots fresh and dry weight characters there was significantly difference between the cultivars that was close to the results on leaf fresh and dry weight. So that Salinas withought the significantly difference with the French red had the highest root fresh weight and lowest root fresh weight belongs to locally romain. Result showed that lettuce being a vegetative crop satisfied by increasing the ammonium:nitrate ratio in nutrient solution. This is close to the results that previously has been reported by some authors.

The highest fresh and dry weights of lettuce were obtained by the solution with the 2:8 ammoniums:nitrate ratio, which indicate the superiority of the lettuce simultaneously feeding with nitrate and ammonium. In addition to quatitative characteristic like the yield the yield, simoultaneously feeding with ammonium and nitrate affected the qualitative characteristics like the anthocyanin and cartenoeid contents. Also providing the some parts of Nitrogen needs of plant as ammonium can reduce the nitrate accumulation. All of three nutrient solution with different ammonium to nitrate ratio but with the same level of total nitrogene and without any need to aeration also without the change of nutrient solution and only by substitution of consumed water were able to feed the lettuce plants without any visible disorders. This kind of hydroponic due to the drastic decrease of production costs would be suitable method specially for small scale hydroponic vegtable production greenhouse.

In recent decades, agriculture based on the use of biological fertilizers has been considered with the aim of eliminating or significantly reducing the consumption of chemical inputs. In sustainable agricultural systems, the use of biological fertilizers is of particular importance in increasing the quality yield. It has a small yield and maintaining the stable fertility of the soil. Biofertilizers make the plant have a favorable access to water and nutrients and ultimately increase the yield of the plant.Considering the importance of the potato product in nutrition and the importance of producing and cultivating disease-free seed tubers, and on the other hand, the concerns raised in terms of the use of chemical fertilizers in the production of this strategic product, the present study is in line with The effect of biofertilizers on agronomic, physiological traits and yield of mini tuber potato seedlings of Jelly and Agria cultivars in Ardabil province was planned. So that by using the results of this research, an effective step can be taken in reducing the use of chemical fertilizers and increasing the production of healthy mini-tubers.

A greenhouse test was conducted as a completely randomized factorial design with three replications and three treatments including three species of growth-promoting bacteria (Pseudomonas p169, Pseudomonas p168, and Azotobacter 106) at three levels (0.05, 0.1, and 0.2 liters), and Jelly and Agria cultivars in ZarGostarArta Greenhouse to study the effect of using growth-promoting bacteria and mycorrhizal fungi on morpho-physiological characteristics and tuber yield of the obtained plantlets from potato tissue culture of Jelly and Agria cultivars. After applying the treatments, the tuber of plantlets was planted in the vase and kept for 3 monthsIn order to measure the total dissolved solids in the mini-tube, the cheap and efficient Saba method was used.Finally, the obtained data were analyzed using SAS 9.1 statistical software, comparison of means was done using LSD test at 5% probability level and simple correlation of traits.

The obtained results from this research showed that the simple, two-way, and three-way effects of treatments (growth-promoting bacteriaand cultivar) were significant in a 1% p-value on all the morpho-physiological characteristics. The growth and yield and dry matter of many crops such as potato, corn and wheat using growth promoting bacteria have been reported all over the world. Researchers reported that photohormonal changes due to the use of growth promoting bacteria caused an increase in length. Root and root dry weight. The results show that the use of growth stimulating bacteria showed better results. So that the highest number of leaves in the plant was related to the treatment of 0.2 liters of Pseudomonas p169 bacteria of the Agria variety, in other words, the combination of Agria in the treatment of growthstimulating bacteria with 0.2 liters of Pseudomonas p169 with an average of 42.5 and the combination Jelly cultivar had the least number of leaves in the control with 15 leaves. The researchers reported that the bacterial and fungal treatments led to a significant increase in the number of leaves per plant These results confirm the existence of a synergistic relationship between rhizospheric bacteria that stimulate plant growth and show that this beneficial cooperation between these microorganisms improves plant growth and the amount of product production per unit area. In treatments inoculated with biofertilizers, the increase in the dry weight of the plant can be due to the increase in the absorption of nutrients such as nitrogen, phosphorus and potassium as a result of root expansion. The comparison of the average effect of simple bacteria on potato plant phosphorus is shown in figure 1, the control treatment had the highest amount of phosphorus with an average of 47.05 and the treatment using 0.1 liter of Pseudomonas p169 with an average of 44.55 had the lowest amount of phosphorus appropriated the comparison table of average elements showed that the highest amount of nitrogen (14.23 mg/g dry weight) was obtained from the Agria cultivar with the use of 0.2 liters of Aztobacter 106 bacteria. Also, the results of comparing the average potassium element showed an increase of this element with the use of 0.1 liter of Azotobacter 106 bacteria in Jelly variety and the use of Az-0.2 in Jelly variety. The average comparison of zinc element also showed that the highest amount (0.043mg/g dry weight) was obtained from Agria variety and 0.1 liter of Pseudomonas p168. The highest amount of iron (0.33 mg/g dry weight) was obtained from the application of 0.2 liters of Pseudomonas p169 in Agria variety.

The result of this research showed the increasing effect of biological fertilizers on the morpho-physiological traits of potato. Biofertilizers improved the measuring characteristics and qualitative characteristics of potato, and the highest amount of investigated traits for most of the traits was observed in the combination of 0.1 and 0.2 liters of Pseudomonas bacteria.

Satureja khuzistanica is a native plant of Iran, which is used as a vegetable, spice, decoction, painkiller and disinfectant in traditional medicine, food and pharmaceutical industries, and has antifungal, antimicrobial and antibacterial properties. It is pain-relieving, anti-diabetic, antioxidant, anti-inflammatory, reduces blood fat and triglycerides. One of the problems of mass production of plants through seeds and seed production industries is the low germination percentage of wild plant seeds due to the lack of ecological compatibility with domestic environment conditions. The quality of light is one of the most important environmental factors for the growth and development of plants, so the use of different light spectrums is one of the stimulating methods to increase the indicators of seed germination of different plants and their seedling growth.

In order to investigate the effects of light quality on the germination indices and biochemical characteristics of S. khuzistanica, an experiment was conducted in the form of a completely randomized design in three replications in 2022, in the Medicinal Plants and Drugs Research Institute of Shahid Beheshti University, Tehran. The experimental treatments included the combination of light at four levels (red light, 30% blue + 70% red, blue, fluorescent). S. khuzistanica seeds were obtained from the collection of medicinal plants of Shahid Beheshti University's Medicinal Plants and Drugs Research Institute and were washed for 30 seconds with a five percent sodium hypochlorite solution and then washed four times with sterile distilled water and 40 seeds were selected in each petri dish and in four Rows are arranged randomly. Germination indices (germination percentage and speed), growth indices (shoot and root length, shoot and root dry weight) and biochemical characteristics (chlorophyll a, chlorophyll b, carotenoid, total phenol, peroxidase, and super oxidase dismutase and catalase enzyme activity) were evaluated.

The highest percentage of germination (84.33%) and germination speed (45.87%) were achieved with the use of red light. Also, the highest length of radicle (3.53 cm), the highest dry weight of radicle (0.51 mg/seedling) and the dry weight of plumule (0.45 mg/seedling) in the treatment of 30% blue + 70% red and the highest length of plumule (1.68 cm) were obtained in the red treatment, respectively. The highest chlorophyll a (0.58 mg.g-1 FW) and chlorophyll b (0.49 mg.g-1 FW) were observed in red light treatment and the highest carotenoid content (0.48 mg.g-1 FW) was observed in blue light treatment. With the use of blue light, the activity of catalase and peroxidase enzymes increased and the activity of superoxide dismutase decreased.

The results of this research showed that the germination indices, growth and biochemical characteristics of S. khuzistanica seedlings were affected by different light spectrums. In general, the results indicated the possibility of improving the germination indices, growth and biochemical characteristics of S. khuzistanica seedlings using a combination of blue and red lights compared to fluorescent light.

In higher plants, chromium (Cr) is not essential to plant growth and function. Exposure to Cr may cause tissue necrosis and limit chlorophyll production. In particular, Cr is usually involved in electron transfer and induce production of reactive oxygen species (ROS) (e.g., hydroxyl radicals and superoxide radicals), resulting in oxidative stresses and damages to plant cells and tissues. Humic acid (HA) and fulvic acid (FA) are the major component of humic substances. FA has low molecular weight and contains more oxygen-rich and carbon-poor functional groups compared with HA. It has been reported that soil and foliar applied FA increased the intensification of seedling growth, seed germination energy, and root weight of wheat plants. However, the aim of this research was to investigate the effect of different chromium concentrations on growth and biochemical parameters and stress indices in lettuce fed with fulvic acid, as a stress modifier in hydroponic system.

In order to investigate effects of fulvic acid application on morphological and physiological and biochemical under chromium stress in red leaf lettuce (Lactuca sativa L.), a pot experiment was conducted as factorial based on completely randomized design with four replications under hydroponic culture in university of Mohaghegh Ardabili in 2021. Experimental treatments were consisted of chromium stress at three levels (0, 3 and 15 mg l-1) and fulvic acid application at two levels (0 and 50 mg l-1). In this research, morphological traits including, shoot and root fresh weight, root length, root to shoot ratio and physiological traits such as total chlorophyll and carotenoid, leaf chromium content, soluble protein, malondialdehyde, relative water content, catalase, hydrogen peroxide were evaluated. 

The results revealed that Application of fulvic acid in plants grown under chromium stress caused an increase in root length and soluble protein compared to plants grown under chromium stress alone. While the addition of fulvic acid to the nutrient solution in chromium stressed plants showed a significant decrease in leaf chromium content, membrane peroxidation and hydrogen peroxide compared with the plants grown under Cr stress. The application of chromium at a concentration of 15 mg L-1compared to the control treatment reduced the root and shoot fresh weight, total chlorophyll and carotenoid and catalase by 20.5, 21.7, 22.3, 19.5 and 26%, respectively. Plants fed with 50 mg L-1 fulvic acid compared to the control treatment, root and shoot fresh weight, root to shoot ratio, total chlorophyll and carotenoid water relative content increased by 16.5, 15.5, 103 and 37%, respectively.

The addition of fulvic acid improved morphology and physiological traits, and abiotic stress indicators in lettuce under Cr stress. Result showed that the alleviation of Cr toxicity might be associated with decreased Cr uptake in roots leading to reduced Cr translocation in the shoot. Further, fulvic acid addition decreased membrane stability and hydrogen peroxide in response to Cr stress.

Drought stress can limit the growth and yield of plants like peppermint. One way to increase yield and product quality is by using growth stimulants that can increase resistance to stress and accelerate plant development. The role of growth stimulants is to increase resistance to stress and accelerate plant development and growth, especially of roots and leaves. Kitoplus is a growth stimulant that contains chitosan and has been used to reduce the effects of drought stress. Iron also reduces the effects of drought stress by improving gas exchange, stomatal conductance, water use efficiency, and reducing transpiration. The use of nano-fertilizers for plant nutrition is a new application of nanotechnology in agriculture. Iron oxide nanoparticles with chitosan coating can provide the necessary elements for plants. This study examined the effect of chitosan-coated iron oxide nanoparticles on mitigating drought stress in peppermint.

To assess the impact of Kitoplus growth stimulant and chitosan-coated iron oxide nanoparticles on peppermint yield, morphology, and essential oil under drought stress, a factorial split-plot experiment was conducted. The experiment had three replications and treatments included three levels of water stress (irrigation in soil moisture depletion of 30, 60, and 90% of field capacity moisture), three concentrations of Kitoplus growth stimulant (0, 0.5, and 1%), and three concentrations of chitosan-coated iron oxide nanoparticles (0, 5 and 10 µM)). Peppermint rhizomes planted in small pots and keeping them in a greenhouse for 20 days before planting in the experimental field. Drought stress and foliar spraying began 20 days after transferring the plants to the field. Soil moisture was measured using hygrometer sensors and irrigation was done when the desired level of soil moisture was reached (90, 60 and 30% soil FC moisture) with an equal volume (400 liters) for each plot separately. Foliar application was performed three times with a 15-day interval. One week after the last spraying, characteristics such as stem diameter, number of nodes, inter-node distance, flower cluster weight, fresh and dry weight of aerial parts, and essential oil percentage were evaluated.

The study found that foliar spraying with Kitoplus growth stimulant and chitosan-coated iron oxide nanoparticles had a positive impact on peppermint yield and quality, especially under drought stress. Drought stress significantly affected the fresh and dry weight and morphology of peppermint. Increasing irrigation, Kitoplus growth stimulant concentration, and chitosan-coated iron oxide nanoparticle concentration improved these attributes. However, high concentrations of Kitoplus growth stimulant and chitosan-coated iron oxide nanoparticles caused a sharp decrease. The ratio of dry to fresh weight was higher in treated plants than in untreated plants under irrigation conditions. The highest ratio of dry to fresh weight (36.08%) was observed in plants treated with 1% Kitoplus growth stimulant and 5 µM chitosan-coated iron oxide nanoparticles under 30% field capacity irrigation conditions. The highest essential oil yield was observed in plants under 90% field capacity irrigation conditions combined with 1% Kitoplus growth stimulant foliar application (1.056 ml per 30 gr of dry tissue).

The study concluded that combined foliar application of 0.5% Kitoplus growth stimulant and 10 μM chitosan-coated iron oxide nanoparticles had a greater impact on peppermint yield and quality, especially under drought stress. This treatment compensated for the negative effects of drought stress. In general, agricultural techniques can increase peppermint yield and essential oil percentage.

Plants survive in salinity stress by different mechanisms (Mustafa et al., 2020). Melon is grown in arid and semi-arid regions worldwide especially in where the salinity is a threat. Iran is known as one of major centers of diversity for melon in the world (Pitrat, 2008). There is a wide genetic variation among Iranian native melon landraces. This wide range of diversity can be exploited for increasing drought tolerance in breeding programs. Iran ranks fifth in global melon production (FAOSTAT, 2019). Cultivation of native melons in Iran is offten implemented in the margins of desert areas which have degrees of drought and salinity. Therefore salinity tolerance is known as important factor in melon cropping in Iran. Melon is known as a semi-salt-tolerant plant. Salinity stress causes numerous damages such as irregular growth and developement, metabolic disorders, yield loss and poor flesh quality of Melon. Tolerance of melon genotypes to salinity stress depends on the genetic tolerance of genotypes, environmental factoers like of salinity, and plant growth stage. The most marketable Iranian Melon genotypes are produced in warm and dry weather. According to the classification, Iranian Melon, is one of the plants adapted for semi-saline area (Sobhani & Hamidi, 2014).

This study was carried out in 2019 cropping season in Vegetable Research Center (VRC) of Horticulture Science Research Institute of Iran (HSRI) in factorial were administered in three replications design based on completely randomized block design with six melon genotypes including Durango, Shadegani, Shahabadi, Dargzi, Atashi and Khatouni and five salinity levels including 0, 30, 60, 90 and 120 mmol Sodium Chloride. Melon genotypes was planted in the sand in the greenhouse. The sand was washed three times with tap water and sterilized in 120 °C and 1 bar for 30 minutes. Seeds were sown in about 10 L of sterilized sand in plastic pots. Wet weight of oots and shoots were measured and then placed in the oven at 70 °C for 48 hours to measure the dry weight. Genotypes tolerance to salinity was evaluated by the Van-Hoffman index (Mangal & Hooda, 1988). Germination percentage and relative growth in traits in both wet and dry plant organs were analyzed in factorial statistical method using SAS 9.4. Comparing means of the traits were laied out with Duncan’s Multiple Range Test. All graphs were drawn using Excel 2013 software.

In 30 mmol of salinity, Dorango, Shadegani, Shahabadi, Dargzi, Atashi and Khatouni genotypes, respectively, and in 60, 90 and 120 mmol salinity Dorango, Shahabadi, Shadegani, Dargzi, Atashi and Khatuni genotypes, have the highest germination percentage respectively. Compared to the control (No salinity). Studying salinity tolerance of studied genotypes in vegetative growth stage showed that in 30 mmol salinity Shadegani, Dorango, Shahabadi, Khatouni, Atashi, Dargzi genotypes, respectively, in 60 mmol salinity Shadegani, Durango, Shahabadi, Khatouni, Dargazi genotypes, respectively. Atashi, at 90 mmol salinity, Shadegani, Durango, Khatouni, Dargzi, Shahabadi, Atashi genotypes, respectively, and at 120 mmol salinity, Shadegani, Durango, Shahabadi, Khatouni, Dargzi, and Atashi genotyopes, respectively. Germination was significantly different in the studied genotypes and decreased with increasing salinity level.

This result confirms the results of the similar researchs. Therefore, it is suggested that the salinity level and the proper genotype for that salinity level must be determined for a high yielding marketable fruit production.