In this study, the nutritive value of several important range species was investigated in semiarid rangelands of central Zagros in 2010. Sampling was performed within the 2-square-meter plots by clipping method. The important forage quality indices; Nitrogen (N), Crude Protein (CP), Ash, Ether Extract (Ee), Natural Detergent Fiber (NDF), Acid Detergent Fiber (ADF), Digestible Energy (DE), Dry Matter Digestibility (DMD), Metabolizable Energy (ME), Dry Matter Intake (DMI) and Relative Feed Value (RFV) were analyzed. Analysis of variance was used to analyze the data. The correlation between quality parameters was determined based on the relative quality index in MVSP, Mosaic, and PC-ORD software. There was a positive correlation between CP, DMD, DMI, and RFV for all species; however, a negative correlation was found between ADF, CP, and RFV. The results of the statistical analysis showed that forage quality of species (Leguminoseae and Gramineae) was significantly different (P<0. 05). Almost in all the grass species studied, the higher levels of ADF and NDF caused to reduce the forage quality of these species. In addition, based on the measured parameters, the highest and lowest forage quality were related to Cachrys acaulis (RFV=289. 46) and Agropyron trichophorom(RFV=87. 89), respectively.

In this study, we investigated the effects of jasmonate on plastidial terpenoids on Cannabis sativa at vegetative stage. We used jasmonate solutions with 0, 1, 5, 10 and 100 mM concentrations for treating plants. Plant treated with Jasmonate showed an increase in chlorophyll a content in comparison with the control plants. However, chlorophyll b content was increased only in 5 mM jasmonate treatment. Also, carotenoid content increased in all treated plants but there was no significant difference between various concentrations of jasmonate. The amount of a-tocopherol was enhanced in plants treated with 10 and 100 mM jasmonate. Treatment with 1 and 5 mM jasmonate caused a considerable increase in tetrahydrocannabinol. 5 mM jasmonate solution was more effective in this regards. Cannabidiol content was decreased in all plants treated with jasmonate. These results showed that jasmonate triggered the accumulation of primary and secondary isoprenoids in chloroplasts.

The development of crops with suitable root traits, enable them to have higher yields in soils with higher salt and limited water. The aims of this study were to determine soil water potential levels to obtain a significant root growth response and identify genotypic differences in seminal root length and root branches in response to drought stress. Three separate factorial greenhouse experiments at vegetative stage of wheat were carried out based on completely randomized design with three replications. The optimum water potential level needed to obtain a significant root growth response ranged from − 7 to − 8 bar. The results showed the genotypic diversity in root growth response to drought stress. Drought stress reduced root system growth such as seminal axile root length, two longest seminal axile roots, number of seminal roots and distance between the root tip and the first branch root by 19, 21, 37 and 46 % respectively, compared to control. The reduction of root growth traits of tolerant drought stress cultivars was less than sensitive ones. Genotypic variation in root growth response to drought stress indicates the suitable opportunities to improve drought tolerance through plant breeding.

Boron (B) is essential to growth at low concentrations and limits growth and yield when in excess. Little is known regarding plant response to excess B and salinity occurring simultaneously. In this study, two models of Leibig-Sprengel (LS) and Mitscherlich-Baule (MB), originally proposed to explain plant response to nutrients only, were modified to evaluate canola yield response to combined levels of B and salinity stresses. The water salinity treatments were consisted of non-saline water, 3, 6, 9 and 12 dS m-1. The B treatments were 0, 10, 20 and 30 mg kg-1 added to soil as H3BO3. It was revealed that modified LS model can satisfactorily predict canola dry matter yield. The calculated statistics: Maximum Error, Root Mean Square Error, Modeling Efficiency, Coefficient of Determination and Coefficient of Residual Mass, indicated that the estimated relative dry matter yield for soil B concentrations and salinity levels by modified LS model compared to modified MB model was closer to the measured relative yield. Therefore, the use of modified LS model for estimating canola relative yield in salinity and B stresses is recommended. The threshold value of salinity increased with higher B concentration and maximum dry matter yields decreased with increasing B concentration. Excess B was found to decrease dry matter yield of canola. This effect was inhibited when plants were exposed to simultaneous B and salinity stresses. Both irrigation water salinity and B concentration influenced water use efficiency (WUE) of plant, however, only B concenteration influenced canola yield in in the same manner.

Salinity is one of the limiting factors in many crops including rice production. The objective of this study was to investigate the response of 89 recombinant inbred lines derived from a cross between two Iranian rice cultivars, Tarom-Mahalli (indica) and Khazar (indica), under non-stress and 8 dS. m-1 salinity stress at vegetative stage conditions. The experiment was carried out as pod experiment under open air conditions in a completely randomized design with four replications. The results of combined analysis of variance under non-stress and salinity stress conditions showed that the the effect of line and line×stress interaction for all the studied traits was significant, indicating different reaction of the lines under two conditions. The results of simple analysis of variance also showed that the difference between lines in both conditions was significant for all traits at 1% probability level. Correlation coefficients among traits indicated that the highest correlation coefficient was observed between biomass and stem dry weight under both conditions. Stepwise regression analysis for biomass under non-stress conditions showed that root length, root to shoot dry weight ratio, number of tillers per plant at 120th day and plant height at 120th day were the most important traits influencing biomass, respectively, while under salinity stress conditions, root area and root volume in addition to these four traits, were also identified as effective traits on biomass. Factor analysis also showed that three and five independent factors explained the correlation between biomass and the other traits in the studied lines under non-stress and salinity stress conditions, respectively. Cluster analysis using Ward’ s minimum variance method under non-stress conditions divided the lines into four groups which the fourth group was consisted the lines with higher values than total average for most traits. Under salinity conditions, the lines were divided into three groups and the lines into first group had the highest biomass and the lowest genotypic score and were tolerant to salinity stress. In total, the results of current study showed that the lines 6, 9, 13, 14, 17, 18, 23, 24, 34, 39, 44, 45, 68, 79 and 80 had the higher values for most the studied traits than the other lines, in addition to higher biomass, and could therefore be considered as salinity tolerant lines in future researchs.

Drought is one of the most important abiotic stresses limiting the survival, growth, and production of plants in many regions of the world including Iran. Genetically, different species adopt different strategies to confront with drought. One of the mechanisms that plants have evolved to adapt to the environmental changes is stress memory. In this study, different genotypes of smooth bromegrass were evaluated to investigate the drought stress memory and drought stress tolerance based on a greenhouse pot experiment. Thirty three genotypes of smooth bromegrass were evaluated in three moisture environments: control (C), once drought-stressed (D2), and twice drought-stressed (D1D2) in a factorial arrangement according to the randomized complete blocks design with two replications. The dry matter yield decreased by 45 and 36% in the one-stress and two-stress treatments compared to the control, respectively. These results indicated the role of drought stress memory in modulating drought stress through the influence on forage dry yield and root dry weight. The root dry weight reduced in the once stress and twice stress conditions by 32 and 19%, respectively, compared to the control environment. This finding shows the significant effect of stress memory on the root growth. Based on the principal component analysis, superior genotypes were identified for future researches. Overall, the results suggested that smooth bromegrass is capable to activate some drought stress memory mechanisms related to morphological and root traits. Background and Objective: Smooth bromegrass is particularly adapted to areas with medium and low annual precipitations and has a high drought tolerance when compared with the other grasses. Drought is one of the most important environmental factors with adverse effects on plant growth and development and affects all morphological, physiological, biochemical and metabolic aspects of plants (Farooq et al., 2009). Therefore, it is necessary to identify drought-tolerant genotypes (Saeidnia et al., 2017b). The term stress memory was first proposed by Trewavas (2003), as the plant's ability to access past experiences to better respond to future stresses. In open-pollinated species that are difficult to develop inbred lines, such as smooth bromegrass, the main breeding method is to create synthetic varieties that are obtained through the crossing of suitable parents. Besides, half-sib matting is one of the most common methods for obtaining genetic information such as estimating the additive effects and dominance of genes (Nguyen and Sleper,  1983). Saidnia et al. (2017a) in a study on the genotypes of orchardgrass species found superior genotypes for hay production. They also examined the genetic parameters and heritability of dry matter yield and introduced the superior genotypes for the further researches. Hence, this study was designed to investigate stress memory and its effect on improving drought tolerance in a smooth bromegrass germplasm. Methods: This research was carried out from February 2017 to June 2018 in the research greenhouse located at the Isfahan University of Technology as a pot experiment. A sandy loam soil with bulk density, field capacity, and wilting point of 1. 57 g cm-3, and 12. 5 and 7. 4 %w/w, respectively, was used for filling the pots. The genetic materials included 33 genotypes of smooth bromegrass that were collected from different regions of the country and some foreign gene banks. The genotypes were investigated in three moisture environments including control (C), once drought-stressed (D2) and twice drought-stressed (D1D2) as a factorial experiment in the form of a randomized complete blocks design with two replications. Results: The analysis of variance showed that drought treatments had a significant effect on most of the traits. A significant difference was observed between the genotypes regarding the measured traits indicating high genetic diversity among the genotypes. The secondary drought stress significantly reduced most of the traits. The dry matter yield decreased by 45 and 36% in the once-stress and twice-stress treatments compared to the control, respectively. These results indicated the role of drought stress memory through the effect on dry yield of forage and root dry weight. Also, the root dry weight was reduced by 32 and 19% in the conditions of one stress and two stress compared to the control environment, respectively, which shows the significant effect of stress memory on the root system. Multivariate analysis showed that under the twice stress condition compared to the other two moisture environments, the relationships of the traits have undergone severe changes, which is a confirmation of the effect of initial stress and stress memory. Conclusions: This research indicated a high genetic diversity among the smooth bromegrass genotypes in terms of stress memory responses, which can be used in the selection methods. For example, the means of dry matter yield and root dry weight decreased to a lesser extent when grown in the presence of twice drought stress, than once drought stress. This finding shows that the mechanisms of the stress memory related to morphological and root traits in this plant are activated by applying preliminary mild drought stress and help the plant to have a smaller decrease in growth. Based on the principal component analysis, superior genotypes were identified for future research. The results of this research can be used in breeding programs and future genetic research. It is also suggested that suitable genotypes be studied more in field conditions over several years. References: 1. Farooq, M., Wahid, A., Kobayashi, N., Fujita, D., Basra, S. M. A., 2009. Plant drought stress: effects, mechanisms and management. In: Alberola, C., Debaeke, P., Lichtfouse, E., Navarrete, M., Véronique, S. (Eds. ), Sustainable Agriculture. Springer Dordrecht. pp. 153–188. 2. Nguyen, H. T., Sleper, D. A., 1983. Theory and application of half-sib matting in forage grass breeding. Theor. Appl. Genet. 64, 187–96. 3. Saeidnia, F., Majidi, M. M., Mirlohi, A., 2017a. Genetic analysis of stability in poly­crossed populations of orchardgrass. Crop Sci. 57, 2828–2836. 4. Saeidnia, F., Majidi, M. M., Mirlohi, A., Manafi, M., 2017b. Productivity, persistence and traits related to drought tolerance in Smooth Bromegrass. Plant Breeding. 136, 270–278. 5. Trewavas, A., 2003. Aspects of plant intelligence. Ann. Bot. London. 92, 1–20.

In recent years, heavy metal pollution has been one of the basic problems of the environment and the production of agricultural and medicinal plants that compounds such as jasmonate in plants can be effective in modulating this stress. In order to investigate the effect of jasmonate and lead on some physiological and biochemical traits of the medicinal plant Dracocephalum Moldavica L. under the application of vermicompost, a factorial experiment was conducted in the form of a completely randomized design with three replications. The treatments included lead at five levels (0, 100, 200, 300, and 400 mg/kg soil) and jasmonate at four levels (0, 50, 100, and 150 mmol L-1) in the conditions of non-application and application of 10 tons per hectare of vermicompost. The traits investigated in this experiment included fresh and dry weight of shoot and root, the ratio of shoot to root dry weight, leaf area and the amount of carbohydrate, proline and  catalase in plant leaves. The results showed that in the vegetative growth stage of Dracocephalum Moldavica, with increasing jasmonate concentration, the fresh and dry weight of shoot and root increased, so that the highest amount of fresh and dry weight of shoot, dry weight of root and total weight of the plant was obtained in 150 mmol L-1 jasmonate treatment. In both vegetative, and reproductive stages, different levels of lead had a significant effect on the fresh and dry weight of vegetative organs, and with the increase in lead up to 300 mgkg-1, fresh and dry weight of shoot, root and fresh weight of the whole plant, showed a significant decreasing trend. The application of vermicompost also significantly increased the fresh and dry weight of shoot, the dry weight of the root and the fresh weight of the whole plant in the reproductive stage. With the increase of jasmonate levels, the amount of leaf carbohydrate first showed an increasing trend and then decreased. Also, with the increase in lead concentration, the average carbohydrate signifi cantly increased. With the increase in the amount of applied jasmonate, the average leaf proline also decreased at first, but at higher levels, the value of this parameter showed an increasing trend. Also, with the increase in lead level, the average leaf proline found a significant non-linear increasing trend. In general, the investigation of the triple effect of jasmonate, lead, and vermicompost on the studied traits showed that the highest amount of carbohydrate and proline in the vegetative growth stage were respectively in combined treatments of 100 mmol.l-1jasmonate, 200 mg.l-1 lead without applying vermicompost and 0 mmol.l-1 jasmonate, 400 mg.l-1 lead without applying vermicompost was obtained. In the reproductive growth stage, the highest amounts of carbohydrate and proline were obtained in the combined treatments of 0 mmol.l-1 jasmonate, 300 mg.l-1 lead without applying vermicompost and 150 mmol.l-1 jasmonate, 100 mg.l-1 lead without applying vermicompost. In general, in the mean of investigated lead levels with the increase of jasmonate and the application of vermicompost, the amount of lead in the plant organs showed a decreasing trend.

Environmental stresses such as salinity have a great impact on the amount and quality of secondary metabolites of medicinal plants. To investigate the effect of salinity on phytochemical attributes of cannabis (Cannabis Sativa L. ), an experiment in the form of a randomized complete block design with three replications and 5 salinity treatments (0, 2, 4, 6 and 8 dS/m) was conducted in 2019 in medicinal plants research center, Karaj, Iran. In this study, the amount of potassium (K) and sodium (Na) elements and chlorine (Cl) in leaf and root organs of the plant were measured by a flame photometer and colorimetric method, respectively. The content of cannabinoids compounds in leaves including tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabichromene (CBC) were measured by GC/MS. The results showed that there was a significant difference (P≤0. 01) among different salinity treatments in terms of Na, K, Cl and cannabinoids THC, CBD and CBC. With increasing salinity level, the amount of Na and Cl ions in leaves and roots increased compared to the control treatment and the highest amount of leaf and root Na (15. 81, 14. 06 mg/g, respectively) was observed in salinity treatment of 8 dS/m. Also, increasing the salinity concentration caused a decrease in leaf and root K of the plant and the highest amount of leaf and root K (34. 83, 34. 46 mg / g, respectively) was related to the control treatment. The highest amount of THC and CBD (7. 94 and 1. 45 mg / g of dried plant, respectively) at salinity concentration of 4 dS / m and the highest amount of CBC at salinity of 2 dS / m (0. 012 mg / g dry leaf) were obtained. Therefore, salinity changes the amount of cannabinoids in cannabis and the highest levels of THC, CBD and CBC are obtained at low salinity levels.