j. nabati

Chickpea (Cicer arietinum L.) is one of the most important crops in the human food basket worldwide. It is a highly nutritious pulse crop with low digestible carbohydrates, protein, essential fats, fiber, and a range of minerals and vitamins. As the human population grows, the demand for this protein source increases and various approaches to its sustainable products are being developed. Autumn cultivation of chickpea in cold regions requires the introduction of cultivars tolerant to freezing stress. The ability of plants to overwinter depends on the biochemical and physiological responses induced by their cold acclimation duration. Cold acclimation mechanisms in the plant are a fundamental reason for plant tolerance increase in autumn cultivation. Hence, investigating the mentioned traits can help identify cold-tolerant genotypes. Identifying attributes that provide a suitable description of the diversity between genotypes is critical through canonical correlation analysis, cluster analysis, and determining the genetic distance.

This experiment was conducted during the 2017-18 growing season in the research field of Ferdowsi University of Mashhad, Iran (Lat 36° 15′ N, Long 59° 28 E; 985 m Altitude). Chickpea germplasm, including 29 Desi-type chickpea genotypes and one cold tolerant cultivar (cv. Saral), was studied in terms of morpho-physiological and biochemical attributes and their relationship with yield and yield components. Chickpea seeds were provided from the Mashhad chickpea collection at the Research Center for Plant Science. Following seedbed preparation by ridge tillage in October 2017, chickpea seeds were sown with a density of 40 plant m-2. Irrigation was conducted three times during the growth period: immediately after sowing, two weeks after the first irrigation and flowering stage. Hand-weeding was done three times during the growth stage in early March, early April, and early May. Data were analyzed using the SAS 9.4 software, and the mean comparison was performed by the Duncan Multiple Range Test (DMRT) at a 5% probability level. Statistica software also performed a cluster analysis (based on Euclidean distance) and principal component analysis (PCA).

Evaluating the morpho-physiological performance of chickpea genotypes is valuable for breeding programs that integrate chickpea cold tolerance. Based on Pearson's correlation coefficient results, a significant positive correlation was observed between the survival of chickpea germplasm with seed yield and biological yield. Also, a significant negative correlation between survival with photosynthesis pigment content and Fv'/Fm' revealed a high relationship between these parameters. Traits with the highest canonical discriminate coefficients had the best effect on the diversity across the studied genotypes. Based on the factor analysis results, the first factor with 22.8%, and the second with 12.1% explained the most differences. In the first factor, the most critical traits with a positive charge are Fv'/Fm', the total content of photosynthetic pigments, starch, the number of fertile pods, and the number of seeds, and the critical trait with a negative charge was the survival. The genotypes of the five cluster analysis groups had a higher mean in 54% of the traits compared to the total mean. The crossing of genotypes of group one due to higher survival and seed yield and genotypes of group five due to plant height and first pod height (compared to the total mean), which also have a considerable genetic distance, can lead to the release of new varieties. Also, the genotypes of the three cluster analysis groups (MCC32, MCC34, MCC155, MCC194, MCC199, and MCC291) have high-priority traits for selection by breeders and can be used in breeding programs for autumn cultivation.

According to the results of the present study, selection for successful overwintering of desi-type chickpea genotypes in cold regions is recommended based on the mentioned characteristics in breeding programs. The group three chickpea genotypes of cluster analysis (MCC32, MCC34, MCC155, MCC194, MCC199, and MCC291) and morpho-physiological and biochemical attributes affecting the yield and yield components determined from this study may be helpful for genetic engineering and breeding programs that integrate chickpea cold tolerance.

The effect of salinity stress on the quantity and quality of crop production highlights the importance of managing and reducing the damage caused by this stress factor in agriculture. Increasing soil salinity and decreasing fertility of arable lands is one of the major problems in saline areas. Cultivation of salt-tolerant crops which can increase soil fertility could be effective in the sustainable production of these lands. Studying photosynthesis and its related factors could provide appropriate physiological views in understanding plant behavior against salinity stress. The present study was conducted to assess the salinity tolerance of chickpea genotypes for cultivation in saline areas.

To evaluate the effects of salinity stress on photosynthetic criteria and yield of chickpeas, an experiment was conducted in 2018 at the research farm of the faculty of agriculture, Ferdowsi University of Mashhad, Mashhad, Iran. The experiment was arranged as a split plot based on a randomized complete block design with three replications. Experimental factors consisted of salinity levels (0.5 and 8 dS.m-1) as the main plot and chickpea genotype (17 kabuli-type genotypes) as the subplot. Seeds were provided from the Mashhad chickpea collection of the Center for Plant Sciences, Ferdowsi University of Mashhad, Mashhad, Iran. Seeds were planted on March 11th and complementary irrigation was done in three growth stages of pre-flowering, flowering, and pod-filling. Sodium chloride was used to prepare saline solutions and the irrigation water rate was measured by water meter. Photosynthetic criteria including photosynthesis rate, evapotranspiration, stomatal conductance, and resistance and concentration of photosynthetic pigments were measured in the 50% flowering stage.

Results indicated that the lowest and highest reduction in the concentration of chlorophyll a was found in MCC65 (6%) and MCC83 (3.3 times increase), respectively. Increasing salinity level increased the concentration of chlorophyll b in MCC65 and MCC139, the ratio of chlorophyll a/b in MCC92, MCC139, and MCC776, carotenoids concentration in MCC77, MCC92, MCC313, and MCC679 and total pigments in MCCMCC77, MCC92, MCC298, and MCC679. Increasing salinity levels led to higher evapotranspiration in 14 genotypes except for MCC65, MCC95, and MCC298 in which 37, 54, and 63% decrease of this parameter was observed. Increasing salinity level increased photosynthesis rate in 7 genotypes of MCC12, MCC65, MCC72, MCC92, MCC95, MCC679 and MCC776 among which MCC95 and MCC679 showed the highest percentage increase (61 and 53%, respectively). The highest increase in sub-stomatal CO2 (51, 49, and 40 ppm) with increasing salinity levels, was found in MCC485, MCC776, and MCC313, respectively. An increase of 28 and 8% in stomatal conductance was found in MCC65 and MCC95. Stomatal resistance was only reduced in MCC77, MCC420, and MCC29. Higher salinity levels also led to 3.4 times, 67, 14, and 13% increase in instantaneous water use efficiency in MCC95, MCC65, MCC92, and MCC298, respectively. Biomass and seed yield declined in all genotypes by salinity. The highest seed yield was observed in MCC65, MCC77, MCC92, and MCC95 with 142, 148, 167, and 166 g.m-2 respectively in saline conditions. There was a negative significant correlation between seed yield and evapotranspiration (r=-0.43**), and stomatal resistance (r=-0.38**), and a significant positive correlation between seed yield and biomass (r=0.61**) and photosynthesis (r=0.24**) and stomatal conductance (0.36**).

In general, the results of this experiment indicated the diversity among chickpea genotypes for salinity tolerance caused by saline irrigation water. Studying some photosynthetic criteria in 17 kabuli-type chickpea genotypes under salinity stress showed high diversity in physiological responses of chickpeas to salinity stress which could be used in the selection and breeding of salt-tolerant cultivars. MCC65, MCC77, MCC92, and MCC95 were superior in most studied criteria in saline conditions and even performed, unlike the declining trend of the other genotypes. It seems that these genotypes could produce reasonable seed yield in salinity levels up to 8dS.m-1.

Cross-acclimation of mild drought stress and cold acclimation may additionally increase the chickpea’s cold tolerance due to transferring sowing date from spring to winter in Mediterranean high lands. Two weeks after sowing in greenhouse, chickpea seedlings were subjected to the following treatments in a controlled environment: (i) Well-Watered under an optimum temperature regime (WW); (ii) Well-Watered under a Cold temperature regime (WWC); (iii) Drought Preconditioned under an optimum temperature regime (DP); and (iv) Drought Preconditioned under a Cold temperature regime (DPC). After three-week acclimation period, plants were frozen on the thermogradient freezer, then, recovered for three weeks in a greenhouse. In the acclimation period, with decreasing temperatures, a clear decrease of the electrolyte leakage (EL) were observed for both genotypes: 51% for cold tolerant MCC252 and 36% for cold sensitive MCC505. Cold acclimation induced the greatest accumulation of proline and MDA contents (about 75% for both genotypes) and drought preconditioning most consistently induced an increase in soluble carbohydrate content (25% for MCC252 and 51.7% for MCC505) during the acclimation period. The survival percentage increased 9.3% for MCC252 and 21.25% for MCC505 by both cold and drought acclimation under freezing conditions. Generally, drought preconditioning had a synergistic effect on the cold acclimation period to improve freezing tolerance (as indicated by the lowest LT50el and LT50su) and leading to an increase in the freezing tolerance for the cold sensitive genotypes (MCC505). Thus, the greatest gains in freezing tolerance for both genotypes were associated with cross-acclimation treatment (DPC).

Due to climate change, one of the limiting factors of crop production is environmental stress which, by disrupting the natural metabolism of the plant, limit plant growth and finally reduce crop production. Drought stress causes the greatest reduction in crop productivity compared to other environmental stresses. Therefore, the use of methods to reduce water consumption in agriculture is more important due to the lack of freshwater resources. Increasing water use efficiency and maintaining plant yield by reducing water consumption has a particular importance for crop production and should be paid special attention. Drought stress reduces photosynthesis, stomatal conductance, biomass, growth and consequently plant yield. The effects of drought stress on the yield of plants such as potatoes (Solanum tuberosum L.), wheat (Triticum aestivum L.), rice (Oryza sativa L.) etc., which play an important role in the nutrition and food of the world, has a great importance. Achieving the desired soil moisture range is one of the most important approaches to increase water use efficiency and not significantly reduce yield. For this goal, a factorial experiment was conducted in a completely randomized design with five replications in the research greenhouse of Ferdowsi University of Mashhad.

Factors studied in this experiment included three levels of irrigation 1- full irrigation (100% of field capacity), 2- medium drought stress (70% of field capacity), 3- partial root-zone drying (70% of field capacity), time of induction of water stress (two weeks after planting and 50% at flowering time) and two levels of phosphate (CaH4[Po4]2 H2O) fertilizer (based on soil analysis (25 mg.kg-1) and adding 25% more than recommended (31 mg.kg-1)) at the beginning of the period phosphate was mixed with soil inside the pot in greenhouse condition. Fontane potato cultivar was used in this study. In irrigation treatments, one part of the pots was stressed two weeks after planting and the second part of the pots were fully irrigated until the beginning of flowering and irrigation treatments were applied at 50% flowering stage. From the prepared samples, membrane stability index, osmotic potential, and relative water content were measured in the laboratory and at the end of experiment, plant height, tuber weight, biomass and plant water use efficiency were measured. Minitab 18 software was used to analyze the data.

The results showed that with increasing phosphate fertilizer from 25 mg.kg-1 to 31 mg.kg-1, plant biomass increased significantly and in all treatments biomass increased between 2 to 28% . Partial root-zone drying treatment showed a 17.4% increase in biomass. In the medium drought stress treatment, the total growth period and phosphorus level of 31 mg.kg-1, the lowest water use efficiency was observed, and there was no significant difference in the medium drought stress treatment of the total growth period and the phosphorus level of 25 mg.kg-1. Partial root-zone drying treatment of roots from flowering time and 31 mg.kg-1 P, with full irrigation treatment 25 mg.kg-1 P have the same water use efficiency, but the performance of this treatment  compared to full irrigation treatment was reduced by 28%. Water use efficiency in partial root-zone drying (intermittent irrigation) has increased compared to traditional irrigation, which indicates a more optimum use of water in the medium drought stress method. Full irrigation treatment had the highest tuber weight per plant and partial root-zone drying during the growing season treatment had the lowest tuber weight per plant (65%) compared to full irrigation. The partial root-zone drying treatment after flowering, ranked second after full irrigation treatment, for tuber weight per plant and more tuber weight per plant compared to other drought treatments. Using 31 mg.kg-1 phosphate, tuber weight per plant in full irrigation treatment reached 332 g.plant-1 which increased by 13% and was significantly different from all treatments. With increasing phosphate level from 25 mg.kg-1 to 31 mg.kg-1, in the partial root-zone drying treatment from flowering time, tuber weight per plant increased by 28% to 207 g.plant-1. Tuber weight per plant in other drought treatments decreased with increasing phosphate level from 25 mg.kg-1 to 31 mg.kg-1, although this decrease was not statistically significant.

Compared to deficit irrigated methods, partial root-zone drying from the beginning of growth and full irrigation has the ability to use available nitrogen at the end of the growing season and has more greenery than other drought treatments. This effect probably explains the filling of the gland tubers at the end of the growing season and thus the keeping of yieldyield production. The best methods for saving water consumption and maintaining the yield, the partial root-zone drying methods is better than the medium drought stress method.

Salinity tolerant of 24 lentil genotypes was investigated in a split-plot based on a randomized complete blocks design with three replications. Salinity levels (0.5, 12, and 16 dS m-1) were arranged as the main plot and lentil genotypes as the subplot. Results indicated that salinity levels of 12 and 16 dS m-1 reduced the survival percentage of all genotypes compared to control. MLC57, MLC73, MLC94, MLC104, and MLC108 genotypes were not able to tolerate the 16 dS m-1 salinity level. Morphological traits were affected by salinity stress as plant height, number of branches per plant, dry weight, and leaf survival percentage in most genotypes were decreased. Compared to control, the lowest reductions of plant height, number of branches per plant, plant dry weight, and leaf survival percentage were observed at salinity level of 16 dS m-1 in MLC13, MLC120, MLC4, and MLC12 genotypes, respectively. Also the lowest increase in Na+ (5.5 times) and the highest increase in Ca2+ (4 times) were observed at salinity level of 16 dS m-1, in MLC108 and MLC78, respectively. In other words, these genotypes were able to reduce the adverse effects of increased NaCl in higher salinity levels. Principal component analysis (PCA) showed that all genotypes of the first group (MLC6, MLC12, MLC26, MLC117, MLC120, and MLC178) were superior for most traits as compared to the total mean. Generally, it could be concluded that this group of genotypes has a better survival percentage and growth characteristics in salinity conditions, which may be used to select salinity tolerant lentil genotypes in subsequent studies.

The excessive use of chemical fertilizers devastates soil fertility and causes different types of environmental pollution. Therefore, using adequate eco-friendly fertilizers in agriculture enhances productivity but has no adverse effect on nature. Recently, there has been reported that beneficial soil microbes produce some volatile organic compounds, which are beneficial to plants. The amendment of these microbes with locally available organic materials and nanoparticles is currently used to formulate biofertilizers for increasing plant productivity. These bacteria are naturally present in soils, but their population decreases for a long time because of long-term environmental stress, improper use of chemical agents, and the absence of a suitable host plant. Adding these bacteria to the soil, before or during the growing season, increases the growth and production of agricultural products. Since available water is the main growth limiting factor in chickpea cultivation, it is useful to improve nutrition, especially using plant growth-promoting rhizobacteria, for accelerating the growth and development of plants at the end of the season.
In order to evaluate the effect of bio-nutrition and seed priming on growth and yield of chickpea genotypes (MCC463, MCC741, ILC8617, ILC72, FLIP02-51C) an experiment was carried in split plots based on Randomized Complete Block Design with three replications in 2019. Experimental factors included nutritional treatments as the main plots and chickpea genotypes as the subplots. Nutritional treatments were 1- seed priming with the use of free-living nitrogen fixing bacteria, phosphorus solubilizing bacteria and potassium solubilizing bacteria (P + BF), 2- free-living nitrogen fixing bacteria, phosphorus solubilizing bacteria and potassium solubilizing bacteria before sowing (BF), 3- seed priming with the application of free-living nitrogen fixing bacteria, phosphorus solubilizing bacteria and potassium solubilizing bacteria with foliar application of amino acid, potassium and silicon during growth stages (P + BF + F), 4- application of free-living nitrogen fixing bacteria, phosphorus solubilizing bacteria and potassium solubilizing bacteria before planting with foliar application of amino acid, potassium and silicon during growth stages (BF + F), and 5- control (without biological and chemical fertilizers). Free-living nitrogen fixing bacteria, phosphorus solubilizing bacteria and potassium solubilizing bacteria were sprayed five liters per hectare on the soil surface before planting with 107 CFU per ml and mixed with soil. Foliar application with amino acid (1:1000) was done in two stages (before flowering and 50% flowering stage), and foliar application with potassium (1:1000) and silicon (1.5:1000) was carried out in the 50% flowering stage.
Results showed that the highest concentration of chlorophyll a was obtained for BF and MCC463 with an increase of 3.1 times greater than control. The highest concentration of chlorophyll b was obtained for BF + F and FLIP02-51. The highest green area index was recorded for MCC741 in P + BF. The highest number of pods per plant in MCC463 and FLIP02-51 was observed in BF + F, with 88 and 30% more than the control, respectively. The highest biomass produced was obtained for ILC8617 and BF + F, by 24% higher than the control. ILC72 and MCC463 showed the highest grain yield in P + BF + F treatment, which increased grain yield by 35% and 4% (320 and 50 kg/ha), respectively, with respect to control. MCC741under BF treatment showed a doubled (810 kg/ha) grain yield relative to control. The highest grain yield for P + BF was found in ILC8617 and increased by 28% (340 kg/ha) as compared to control. In this genotype, grain yield in BF + F was also significantly greater than that in the control by 22%, (270 kg/ha). FLIP02-51 grain yield in BF increased by 12% (170 kg/ha) as compared with the control.
In terms of seed yield, ILC72 and MCC463 were more responsive to P + BF + F and ILC8617 and FLIP02-51 in the BF and ILC8617 in P + BF with respect to other treatments. It seems that despite the positive effect of biofertilizer, genetic characteristics of genotypes are influential in plant growth and yield; therefore, it is necessary to select the appropriate genotype for each region so as to make the most utilization of the nutrients and achieve high yield.

To study freezing tolerance (-13, -15 and -18°C) of 40 lentil (Lens culinaris Medik.) genotypes, a factorial experiment in completely randomized design was carried out at the Research Center of Plant Science, Ferdowsi University of Mashhad, Mashhad, Iran, in 2017-2018. Significant differences observed between genotypes for survival percentage after freezing stress and chlorophyll a, carotenoids, anthocyanins, soluble carbohydrates, proline, malondialdehyde (MDA), phenol, protein, DPPH, ascorbate peroxidase and peroxidase before freezing stress. Stepwise regression analysis showed that chlorophyll b had the most positive effect and protein, and MDA had the most negative effect on survival percentage. Cluster analysis grouped genotypes into five clusters. For most of the studied traits, genotypes in clusters 4 and 5 were greater than average of all genotypes as well as genotypes in other clusters. In clusters 4, anthocyanins, protein, MDA, phenol, proline, ascorbate peroxidase and peroxidase contents were higher than other clusters. Survival percentage, chlorophyll b, carotenoids, total pigments, and DPPH of cluster 5 were higher than the other clusters. Principal component analysis showed that MLC469, MLC458, MLC409, MLC74, MLC84, MLC169, MLC394, MLC95, MLC17, MLC163 and MLC303 for antioxidant capacity and metabolites, and MLC70, MLC410, MLC47, MLC31, MLC91, MLC8, MLC286, MLC407, MLC472, MLC61, MLC83 and MLC334 for photosynthetic pigment capacity were more suitable than the other genotypes. It can be concluded that these attributes are very important in predicting, before cold stress, the effect of cold stress on survival percentage of lentil genotypes.

To study freezing tolerance of 40 genotypes of lentil (Lens culinaris Medik.) an experiment as factorial arrangements in completely randomized design with three replications was carried out at the research center for plant science, Ferdowsi University of Mashhad, Mashhad, Iran, in 2017-2018. Genotypes were exposed to three levels of freezing temperatures (-13, -15 and -18 °C). The results showed that at -13, -15 and -18 °C temperature levels, 100, 93 and 30 percent of genotypes had no significant difference with their maximum survival (100%), respectively. Only three genotypes MLC12, MLC17 and MLC95 were able to maintain 100% survival at all three freezing temperature levels. The lowest temperatures reducing 50% of leaf area (RLAT50) and dry matter (RDMT50) were -16.5 and -16.7 °C, respectively, and most of the genotypes succeeded in retaining 50 percentage of these traits during the recovery period. MLC8 and MLC286 genotypes with RDMT50 of -16.7 °C had the highest ability to maintain dry weight, whereas MLC74 genotype with RDMT50 of -13.4 °C had the least cold tolerance in respect to dry weight during recovery. Generally, 37 genotypes had reasonable level of tolerance to freezing stress. Therefore, based on the results of this experiment these 37 genotypes can be used in lentil breeding program for target areas with a minimum temperature of -15 °C.

Each year, with the onset of cold season and severe drop in temperature, the probability of frost bite and frost damage is a problem for landscaping plants. Many plant species, especially tropical and subtropical species, are damaged when exposed to frostbite, causing damage to their cells, tissues, and organs. Research has shown that by altering membrane properties during cold stress, metabolic balance is disturbed and with the increase in toxic metabolites, secondary damage to the plant can occur. At low temperature, decreases the efficiency of energy transfer to the center of the photosystem II. In addition, low temperatures are the main cause of the formation of reactive oxygen radicals. Also, lowering the temperature in the presence of light, due to the imbalance between light absorption and photosynthesis, increases the risk of light oxidation. Low temperature also reduces the activity of Rubisco. The amount of free proline in many plants increases significantly in response to environmental stresses such as frost stress, and stabilizes the membrane during cold stress.On the other hand, the use of some organic materials such as organic mulches increase temperature of the soil, and thus helps plant from frostbite. Use of organic mulch is widespread in agriculture due to the positive effect in soil temperature, weed control and moisture retention. Also, these mulches are effective in height, growth and flowering, early maturity and total yield of the products. Mulches in the warm seasons reduces soil temperature. Use of mulch can also help plants to withstand frostbite. Organic mulch decomposition in appropriate temperature and humidity conditions, liberates the nutrients gradually and provides for root plant and microorganisms of the soil. Organic mulches can reduce the effect of salt toxicity on plant growth and actively increase soil desalination. The most important benefit of mulch is the increase in soil temperature in the seed area, which accelerates the growth and yield of the product. Use of straw as mulch resulted in accelerated germination in cucumber. Use of straw mulch leads to an increase in temperature at night, thus protecting plants from temperature stress that has a positive effect on the growth and development of wheat.

In order to investigate the effect of freezing stress and using different types of organic mulch for Aquilegia plant, this experiment was conducted as a factorial experiment based on completely randomized design with four replications at Faculty of Agriculture, Ferdowsi University of Mashhad. The experimental treatments included four types of mulch (control (without mulch), 50% soil + 50% manure, 50% soil + 50% leaf needle + 50% soil + 50% rice bran) and five levels of freezing temperature (0, -5, -10, -15 and 20). Characteristics such as percentage of electrolyte leakage, relative water content, chlorophyll index and total chlorophyll, leaves number, leaf area, plant dry weight and proline leaf content were considered.

The results showed with decrease of temperature from 0 to -20 °C, stem diameter, leaf area and leaf number in bran mulch treatment decreased by 42.6%, 73.4%, 21.2% respectively, also stem diameter, leaf area and leaf number in mulch of leaf needle were 35.2%, 9/64%, 47.6%, in manure mulch were 20.20%, 46.4%, 7.8% and in the control of mulch decreased, 32.8%, 79.7%, 30.7%, respectively. At -5 °C, the amount of proline was 26% in the leaf and at -20°C, the amount of proline increased 50% compared to the control. Also, the lowest proline (0.73 μmol / g fresh weight) was obtained from the plants that treated with bran mulch. With application of, electrolyte leakage reached 63.6%, 68%, 61% and 57% in control conditions bran, needle and manure, respectively. In short, the least electrolyte leakage was observed in manure. On the other hand, when temperature dropped from 0 to -20 °C, the percentage of electrolyte leakage increased in Aquilegia. Relative water content of the leaf were 24% at 0°C, 38% at -15 °C and 23% at -20 °C. In terms of non-use of mulch, the relative water content was 36% and reached a 42% and 40% with application of manure and needle using mulch. By measuring the total carbohydrate found in Aquilegia leaf, it was observed that the amount of this trait was increased under frost stress. In general, although frost stress reduced the morphological traits of Aquilegia, use of organic mulch resulted in the improvement of these traits. The best results were observed in manure mulch.

  Low precipitation, high temperature and high evaporation along with excessive consumption of water sources have led to reduced quantity and quality of water sources (e.g. water salinization) in arid and semi-arid regions which ultimately affect crop growth. Environmental stresses such as salinity, cause alterations in a wide range of physiological, biochemical, and molecular processes in plants. So, identification of plants which are less affected by salinity could be of great importance in breeding programs. Kochia (Bassia scoparia) is such a crop which its high tolerance to salinity has been reported in previous studies. Since photosynthesis is the most fundamental and intricate physiological process in all green plants determining plant yield under salinity stress, the aim of this study was evaluation of the effects of salinity on photosynthetic characteristics of kochia. In order to study photosynthetic characteristics of kochia under salinity conditions, an experiment was conducted as split-plot based on randomized complete block design with three replications. Three masses of kochia including Birjand, Borujerd and Sabzevar were considered in main plots and three levels of salinity (5.2, 10.5 and 23.1 dS.m-1) as sub-plots. Photosynthesis, evapotranspiration, stomatal conductance, Sub-stomatal CO2 concentration and quantum yield of PSII were measured in the youngest fully expanded leaf for seven weeks started from thirty days after imposing stress. Chlorophyll a, b and carotenoids and green area were measured at anthesis. Data were analyzed using Minitab 16 and means were compared by LSD test at a significance level of 0.05. Results indicated that photosynthesis and evapotranspiration was decreased over the time after salinity imposed. Photosynthesis and evapotranspiration in different masses and salinity levels was almost the same in the 8th week after imposing salinity stress. At the end of the growth season, photosynthesis and evapotranspiration indicated too much decrease in all salinity levels and reached to a same level. In the 4th week after salinity was imposed, the highest photosynthesis was observed in Birjand, Sabzevar and Borujerd, respectively. Reduction intensity of evapotranspiration in time was more in Birjand compared to Borujerd and Sabzevar masses. CO2 sub-stomatal CO2 showed a pronounced increase in all masses and a salinity levels in the 8th weeks after salinity imposed. Results of chlorophyll fluorescence indices in the salinity imposing period indicated an improvement of these indices and finally the increase in quantum yield of photosystem II. Stomatal conductance showed a decreasing trend during time and reached to the lowest level in the 11th week after imposing stress. The lowest mean of this parameter was belong to Sabzevar mass. Stomatal conductance did not vary much till tenth week after imposing salinity while it got a steep slope decreasing trend in the other two salinity levels in week seven. Decreasing trend of stomatal conductance was stronger in treatments of 10.5 and 23.1 dS.m-1 compared to 5.2dS.m-1. Leaf content of chlorophyll a, b, carotenoids and total pigments at anthesis were not affected by kochia masses and salinity levels. Interaction of salinity and mass indicated a lower green area in higher salinity levels. The highest and lowest green area was observed in Borujerd mass in salinity levels of 5.2 and 23.1 dS.m-1, respectively. Results of this experiment indicated that photosynthesis and quantum yield of PSII in kochia did not vary much as salinity intensity increased. Also, content of photosynthesis pigments was not affected by salinity stress. Generally, it could be concluded that photosynthesis system of kochia is capable to maintain its normal processes although being imposed to sever salinity stress and though could be used as a model crop in plant breeding programs