Environmental Stresses in Crop Sciences
Year:2018 | Volume:11 | Issue:2 |Papers Count:20

Background and objectives: Rice can be irrigated like wheat and corn as an aerobic plant (1). There is a negative relation between the grain yield and quality, has various indexes in the world like Iran where the rice with long and separate seeds is preferred (2). The important factors of reducing the rice quality are increasing immature seeds, cracks on the surface, narrow and thin seeds (3). With regard to water crisis, it’s essential to increase knowledge level and awareness about water tension loss effects on qualitative and quantitative traits of seeds. This study aims at realization of this purpose and reducing the negative effects of water tension.Materials and methods: An experiment was carried out to study of irrigation regimes on rice genotypes grain milling quality (Total rice recovery, degree of milling, but hull, brane, head rice, broken rice, grain width, grain length, grain length after cook and grain yield) of Khuzestan province in a split-plot arrangement using randomized complete blokes comlete bloks design with three replications in two cropping seasons (2014 and 2015) at Shavoor Agricultural Research Station, Dependent in Research Center of Agricultural and Natural Resources of Khuzestan. For exposing rice genotypes to four different irrigation regimes (1, 3, 5 and 7 days), and 12 genotypes were randomized in sub-plots. The variance and correlation analysis were carried out by using the SAS and SPSS software after ensuring the normality of the data and the mean of the data was compared to a through the Tuke test.Results and discussion: The results of combined analysis of variances showed that the apart from the percentage bran and grain width that represents of them the sum was a significant different in irrigation regimes by genotypes interaction in all of trades. On the other hand, the related irrigation regimes, genotypes had different reaction. Such that past of the grain width and length decreased with increasing stress, because of adaptability genotypes and more favorable moisture, the highest of grain yield, total milled rice recovery, degree of milling, and head rice were in second irrigation regimes. But hull, bran and broken rice percentage had the lowest amount. Whereas there were a significantly positive and negative correlation between these traits and grain yield.Conclusion: Totally, the results of present study showed that traits of seed quality and quantity in the second irrigation regime has the most suitable reactions in terms of reducing crust and bran as well as increasing desirable traits like efficiency conversion degree and rice. And also, they showed the role of irrigation management with regard to genotype diversity. These results indicated that the seed yield and desirable trait in the thirds irrigation with five-day irrigation have no significant relation with flooding irrigation. It can be used as a suitable method and approach to increase irrigation efficiency of aerobic rice genotypes.

Increasing crop production to ensure future food security while reducing environmental pressure on agro-ecosystems requires improved water and nutrient use efficiency. the arid and semiarid regions of the world lack of sufficient water supply is the major problem for corn cultivation and is a restriction for its production, so studies on the growth limitation and germination of corn seeds under drought conditions seems very necessary. The effects of drought on plant growth depend on several factors such as plant genetic resistance, stage of growth and duration of plant expose to drought. The AMF are playing a vital role in sustainable agriculture because they enhance plant water relations, which improve the drought resistance of host plants. It is important to increase our understanding of AM fungal and maize genotype interactions and water condition on the symbiosis, and on the physiology and nutritional status of maize plants. Thus Mycorrhizae application and choosing suitable cultivar are of simple managements in decreasing drought effect. This investigation had done in order to investigate effect of irrigation regimes (irrigation after 70, 110 and 150 mm evaporaation from evaporate basin), Mycorrhizae (non application and application of Mycorrhizae) and cultivar (704 and 640) on growth and yield of maize. A split factorial experiment based on randomized complete block design with three replications was conducted during growing season of 2015 at Islamic Azad University, Malekan Branch, Plots were then furrow irrigated in the mornings every week. Each block was including 12 plots. The size of each plot was 3.5m×4m, and there was in each plot, 5 rows with a distance of 75 cm, and the length of 4 m. The distance between plots was selected 150 cm, and the distance between blocks was selected 3 m. By mid August an area of 2.5 m from 3 line of plot area was separately harvested and traits were evaluated. MSTAT-C and EXCEL were used to analyze data and draw graphs, respectively. Based on results of this investigation, response of cultivars to drought were different. In irrigation after 70 mm evaporaation from evaporate basin in 704 cultivar highest grain yield observed. In cultivar 704 both irrigation after 110 mm evaporaation from evaporate basin and irrigation after 150 mm evaporaation from evaporate basin decreased grain yield by 19 and 50.6 % in grain yield, but in 640 cultivar that had higher grain yield in control than 704, drought did not had significant effect on grain yield. Mycorrhizae also increased grain yield by 25.2 %. All three factor of drought, Mycorrhizae and cultivar caused changes by changing both yield component of grain number and 100 grain weight. It seems drought caused a decrease in grain number by decreasing number of total floret and increasing unfertile floret number, but Mycorrhizae had opposite effect that this decrease in floret number can caused by gap increase between tasseling and silk emergence. Drought did not had effect on chlorophyll a, but it decreased chlorophyll b, but Mycorrhizae caused an increase in chlorophyll b. Drought and Mycorrhizae increased catalase and Peroxidase content. We then suggest potential areas for future research related to (a) the adoption of cropping practices promoting AM colonization and survival; (b) the further understanding of AM effects on maize morpho-physiology; and (c) the creation of AM-colonized, drought-tolerant maize cultivars through conventional breeding as well as molecular and genomic techniques.

Introduction: Durum wheat (Triticum turgidum var. durum) is grown for human consumption, mainly as pasta products, e.g., spaghetti and macaroni, couscous, bulgur, frike, flat breads, etc. Worldwide, the area annually planted to durum wheat is estimated to be around 17-18 million hectares, i.e., 8 percent of total wheat area, with a production averaging about 30 million tons annually, which is 5.5 percent of total wheat production. Although durum is grown in various regions of the world, the great bulk of durum area and production is concentrated in the Mediterranean basin and North America. Eight countries (Algeria, Canada, Italy, Morocco, Syria, Tunisia, Turkey, and USA) account for nearly two thirds (2/3) of world durum area and production. In Iran, the area under durum cultivation is about 400-500 thousands hectares with an annual production of 400-500 thousand tons, which covers about 60% of country demands. In spite of the importance of durum for Iranian rural economies, the country has not all succeeded in its research and development efforts to substantially improve durum productivity. The combinations of increasing demand for durum and durum products, as a result of demographic pressure, and relatively low durum productivity partly due to abiotic stresses (i.e. cold, terminal heat, moisture and nutrient deficiency stresses) made the country to an importer of durum. These are frequently exacerbated by biotic stresses, e.g., diseases and insects that may severely inhibit crop growth.Materials and methods: The main purpose of this study was to achieve high yielding durum wheat genotypes with higher yield stability in different environmental condition, tolerance to environmental stresses such as cold damage, drought and end of season heat stress. Hence, 17 durum wheat lines were evaluated for grain yeild and morphlogical traits in Maragheh, Sararood, Qamloo, Ardabil and Shirvan agricultural research stations in 2011-14. In each location, the experiments were conducted in a randomized complete block design with three replications.Results and discussion: Based on combined ANOVA, there was significant difference among the environments, genotypes and G×E. GGE-biplot models showed that the 5 environments were belonged to 3 mega-environments, and different genetopes had higher yield in each mega-environments. Sumplimentary irrigation, at sowing time and flowering growth stages, could increase grain yield of lines 30 and 70 percent in Maragheh and Qamloo locations, respectively. The increase of grain yield was 42 percent for line Rascon under suplimentary irrigation. The AMMI and GGE results also confirmed genotype 5 was the most high-yielding durum line with reasonable yield stability in cold areas (Maragheh, Qamloo and Ardabil). Also, genotype 13 was the most high yielding and stable line in Sararood. Hence, these line can be candiatted to release new durum varieties for cold and moderat rainfed areas. Complementary irrigation could increase grain yield up to 30 and 70 percent in Maragheh and Sararood, respectively.Conclusions: It can be concluded that finding of new stable high-yielding durum lines, with better performances than that the existed varieies, is a great progress in durum breeding programs in cold rainfed areas. Both GGE biplot and AMMI analyses could be used in grain yield stability and adaptability under rainfed conditions and sumplementary irrigations, however, the results of GGE biploet were more applicable and can be use extensively in the study of grain yield adaptability and stability under rainfed and sumplementary irrigations conditions in durum wheat breeding programs.

Introduction: Drought, environmental stress is the most common, that about 25 percent of the acreage limit, the occurrence of stress significantly reduced biological yield, grain yield, harvest index and water use efficiency is sometimes. Although the Barley is more tolerant to drought than other cereals, but this plant during its growth and development, in both stem elongation and grain filling sensitive to water deficit, and drought in the steps leading to the reduction of its performance. Flowering stage, the most sensitive growth stage of barley to drought that Water deficit at this stage caused reduces the fertile florets and thus reduce the number of grains per spike. Drought stress from pollination to maturity stage by intensifying the aging of leaves, reduced growth and reduced grain filling rate is decreased average grain weight and grain yield. This research in order to study the yield of barley genotypes in normal irrigation and drought stress conditions as well as analysis of the relationships between traits and grain yield was conducted.Materials and methods: The experimental was conducted under normal irrigation and drought stress conditions during 2013-2014 in a RCB design with three replications in college of agricultural, Shiraz University. The plant material used including eight foreign genotype and two Iranian cultivars (cultivar tolerant of Joseph and Reyhan as susceptible), respectively. All the planting, watering and harvesting, but to be quite similar for both experiments were conducted.In normal condition, plants until the end of the growth phase to field capacity (FC) were irrigated, while in drought stress condition, plants were irrigated to field capacity and then drought stress during flowering size for irrigation was applied. To determine the amount of water required in each irrigation of moisture content in soil was used. At the end of the growth phase and after physiological maturity, plant height, the length of the spike, the number of grains per spike, number of grains per spike, grain weight, grain yield, biological yield and harvest index were measured. Statistical analysis was performed using SAS software MINITAB and averages were compared by Duncan's test at 1%.Results and discussion: The results showed that in both drought stress and normal irrigation conditions, there was a significant differences between genotypes in terms of spike length, height, the weight of 1000 grains, grain per spike, spike per meter2, grain yield, biological yield and harvest index. The highest grain yield under irrigation conditions were belonged to genotypes 79, 95 & 120 and Yousef cultivar (with average yield 935.3 g/m2) and under drought stress conditions belonged to genotypes 95 and 120 (average yield 834.3 g/m2).The highest positive correlation under normal irrigation condition belonged to biological yield (0.94), the number of spike & grain per spike (0.51) and under drought stress conditions belonged to biological yield, the weight of 1000 grains and the number of grain with 0.96, 0.65 and 0.63 respectively. In the regression model were important traits under normal irrigation condition, including spike length, biological yield and harvest index with coefficients of determination 0.998, 0.920 & 0.995 respectively, and under drought stress condition, biological yield and harvest index with coefficients of determination 0.935 & 0.995 respectively.Overall under both environmental conditions, the genotypes 95 (with average yield 8809.7 kg/ha-1) and 120 (with average yield 8925 kg/ha-1) as the best genotypes were identified.Conclusion: There are significant differences among genotypes for yield components in order to help researchers select for breeding programs could be helpful. Analysis of variance in both normal and drought conditions showed the same traits were assessed. Genotypes in terms of irrigation were significant differences in the characteristics assessed that this proves that the variation between the genotypes under different irrigation.

Introduction: Drought stress conditions are the most important factors in yield reduction of crops in the world. Breeding of cultivars with high tolerance to these stresses and satisfactory yielding are considerable. In order to evaluate the resistance of test cross hybrids of sugar beet (12 hybrids and two control cultivars) to water stress (200 mm evaporation of A class pan) in field conditions were used randomized complete block design with three replications in Khorasan Razavi Agricultural and Natural Resources Research and Education Center.Materials and methods: This experiment was carried out in 2015 in a randomized complete block design with 14 test cross genotypes of sugar beet includes six monogerm hybrids (mono s1, mono s2, mono s3, mono s4, mono s5 and mono s6) and six multigerm hybrids (multi s1, multi s2, multi s3, multi s4, multi s5 and multi s6) with two control cultivars (Pars and Motahar) in three replications. In this research, traits such as root yield, sugar yield, sugar content of root, leaf number, temperature difference between leaf and air, succulence index, leaf relative water content, specific leaf weight, leaf color score, leaf growth score, postural leaf, root growth score and ratio of length to width of root were measured. Data were analyzed using SAS 9.1 software. After standardizing data, cluster analysis for sugar yield was done with WARD method and Square Euclidean distance coefficient. Factor analysis was performed using the software Minitab version 15. The analysis of variance on test data and comparison to the middle of the LSD test was performed at the 5% and 1% level.Results and discussion: The results showed that there were significant differences (p≤0.01) between studied genotypes for all traits except for temperature difference between leaf and air, postural leaf, root growth score and ratio of length to width of root. The control cultivars of sugar beet (Pars and Motahar) did not showed superior than the other genotypes for most of traits studied and those have the average values of traits. Multi s5 genotype showed superiority for root yield, succulence index, leaf relative water content, specific leaf weight, leaf growth score and root growth score than the other genotypes and in other words, has a high potential for drought tolerance. The highest heritability (89.40 %) estimated for leaf number, suggested that the influence of environmental effects on this trait. The highest standard heterosis in hybrid Multi s5 was obtained for most of studied traits. In this research, there were significant positive correlations between root yield and sugar yield. Significant and positive correlations were observed between root yield and root growth score. While, significant and negative correlations were obtained between root yield, sugar content of root and leaf number. The dendrogram generated from the cluster analysis for sugar yield classified genotypes into three main groups. Factor analysis led to five loading factors which explained 91.3 percent of total variation.Conclusions: In general, the results showed that there are considerable variations in yield, morphological and physiological traits among test cross genotypes of sugar beet due to the potential for drought tolerance in them.

Introduction: Chickpea (Cicer arietinum L.) is an annual grain legume or “pulse crop” that is 2th legume after soybean in the world and was cultivated in 60 country. Legume, spatially chickpea is the most important tolerant crop in arid and semi-arid country in western of Asia such as Iran. Chickpea can growth in poor soil and undesirable environment conditions. Drought is an important factors that influencing chickpea production and quality. As area of cultivation is in dryland conditions thus aim of researches is reach to tolerant genotypes. The objective of current study was to evaluate the genetic variation and drought resistance advanced genotypes in chickpea Materials and methods For investigation of genetic variation and drought resistance, 64 advanced genotypes were evaluated in a simple latis (LD) with two replications under normal and drought stress conditions in deputy of Dryland Agricultural Research Institute of Kermanshah during 2013-2014 cropping season. Plant spacing was as plots with four rows in 4 m in length, 30 cm apart. The seed were sowed in row with 10 cm distance and the seeding rate was 33 seeds per m2 for all plots. At maturity stage after separation of border effects from each plot, grain yield was measured. Statistical analysis was performed using SAS, SPSS and STATISTICA packages. some drought resistance indices such as mean productivity (MP), geometric mean productivity (GMP), harmonic mean (HAM), stress tolerance index (STI), stress susceptibility index (SSI), yield index (YI), K1 and K2 were measured based on yield in both conditions. Also we used stress tolerance score (STS) method for selection genotypes according to all indices.Results and discussion: Study on correlation between Yp, Ys and drought resistance indices showed that Yp and Ys had positive and significant correlated with MP, GMP, STI, YI, HAM, K1 and K2 thus these indices were the most suitable drought tolerance criteria for screening of chickpea genotypes and STI was used for 3D graph. According to drawing of 3D graph and bi-plot, the genotypes were placed into tolerant and non-tolerant groups, as genotypes FLIP 08-42C, Azad, Adel and FLIP 08-35C were placed near to MP, GMP and STI vectors and A group in area with high yield potential and low sensitive to drought. Also according to results of stress tolerance score (STS) method, above genotypes were selected as tolerant genotypes. For more understanding and visualizing the relationships between calculated indices and genotypes performance, principal component analysis (PCA) was performed. Result of this analysis showed that the first two components explained more than 98% of the total variance.Conclusions: Finally, this high variation between studied genotypes could use in breeding program for reached to drought tolerant genotypes.

Introduction: Maize is the cereal with the largest annual global production at 1000 M tons annually. Maize (Zea mays L.) along with wheat and rice provides at least 30% of the food calories to more than 4.5 billion people in 94 developing countries where one-third of world children are malnourished. By 2050, the demand for maize in the developing will be almost double to the current demand. However, an estimated 15% to 20% of maize grain yield is lost each year due to drought and such losses may further increase as droughts become more frequent and severe because of climate change. Cultivation area for maize grown in Iran was about 350000 ha with 1.25 million tons production in 2014. But drought stress in recent years and poorly water sources could limit maize cultivation in Iran.Materials and methods: In order to evaluate of drought stress effects on yield and it’s components in some maize hybrids, also determine drought tolerant genotypes, 8 maize hybrids was studied as three experiments under normal, drought stress in vegetative stage and drought stress in reproductive stage. Experiment was conducted using RCBD design with three replications in training field of Kermanshah education center. Some agronomic traits such as plant height, ear per plant, ear length, ear diameter, ear cob diameter, row per ear, seed per ear, 100 seed weight, grain yield based on 14% moisture, ear weight, ear cob weight, seed depth, leaf area, stem diameter and days to physiological were recorded. Because of numerous recorded traits, in result and discussion section just some of most important yield components have been explained.Results and discussion: Analysis of combined variance showed that drought stress had significant effect on all recorded traits. Some yield components such as 100 seed weight, seed per row and rows per ear reduced mostly due to drought stress. Above traits due to drought stress reduced 25.6, 19.1 and 17.6 percent, respectively. Among evaluated traits, drought stress reduced grain yields more than any other traits. In fact, cumulative reduction in component yield caused significant reduce in grain yield. Then grain yield under drought stress in vegetative and reproductive stages reduced 13.7 and 28.7 percent, respectively. Maize hybrids were different statistically for all recorded traits. Hybrids Ksc260, Ksc704 and Ksc647 had high grain yield under both normal and drought stress conditions. Drought tolerance indices confirmed above issue so that these hybrids had high potential for grain yield also partial drought tolerance. Among above hybrids, Ksc260 had well characteristics to cultivate in regions with drought stress conditions.Conclusions: Among evaluated traits, drought stress reduced grain yields more than any other traits. In fact, cumulative reduction in component yield caused significant reduce in grain yield. There were well variation among evaluated hybrids and it could be identify some drought tolerant hybrids among them. Among evaluated hybrids, Ksc260 with high grain yield under normal and drought stress conditions also early maturity had well characteristics to cultivate in regions with drought stress conditions. Besides Ksc260, Hybrid Ksc704 had high grain yield under both conditions but this hybrid is ale maturity and it, s water requirement is more than Ksc260 so it suggested that Ksc704 cultivated in areas with no water limited.

Introduction: Biotic and abiotic stresses has always been a concern in agriculture. The response of plants to inevitable environmental stresses in various stages of growth and development, will be a good strategy for plants initial assessment in confronting with adverse conditions and their productivity. In situation of the food crisis, vegetables increased production as a relatively cheap source to provide the daily needs of people to vitamins, minerals and active compounds against cancer and premature aging has been considered by many researchers. Identify the expectation or tolerance of plants and use of this capacity in unfavorable conditions is one of the primary ways when we have no choice sa saline soils or overpopulation. Chard plant (Beta vulgaris var. Cicla), belonging to Amaranthaceous family, that its effectiveness properties in reducing heart attacks, diabetic, colon and prostate cancer has been proven can be examined. Increasing production by creating conditions free of tension, especially in the early stages of plant growth is possible. Irreparable damages of plants production amount by biotic and abiotic stresses in the environment is always observed. This study aimed to determine the optimal conditions and effect of some environmental stresses such as salinity, drought and temperature on seed germination and seedling growth of chard plant.Materials and methods: Some separate trials as completely randomized design (only drought and temperature as factorial) with three replication in horticulture laboratory of University of Jiroft was conducted. The effect of constant temperatures, alternating temperatures, hydropriming, salinity, acidity and drought stresses on germination indexs such as germination percentage, germination speed, seed vigor, seedling growth and chemical compositions of plant changing (proline content and antioxidant enzymes activity) under some stresses were measured.Results and discussion: The results of this search showed that minimum temperature during seed germination 1.92±1.24, optimum 25±0.74 and maximum were 45.84±1.67°C. The maximum germination rate was observed in alternating temperature 20/100C.18-hour hydropriming (washing with running water) of seed compared to control had an significant effect on germination seed. (P<<0.05).The level of salinity decreased the germination percentage to 50% was 187±7.4 mM. Changing the acidity from 7 to 5 and 9, respectively, decreased germination percentage up to 28.3 and 15% respectively. Base water potential to stop germination was estimated -0.96, -0.80 and -0.78 Mpa in temperaters 250C, 200C and 150C respectively.Conclusion: According to this research, it seems that chard plant is not a demanding one with hypersensitivity in seed germination stage and primary growth and can germinate and growth in saline environments and this susceptibility apart from its high nutritional value can investigate further and used in various fields.

Introduction: Water potential osmotic is one primary environmental regulators of seed germination. Quantification of germination response to water potential is possible using hydro time model, also low seed germination and seedling emergence is one of the main problems in dry areas. In this study, application of hydrothermal time models on the basis of normal, weibull and gumbel distributions for quantification of Carthamus tinctorius germination response to water potential.Material and methods: Treatments included drought levels (0, -0.2, -0.4, -0.6 and -0.8 MPa) and priming (Priming with GA 50 ppm for 15 h at 20oC and control seeds). Three replicates of 25 seeds were used for each temperature. A seed was considered germinated when its radicle protruded through the seed coat at least 2 mm. Cumulative germination response of seeds to differential water potential were quantified using three-parameter sigmoidal model, then, germination response of seeds was quantified using hydro time model (normal, weibull and gumbel distributions). The akaike information criterion (AICc), root mean square of errors (RMSE) and coefficient of determination (R2) and relationship between the observed and the predicted germination percentage and base water potential were used to select the superior model from among the employed methods.Results: Germination percentage and time to 50% maximum seed germination of Carthamus tinctorius were calculated for the different treatments seed (Priming with GA 50 ppm for 15 h at 20 °C and control seeds) by fitting 3-parameter sigmoidal functions to cumulative germination data. Results indicated that germination percentage and germination rate reduced as a result of water potential increment but increased with priming. The highest germination percentage was obtained from control and -0.2 MPa osmotic potential and priming seed (97.32 and 97.30 %). The minimum time to 50% maximum seed germination was obtained from control osmotic potential and priming seed (0.66 seed per day). Results indicated that normal (Akaike information criterion for control and priming seed was -240.76 and -241.50 respectively and root mean square of errors for control and priming seed was 0.114 and 0.111 respectively) and weibull (Akaike information criterion for control and priming seed was -232.34 and -240.53 respectively and root mean square of errors for control and priming seed was 0.113 and 0.110 respectively) hydrothermal time models more accurately predicted germination than gumbel (Akaike information criterion for control and priming seed was -254.10 and -247.40 respectively and root mean square of errors for control and priming seed was 0.121 and 0.118 respectively) hydrothermal time model. According to the hydro time models, the hydro time constant (θH) estimated with normal, weibull and gumbel distributions was 1.11, 1.01 and 1.11 respectively for control seed and 0.92, 0.91 and 0.94 MPa d-1 for priming seed. Base water potential estimated with normal (ψb (50)), weibull (median) and gumbel (median) distributions was -0.79, -0.93 and -0.86 MPa respectively for control seed and -0.79, -0.93 and -0.86 MPa for priming seed. The shape parameter (l) of the Weibull hydrothermal time model for control and priming seed was 1.65 and 1.45 respectively, which implied asymmetry of base water potential data and skewness of distribution to the right. Based on the Weibull hydrothermal time model, water potential threshold for the onset of germination (location parameter of weibull hydro time model (m) or yb (0)) for control and priming seed was equal to -1.71 and -1.95 MPa.Conclusion: Using hydro time model in order to quantify the germination response of Carthamus tinctorius seeds to different water potential and priming resulted in satisfactory outcomes. Due to the flexibility of the Weibull distribution, this model provides a useful method for predicting germination and weibull distribution may be more suitable than the normal distribution for seed germination modeling.

Introduction: Seed germination is a complex biological process that is influenced by various environmental and genetic factors. Temperature and water potential are two primary environmental regulators of seed germination. Quantification of germination response to osmotic potential and temperature is possible using non-liner regression models. Tall mallow (Malva sylvestris) is an important invasive weed in southwest Iran and also a medicinal plant.). Tall mallow is native home in Western Europe, North Africa and Asia. This plant frequently found in cultivated fields, orchards, gardens, farmyards near manure piles, along roadsides, in towns, and in waste places and, can grow anywhere from 60 to 120 cm in length. Not published information exists concerning effect of osmotic potential on cardinal temperatures, Therefore, the objective of this research was to evaluate the effect of osmotic potential and different temperatures on germination and determination cardinal temperatures (base, optimum and maximum) of Malva sylvestris under osmotic stress.Material and methods: In this study germination response to water potential in different temperature were studied. Treatments included osmotic levels (0, -0.2, -0.4, -0.6 and -0.8 MPa) and temperature (5, 10, 15, 20, 30, 35 and 40oC). Cumulative germination response of seeds to differential water potential and temperature were quantified using three-parameter sigmoidal model. For quantifying response of germination rate to temperature for different osmotic potential were used of 3 non-linear regression models (segmented, dent-like and beta). The root mean square of errors (RMSE), coefficient of determination (R2), CV and SE for relationship between the observed and the predicted germination percentage were used to select the superior model from among the employed methods. Germination percentage and time to 50% maximum seed germination of Malva sylvestris were calculated for the different temperatures and osmotic potential by fitting 3-parameter sigmoidal functions to cumulative germination data.Results: Results indicated that temperature in addition to germination percentage also on germination rate was effective. Also results showed that germination percentage and germination rate increased with increasing temperature, while germination percentage and germination rate reduced as a result of water potential increment. Results indicated that under different osmotic potential as 0, -0.2, -0.4, -0.6 and -0.8 MPa, the segmented model estimated base temperature as 1.46, 1.82, 1.29, 0.43 and 4.06 °C, the dent model estimated base temperature as 1.23, 1.82, 3.04, 2.63 and 4.07 °C, the beta model estimated base temperature as -4.32, 4.46, 1.86, 1.61 and 4.13 °C, the segmented model estimated optimum temperature as 28.29, 27.58, 22.24, 22.51 and19.69 °C, the optimum temperature using beta model as 27.89, 25.41, 23.18 and 21.05 °C, the dent-like model estimated lower limit of optimum temperature and upper limit of optimum temperature as 23.16 and 33.58, 16.86 and 30, 16.1 and 25, 15.81 and 25, 19.51 and 1987 °C, ceiling temperature using segmented model were 42.9, 40, 40, 40 and 34.96 °C, using dent-like model were 42, 40, 40, 40 and 34.96 °C, using beta model were 42.01, 40.02, 39.96, 39.98 and 34.83 °C, the segmented model estimated fo as 13.87, 18.45, 19.43, 25.24 and 36.13 h, the dent-like model estimated as 16.65, 23.28, 23.43, 30.48 and 36.56 h and using beta model were 16.06, 21.34, 22.21, 28.92 and 42.89 h, respectively. In compared 3 models according to the root mean square of errors (RMSE) of germination time, the coefficient of determination (R2), CV and SE the best model for determination of cardinal temperatures of Malva sylvestris for 0 to -0.6 MPa was dent-like model and for -0.8 MPa was segmented model. In general, results indicated that lower limit of optimum temperature and upper limit of optimum temperature and ceiling temperature reduced but fo increased as a result of water potential increment.Conclusion: Germination of Malva sylvestris response to different temperatures and osmotic potentials, led to acceptable results. Utilizing the output of non-liner models at different temperatures can be useful in prediction of germination rate in different water potential.

Introduction: Dragonhead or Moldavian Balm (Dracocephalum moldavica L.) is an annual medicinal herbaceous and aromatic plant that its essential oil is used widely in medicine, food, cosmetic and health industries, which is belong to Lamiaceae family. Due to the importance and role of medicinal plants in various industries, there is an increasing demand for herbal medicines. But nowadays water deficit is known as an important environmental factors that affecting plant growth, yield and production, especially in arid and semi-arid regions. In order to reduce the adverse effects of drought stress in arid and semi-arid regions, it is necessary to provide strategies to reduce the drought damages. Seed bio priming is one of the techniques which enhance the growth of plants and their resistance against adverse environmental conditions. Some studies show that the use of some microbial species that are collectively designated as plant growth promoting rhizobacteria (PGPR), can improve yield and quality of medicinal plants. Given the importance of medicinal plants, adverse effects of drought stress and beneficial effects of some seed microbial inoculation as seed bio priming, this study aimed to investigate the effect of PGPRs on the morphological indices of Moldavian Balm under water deficit conditions.Materials and methods: This pot experiment was conducted in a factorial experiment based on completely randomized block design with three replications. Traits involving three levels of drought stress (100 % of full irrigation (as control), 75 and 50 % of full irrigation) and seed inoculation with 8 levels of PGPRs (without inoculation (as control), and inoculating with Mycobacterium sp., Rhodococcus sp., Pseudomonas putida, Bacillus sp., Azotobacter sp., Pseudomonas fluorescence and Corynebacterium sp.). Bacteria were obtained from the Biotechnology research center of Shahrekord University, Iran. One seed lot of Moldavian Balm cv. SKZ-1 was used in this experiment. Seeds were surface-sterilized in 1.5% NaOCl for 5 minutes. For each of bacterial treatments, surface-sterilized seeds were soaked in the relative bacterial suspension (approximately 5 × 108 cfu.ml-1 suspensions) for two hours. Ten seeds sowed into each similar size pots were filled with 5000 gr field soil. A sample of soil was sent to laboratory for determining of chemical and physical characteristics. After germination and at 3-4 leaf stage, seedlings were thinned down to 3 plants per pot. Drought stress treatments were implementing from 3-4 leaf stage and continued to harvest.Results and discussion: The results showed that the effects of drought stress and bacterial treatments on all studied traits and their interactions on some traits such as leaf area, leaf dry weight, shoot dry weight, root volume and area was significant. Overall, with increasing of drought stress severity plant height, stem diameter, number of lateral branches, number of flowering branches, leaf area and leaf dry weight, root volume and area was decreased, significantly. But this decline showed lower rate in bacterial treatments. The bacterial treatments showed a significant increase in plant height, stem diameter, root dry weight and length, leaf area and leaf dry weight compared to control. The most plant height was found in Mycobacterium sp. and Pseudomonas putida, inoculated treatments that increased plant height by 29.3 and 26.3 percent compared to control. All bacterial treatments could increase the number of lateral branches and number of flowering branches compared to control. Although difference between Corynebacterium sp. inoculated treatment and control was not significant. The highest number of lateral branches was found in Mycobacterium sp. and Pseudomonas fluorescence inoculated treatments that increased the number of lateral branches by 21 and 15 percent compared to control. The highest number of flowering branches was found in Mycobacterium sp. inoculated treatment that increased the number of flowering branches by 29.6 percent compared to control. The effects of bacterial treatments on leaf area and leaf dry weight were affected by different levels of drought stress. Overall, in the absence of the bacterial inoculation the highest leaf area was observed in full irrigation treatment and in 75 and 50 % of full irrigation treatments decreased by 27.5 and 47.9 percent compared to full irrigation treatment, respectively. The reduction trend of leaf area under drought stress treatments was also observed in other bacterial inoculation treatments. But the difference was that bacterial treatments could mitigate the effects of drought stress.Conclusions: In conclusion, this experiment results showed that bacterial treatments had positive effects on all morphological studied traits, especially under water deficit stress conditions. Mycobacterium sp., Bacillus sp., Pseudomonas fluorescence and Azotobacter sp. were more affective in morphological studied traits. These bacterial treatments could reduce the harmful effects of drought. Since, based on these results, the use of Mycobacterium sp., Bacillus sp., Pseudomonas fluorescence and Azotobacter sp. bacterial inoculation treatments, as seed bio-priming, can be recommended for improving of morphological indices of Moldavian Balm especially under water deficit stress conditions.

Introduction: Soil salinity is one of the major abiotic stresses affecting crop growth and productivity. Effective screening techniques for salinity tolerance would be beneficial in developing yielding wheat varieties. Knowledge of the interrelationships between traits will improve the efficiency of breeding programs especially under saline conditions through appropriate selection criteria. Improving the seed yield of wheat is always the final and major target in plant breeding.. On other hands, Yield is a complex quantitative trait, with low heritability. Some morphophysiological traits and related characters with seed yield due to easy measurement and high heritability can be used as criteria for distinguish salinity tolerant plants and for improvement of seed yield in wheat genotypes. Therefore, there is necessary to examine the relationships between various traits, especially between seed yield and other traits. Biplot is a graphical tool for breeders and is a plot that simultaneously displays the effects of traits and genotypes. The GGE biplot is the most commonly used and most useful type of biplot. The first objective of this study was to describe a genotype by trait (GT) biplot, which is an application of the GGE biplot technique to study of the genotype by trait data and to examine its usefulness in visualizing wheat trait relationships, and its application in M5 lines evaluation, comparison, and selection. The second objective of this study was to evaluating salt tolerance of M5 bread wheat lines clarify the association among some morphophysiological traits of M5 bread wheat using correlation and factor analysis, which provide valuable information for breeding new high yielding wheat lines.Methods and Material: IN this study, 15 bread wheat line selective of 4 generation (M4) lines with 2 parents genotype of them (Arg and Bam) and 2 genotype yazd (Sivand and Narin) were evaluated under two non-stress) 2 dSm-1) and stress conditions) 10 dSm-1) in a Randomized Complete Block Design (RCBD) with three replications research field of the National Salinity Research Center (NSRC) in Yazd provinc. Each plot consisted two rows 20 cm apart and 1 m in length. for the purpose of determining the salinity of soil during growth season, sampling have been done from the depth to 90. The average of salinity rate in non-stress and salinty condition was 2.3 and 9.7 dS.m-1 respectively.The traits were Yield (Y), Chlorophyll content (CH), Number of Grain per Spike (NG), Number of fertile tillers (NT), Hundred Kernel Weight (KW), Biological Yield (BY), Peduncle Length (PL), Spike Length (SL), Plant Height (PH), Flag Leaf Length (FL), Number of Spikelet per Spike (NS), Awn Length (AL), Peduncle Weight (PL), Harvest Index (HI), Spike Weight (SW), Days to Heading (DH), Days to Physiological Maturity (DM), Grain Weight/Spike (GW), Fluorescence Maximum (FM), Variable Fluorescence (FV), Variable Fluorescence/ Variable Fluorescence (FV/FM), NA+, K+ and K+/NA+. Tolerance indices of stress tolerance index (STI) were calculated in this investigation for salinity. The Fluorescence chlorophyll and chlorophyll content was measured in the reproductive stage using a Chlorophyll Fluorimeter-PEA Plus and SPAD- CL-01 chlorophyll meter, Respectively. All biplots presented in this paper were generated by using the “GGEbiplot” and SAS9.01 software. Also, Person Correlation and Factor analysis carried out using by SAS9.01 and SPSS18 softwares.Results and discussion: This study demonstrated that GT biplot was an excellent tool for visual evaluation of superior lines, traits and grouping of them with other statistical techniques. The obtained data were analyzed using factor analysis and genotype trait (GT) biplot method based on site regression model.The biplot vector view indicate that there was a strong positive association between BY (Biological Yield) with seed yield in non-saline and CH (Chlorophyll content) with seed yield saline conditions. Factor analysis confirmed this results. It seems that CH and BY traits can be used as selection criterion for improving of seed yield in wheat breeding programs, especially under stress conditions in the field. Also, the three-dimensional diagrams derived from STI index and grain yield in non-stress and salt stress conditions confirmed that the number 1, 2 and 8 lines had the highest grain yield in non-stress and salinity conditions and were the most tolerant lines to salinity stress.Conclusions: the lack of identification of appropriate morphophysiological traits has been one major factor preventing improvement of yield in salinity environments, as well as the reason why plant breeders have not adopted more analytical approaches to selection. Moreover, any desirable morphophysiological trait should be simple, rapid and more economical than yield to assess. Generally, we conclude that tolerance to salt conditions in bread wheat lines seems to be related to its ability to production of Chlorophyll content. These findings will be useful in selection material for M6 breeding programs. Also, its was confirmed that the number 1, 2 and 8 lines had the highest grain yield in non-stress and salinity conditions and were the most tolerant lines to salinity stress

Introduction: The main limiting factor for food security in Iran and world is water qualitative and quantitative. Agriculture sector is the main consumer of water and more vulnerable section from water crisis. In order to improve food security calorie requirement of growing population should be provided from nonsaline water resources. Quinoa (Chenopodium quinoa) is diploeid, allotetraploied, C3 and facultative halophyte from Amaranthace family and categorized in pseudo cereal group. This plant has cultivated 5000 years in Ands, and the highest cultivated area is in Bolivia near salt flats. This plant can grow successfully in different countries such as, Europe countries, USA, Canada, Africa, Morocco, Pakistan and India. Protein content is between 13.81-21.9% and flour is gluten free and provides all essential amino acid of human. Because of high potential of quinoa for providing human calories and high salt and drought tolerance it could be considered for saline and marginal area. Quinoa was selected for cultivation with saline water because of salt tolerance and economic production with saline water which are not use for conventional crop. The main problem of quinoa is emergence and stand establishment with saline water. The aim of this study is evaluation of salinity stress on plant emergence and priming effect of emergence improvement under saline condition.Materials and methods: In order to evaluate salinity stress on emergence and establishment of quinoa an experiment was conducted based on CRD design with 5 levels of salinity (0, 4, 8, 12 and 16 dS/m) with four replication in soil and cocopit. Emergence recorded daily and finally plant height and dry weight was measured. Two piece and modified discount function model was fitted to emergence percent. In order to improve emergence under saline condition an experiment was conducted with three treatments (Gibberlic acid (10 ppm), H2O and Ascorbic acid (3 ppm)) and four levels of salinity (0, 4 and 8 dS/m) with three replications based on CRD design with factorial arrangement. Coefficent of equation was estimated with SAS software based on NLIN and REG procedure.Results and discussion: Result showed that quinoa is sensitive in emergence stage is depends to substrate and 50 % of emergence reduction in soil and cocopit occurred at 6.35 and 15.04 dS/m. Threshold in soil and cocopit was 9.52 and 0.03 dS/m. Emergence rate and percentage of seeds under saline condition in cocpit did not have significant differences up to 12 dS/m and salinity above 4 dS/m delay emergence. Seedling emergence index under nonsaline condition was 0.96 but at 4, 8 and 12 dS/m in soil had 24, 48 and 84 % reduction. Seedling height in soil and cocopit at 12 dS/m reduced 91 and 30 %, respectively. Priming could not improve quinoa emergence although hydroprime improve emergence to some extent (8%). Quinoa is sensitive to salinity at seedling stage but after this stage could produce 2-3 t ha-1 seed yield with 15 dS/m saline water in Yazd. Since, in saline area farmers don’t have fresh water and quinoa is sensitive to saline water during emergence and early establishment. It would be better use transplanting method or not coverage of seed with soil.

Introduction: Canola (Brassica napus L.) is one of the most important plants to produce edible oil in Iran and in the world and also one of the negative factors for crop plants is the relative salinity of irrigation water in some areas of Iran. According to the researchers, salinity incorporates high concentration of minerals that prevents plant growth. Effects of Salinity significantly in arid and semi-arid areas, areas with limited rainfall, high temperatures combined with high evaporation with high chemical fertilizers, and poor water and soil management, is observed and is an important crop production problem in these areas. Zeolites are a group of natural porous minerals that acts as a molecular sieve with its crystal structure practices and allow some passage of some ions and block the passage of some others, due to open channels in their ionic lattice. Due to zeolites high porosity and stems from its crystal structure, they can absorb up to 70% of bulk with water. Recent research on various applications of zeolites in crop plants as well as its effect on the process of how to prevent the entry of toxic ions such as sodium and absorption of essential nutrients has been concentrated crop and the interaction effect of the two substances necessary to appear on canola This experiment intends to determine the ways of control damage caused by 5 and 10 10 ds m-1 salinity on yield and yield components on four canola cultivars with application of 8 ton hec-1 zeolite.Materials and methods: The experiment was conducted as split plot factorial in randomized complete block design with three replication at the greenhouse research station of Agricultural Faculty of Tarbiat Modares University started in autumn 2013 and at the end of spring 2014 greenhouse operation was ended. Treatments were salt stress from beginning of flowering at three levels included control, 5 and 10 ds m-1, zeolite application with two levels included control and 8 ton hec-1 and varieties with foul levels Zarfam, Sarigol, Hayola and RGS. From 29 October 2013 (sowing) to 20 May 2014 (harvesting), Greenhouse environment was with normal light and temperature conditions. The soil of pots was sand mixed with field soil in ratio of 1: 1. Applied zeolite was clinoptilolite. To creation of appropriate drainage and prevent the accumulation of salt, three holes with one centimeter diameter was generated at the bottom of each pot. Salinity was started by adding salt mixture to irrigation water, before flowering. The final salt was mixed with salt water of Tehran, Gom and Kashan wells with ration of 2: 2: 4: 3: 4 and after standardization calculated with electrical conductivity meter and finally the salt water was transferred to each pot with graduated containers. On this experiment grain yield, yield components, yield and oil percentage and SPAD were measured. Mean comparisons were performed by LSD test using in SAS 9.2.Results and discussion: The results showed that the effect on all traits except harvest index was significant, and none of the treatments had no significant effect on oil percent Number of grain per pod, and salt stress did not affect harvest index and zeolite on grain yield, number of pods, number of grain per pod, harvest index and greenness significant effect. Results showed that application of zeolite increases grain yield 9 and 26 percentage in control and average stress levels of RGS. But in severe stress condition because of severe prevent water absorption by increasing the osmotic potential into the roots environment, had not significant effect on experimental varieties. Application of zeolite in control condition and non-application of zeolite in severe stress on Zarfam number of pod were the highest and lowest with the difference of 36 %, respectively. Sarigol in control condition and Zarfam in severe showed the highest and lowest of 1000 grain yield with the difference of 22 %, respectively and RGS in control condition and Hayola in severe showed the highest and lowest of number of grain in pod with the difference of 54 %, respectively. It was also observed that application of zeolite in control stress condition on RGS and non-application of zeolite on Hayola in severe stress condition showed the highest and lowest of dry weight with the difference of 50 %, respectively. Results showed that, Sarigol in control condition of salt stress and zeolite was the highest of oil yield compared to Zarfam in condition of severe stress and non-application of zeolite with 66 percentage. Results of the experiment was shown, Zarfam in average stress and non-application of zeolite showed the highest amount of SPAD compaire to the same variety in severe stress and non-application of zeolite with more than double.Conclusions: Application of Zeolite increases grain yield of Zarfam and all three levels of salinity reduces this trait in canola varieties, significantly. Due to the low price (500 rials per kg) of zeolite and abundance of this mineral in our country, it can be used to prevent performance degradation of the material used in high salinity lands. Sarigol showed higher values of SPAD index than other cultivars, in terms of salinity and application of zeolite prevent the reduction of SPAD index values in terms of stress.

Introduction: Soil salinity is one of the major abiotic stresses affecting plant growth and production. It is estimated that approximately half of the irrigated lands of Iran are affected by salinity and much of the agricultural lands of Iran especially in the central regions are susceptible to salinity. According to the development of saline soils and water resources, utilization of halophytes as alternatives for cultivation in saline conditions could be a suitable strategy to crop production. In addition to understanding the physiological salinity tolerance pathways, studying such crops could help to plant breeding and transferring these useful traits to crop species and also domestication of these plants.Materials and methods: This experiment was conducted in 2009-2010 in Salinity Research Station of faculty of agriculture, Ferdowsi University of Mashhad as split-plot based on Complete Randomized Block Design with three replications. Salinity as the main plot had two levels of 5.2 and 16.5 dSm-1 and five kochia ecotypes including Birjand, Urmia, Borujerd, Esfahan and Sabzevar were allocated as sub-plot. Seedlings were irrigated with saline water having electrical conductivity (EC) of 5.2 dSm-1 until the full establishment and thereafter salinity stress was imposed with saline water having EC=16.5 dSm-1. Physiological and biochemical traits were measured in the youngest fully expanded leaf at the beginning of the anthesis and shoot biomass at the end of the growth season. Data analysis was performed using Minitab 16 and means were compared by LSD test at a significance level of 0.05.Results and Discussion: Results indicated that biomass was increased in Birjand, Isfahan and Urmia ecotypes as salinity level increased while it was decreased in Sabzevar and Boroujerd ecotypes. A reduction of 34, 31, 11 and 29 percentage and an increase of 4 percentage in seed yield was seen in Sabzevar, Birjand, Boroujerd, Urmia and Isfahan, respectively. Harvest index was also increased in Isfahan while it was decreased in the other ecotypes with the highest reduction in Birjand ecotype. An increasing trend of shoot Na+content at anthesis was observed in all ecotypes showing the highest increase in Boroujerd and Isfahan and the lowest in Birjand ecotypes. A lower shoot K+content at anthesis was observed in all ecotypes except Urmia in higher salinity levels. In contrast to Sabzevar soluble carbohydrates was decreased in Urmia, Isfahan, Boroujerd and Birjand in higher salinity levels. Increasing salinity intensity caused an increase in leaf proline content in Birjand and Isfahan ecotypes while it had no effect on Boroujerd and an additive effect on this parameter in Urmia and Sabzevar ecotypes. A higher osmotic potential was found in Boroujerd, Birjand and Sabzevar in higher EC levels. Phenol content was lower in Urmia, Boroujerd and Birjand in higher salinity levels while it was higher in Sabzevar. No significant difference was observed in Isfahan ecotype according to this parameter. DPPH radical scavenging activity was decreased in Birjand, Urmia and Boroujerd while it was increased in the other two ecotypes.Conclusion: Regarding higher biomass and lower physiological indices such as soluble carbyhydrates, total phenol, DPPH radical scavenging activities in Birjand and Urmia ecotypes, it may be cocluded that higher amounts of these parameters might not be suitable traits in salinity tolerant genotypes selection.

Introduction: Salinity stress is one of the main environmental stress limiting growth, development and economical yield of plants in different areas of the world, especially in the countries which are located in the arid and semi-arid regions. The extent of damage to the plant and reduction in yield heavily depends on the level of salinity in soil or irrigation water. Reducing growth and morphological development at the initial stages of the stress and accelerate tissue senescence at later stages will result in reduced agricultural productivity. Plant species and cultivars vary in their tolerance to salinity and ability to maintain physiological functions and yield production under stress. Increasing the concentration of salts in the soil solution usually leads to osmotic stress, specific ion toxicity and ionic imbalances and consequently decreases in plant growth. Peppermint (Mentha piperita L.) is one of the most important medicinal plants and its essential oils are widely used in pharmaceutical, food, cosmetics and hygienic products. This plant is a popular herb that can be used in different forms such as oil, dried powder and leaf extract. Peppermint is comprised of a high amount of natural essential oils, as well as menthol and Menthone. It is known for its refreshing, cooling, bactericidal and anti-irritant properties. The concentrations of various secondary metabolites in different plant species are strongly depended on the growth conditions, especially stress conditions. Although the negative effect of salinity stress on essential oil yield is well documented but the effects of salinity stress on chemical composition of essential oil is not predictable and constant. Therefore in the present study, we have evaluated the effects of the different levels of salinity stress (0, 2, 4 and 6 dS/m) on morpho-physiological traits and also essential oil components of Peppermint.Materials and methods: In order to evaluate the effects of salinity stress on morpho-physiological parameters and essential oil of peppermint an experiment was conducted based on completely randomized design with five replications and four treatments. The treatments were included different levels of salinity (i.e.0, 2, 4 and 6 dS/m). Studied traits were relative water content, leaf area, the photosynthetic pigments and dry weight (root, shoot and leaf). Essential oil component were determined with gas chromatography-mass spectrometry (GC-MS). Analysis of variance (ANOVA) was done by SAS 9.4 software and mean comparisons were done by Duncan’s multiple range test (DMRT) at 1% probability.Results: According to the results, different levels of salinity stress had significant effects on the studied traits at a level of 1% probability. The highest amount of the relative water content (67.6%), plant leaf area (1609 mm), root dry weight (12.4 g), shoot dry weight (17.1 g), leaf dry weight (17.4 g), Chlorophyll a (2.84 mg/g FW), Chlorophyll b (1.62 mg/g FW), total Chlorophyll (4.46 mg/g FW), carotenoid (1.04 mg/g FW) and essential oil (0.23%) were obtained from control while the lowest amount of the relative water content (59.1), leaf area (1076 mm), root dry weight (7.34 g), shoot dry weight (8.72 g), leaf dry weight (9.18 g), Chlorophyll a (1.82 mg/g FW), Chlorophyll b (0.94 mg/g FW), total Chlorophyll (2.77 mg/g FW), carotenoid (0.74 mg/g FW) and essential oil (0.13%) were obtained from 6 ds/m2. The results showed that with increasing salinity stress, the concentration of most of the essential oil components such as Menthol, D-Limonen, α-pinene, Sabinene, Menthofuran, 1, 8-Cineole were reduced but Menthone was an exception where its content increased under salinity stress.Conclusion: Increasing the salinity stress significantly impressed all of the studied morpho-physiological traits in Peppermint and reduced them. Although most of the essential oil components were decreased under salinity stress but some components of essential oil such as Menthon were increased under salinity stress conditions. Reducing biological yield and also essential oil content will cause significant decrease of essential oil yield per unite area.

Introduction: Water and soil salinity are the most fundamental agricultural problems in arid and semi-arid area. There are some microorganisms in soil that helps plants in nutrients absorption in many ways. Mycorrhizal fungi are capable of establishing symbiosis with the roots of most plants. This symbiosis has several advantages for the host plants, including increased tolerance to environmental stresses and diseases. Pseudomonas is one of the main Mineral phosphate-solubilizing bacteria, due to the wide range of stimulating plant growth traits are improved plant growth. Isabgol (Plantago ovata Forsk.) is a plant from (Plantaginaceae) family. Currently, production of this plant is one of the 15 species medicinal plant that have economic priority. To find out the effect of arbuscular mycorrhizal fungi, Mineral phosphate-solubilizing bacteria in salinity condition on yield and yield components Isabgol (Plantago ovata Forsk.), this experiment designed and implemented.Materials and Methods: The field experiment was conducted at the research farm of national salinity research center in Hosein Abad, Yazd in 2015. A split-factorial experiment based on randomized complete block with three replications. Three levels of salinity 2.5 (control), 5 and 10 dS.m-1 was as the main plot and mycorrhizal fungi and PSB were as sub plots. Arbuscular mycorrhizal fungi include two levels (Glomus intraradices and control) and PSB also includes two levels (Pseudomonas fluorescens bacteria control). After field preparation planting with 100 plants per square meter and 30 cm rows, was taken. Weed control was with hand weeding and herbicide was not used. Salinity stress started at 3-4 leaf stage with water mixture of different salinity level wells. To ensure the same level of irrigation in salinity factor, irrigation was done in a controlled manner. To determine the yield components, five plants of each plot were harvested and plots harvested at end to determine yield traits. Statistical analysis was performed with SAS software. Comparison of mean also was conducted by protected LSD test at five percent probability level.Results and discussion: Analysis of variance showed salinity had a significant effect at 5% level on tillers numbers per plant and significant effect at 1% level on spike numbers per plant, seeds numbers per spike, 1000 seed weight, harvest index, biological yield and seed yield. The effect of arbuscular mycorrhizal fungi and Mineral phosphate-solubilizing bacteria on spike numbers per plant, seeds numbers per spike, 1000 seed weight, biological yield and seed yield was significant at 1% level and the effect of PSB on tiller numbers per plant and harvest index was significant at the 5% level. Also salinity, AMF and PBS interaction was significant at 5% level on biological and seed yield. Comparison of means showed that the highest spike numbers per plant, seeds numbers per spike, 1000 seed weight, harvest index, biological yield, seed yield, were 18.3 number, 43.4 number, 1.5 gr, 27.9 %, 3805 and 1063 kg.h-1 at 2.5 dS.m-1 salinity and the minimum number of these traits were 12.4 number, 31.2 number, 1.35 grams, 22.3%, 2164 and 485 kg.h-1 at 10 dS.m-1 salinity respectively. Also interaction results showed that maximum biological and seed yield was 4539 and 1310 kg.h-1 at 2.5 dS.m-1 salinity, Glomus intraradices and Pseudomonas fluorescens and minimum biological and seed yield was 1817 and 368 kg.h-1 at 10 dS.m-1, non inoculated and no bacteria respectively.Conclusions: Totally the results of this study showed that water salinity can have a negative effect on yield of Isabgol, but utilizing of some soil microorganisms can compensate these negative effects. Therefore, utilizing bio-fertilizers can improve water and nutrients availability, moreover increase yield traits and effective in safe medicinal plant production.

Introduction: Salinity is one of the most important factors reducing the yield of many crops. The usual response of plants to increasing concentrations of salt at the root zone is osmotic stress, ionic toxicity and nutrient deficiencies. Also, cadmium is one of the major heavy metal pollutants by high toxicity and accumulation, caused retard in the plant growth. The problem of Cd toxicity becomes even more severe when plants are exposed to salinity. The different materials are considered to mitigate the negative effects of stress on plants. In this regard, the selenium introduced as one of the trace elements beneficial to plants so that it can protect plants against adverse effects of stress. The purpose of this study was to determine uptake of cadmium, sodium, potassium and developmental and physiological changes of garlic seedlings exposed to cadmium under salt stress in the presence of selenium.Materials and methods: A factorial experiment in based on a completely randomized design with three replications was done in Crop Physiology Laboratory, Faculty of Agriculture, Bu Ali-Sina University. Cadmium as cadmium chloride in 0, 10-4, 10-3 and 10-2 M concentrations and sodium chloride at two levels (0 and 25 mM) and sodium selenate (0 and 5 mg/ l, Na2Se2O4) were added to the growth medium. The traits growth of root and shoot dry weight was measured. In order to determine the content of cadmium, sodium and potassium, 0.2 g of tissue dry matter ground and by the wet digestion method and atomic absorption spectrophotometer (Varian, 220) was read content elements. The amount of chlorophyll in the shoot was calculated using Arnon method. Parameters of net photosynthesis, stomatal conductance and transpiration were measured in a fully open mature leaf by using an infrared analyzer. Data analysis was performed using SAS software and mean comparisons test data was used by least significant difference (LSD) and LSMEANS.Results and discussion: The results showed that salinity and cadmium have caused a significant reduction in root and shoot dry weight, total chlorophyll content, net photosynthesis, stomatal conductance and transpiration. Interaction between salinity and Cd at 10-4 M decreased the absorption of Cd in seedling and followed by more improving chlorophyll content, net photosynthetic as a result from root and shoot dry weight increased compared to non-saline condition. But this effect was not observed at 10-3 and 10-2M Cd concentrations. On the other hand, selenium alone or in the presence of salinity or cadmium caused a significant increase in above mentioned growth traits. Also, salinity and cadmium raised sodium to potassium ratio in the shoot. The interaction of between salinity and cadmium with increasing concentration of Cd, sodium to potassium ratio enhanced in the aerial parts of the plant.Conclusions: Overall, salinity and cadmium stresses in garlic seedling media, reduced root and shoot dry weight, chlorophyll, photosynthesis, transpiration and stomatal conductance. Application of selenium alone and also in present salinity and cadmium caused a significant increase in root and shoot dry weight, chlorophyll, net photosynthesis, transpiration and stomatal conductance. Although low concentrations of salinity and cadmium (10-4M) revealed a significant increase in root and shoot dry weight, which implies an increase in chlorophyll content and photosynthesis in plant garlic. Selenium also improved the total chlorophyll, photosynthesis in the interaction between salinity and cadmium. This subject confirms the positive effect of selenium on garlic seedling growth under cadmium and salt stresses, which in subsequent studies the physiological and molecular processes should be further investigated.

Introduction: Iron is an essential micronutrient for plant growth that plays an important role in plant metabolism. Iron deficiency is an abiotic stress that is often found in plants grown in calcareous and alkaline soils. The solubility of Fe+3 decreases dramatically with increasing pH.30% of the arable land worldwide consists of calcareous and alkaline soils. Common iron fertilizers used to reduce deficiency syndromes contain iron (II) sulfate heptahydrate (FeSO4.7H2O) or iron chelates. Iron chelate (for example Fe-EDTA) is absorbed by plants, which however depends on soil conditions especially soil pH. Nowadays, nano-Fe fertilizer can be used as a rich source of iron for plants, because it gradually releases Fe in a wide pH range (pH 3– 11). Nanofertilizer usage leads to increase element efficiency, reduce soil toxicity and negative effects caused by the excessive consumption of chemical fertilizers and reduce the fertilizer’ s application. This research was carried out to determine the suitable type of iron fertilizer and to evaluate the effects of different concentrations of nano-Fe fertilizer on Medicago sativa.Materials and methods: In order to investigate the effects of Fe-deficiency and different levels of Fe2O3 nanoparticles compared to Fe-EDTA on leaf growth, photosynthetic pigments and antioxidative activity of alfalfa (Medicago sativa cv.Hamadani), an experiment was conducted based on completely randomized design with three replications in Arak University during 2015. After germination of sterilized seeds of alfalfa, 1-day seedlings were cultured in plastic vases contains perlite. Plants were maintained under 25/18°C day/night temperatures with 12-hr photoperiod. Irrigation was done weekly with 100ml complete Hoagland solution (containing iron chelate (Fe-EDTA) for control plants) or 100ml Hoagland solution without iron chelate and containing different concentrations of ironoxide nanoparticles (0, 5, 10, 20 and 25mM). Plants treated with 0 µM iron nanoparticles did not receive iron in 45day period. Ironoxide nanoparticles were prepared from Pishgaman Company located in Mashhad, Iran. After the final harvest of 45-day plants, leaf fresh weights were measured. Dry weight of leaf were obtained by drying samples in an oven for 24h at 75°C until constant weight. Chlorophyll a, chlorophyll b, total chlorophyll and carotenoids contents by spectrophotometry method at 663 and 645 nm were determined. Contents of proline, activities of catalase (CAT), guaiacol peroxidase (GPOX) and superoxide dismutase (SOD) and 2, 2diphenyl-1-picrylhydrazyl (DPPH) scavenging activity were measured. All data were analyzed by variance analysis using SPSS16. Mean comparisons were conducted using Duncan’s test.Results and discussion: Iron treatment had a positive effect on the growth parameters and photosynthetic pigments. The highest and lowest values of leaf growth and photosynthetic pigments were obtained at 25μM and 0µM of Fe2O3 nanoparticles, respectively. Treatment of iron nanofertilizer at different concentrations (even at 5µM) caused significant increase in leaf growth and photosynthetic pigments content compared to iron chelate. Nanoparticles have high reactivity because of more specific surface area, more density of reactive areas, or in creased reactivity of these areas on the particle surfaces. These features streamline the absorption of fertilizers, which are produced in nano scale. Iron nanofertilizer can be considered as an enriched source of bivalent iron for plant because of its high stability and gradual release of Fe in a wide pH range (pH 3–11). Iron is a necessary element for the formation of chlorophyll, therefore deficiency of iron in plants reduces chlorophyll content, so photosynthesis decreases The highest values of proline and antioxidants activity were measured in 0μM ironoxide nanoparticles. Thus, iron concentration of 0mM is considered stressful for alfalfa. Under abiotic stresses, reactive oxygen species (ROS) content increases more than the normal condition. ROS are highly reactive and toxic and damages cell membranes. Therefore, the concentration of ROS in cell must be controlled. In such conditions, plants develop a high efficient antioxidant defense system to increase tolerance to different stress factors. Overexpression of ROS scavenging enzymes like SOD, CAT, and GPOX resulted in abiotic stress tolerance in various crop plants due to efficient ROS scavenging capacity. It has been reported that proline act as an osmolyte, a metal chelator, ROS scavenger/an antioxidative, membrane stabilizer, and a signaling molecule Thus, the proline content is a good marker for screening tolerant varieties under stress conditionIn this study, There was no statistical difference between different levels of Fe2O3 nanoparticles and Fe-EDTA based on values of proline and antioxidants activity, because stress conditions are not created in levels of Fe2O3 nanoparticles and Fe-EDTA.Conclusions: Therefore, the suitable type of iron-fertilizer for alfalfa is iron nano-fertilizer and the concentration of 25μM Fe2O3nanoparticles is the optimum value.

Introduction: Some seeds will enter thermoinhibition when imbibed at warm temperature regimes. Seed thermo inhibition is the situation when germination of seeds that have been imbibed at warm temperature is prevented, but the seeds will subsequently germinate rapidly when the temperature is reduced. It is therefore a temporary inhibition of germination that can be alleviated simply by lowering the temperature. This process generally occurs at temperatures considerably lower than ceiling temperature. It may also occur over a small range of temperatures, such that germination can go from 100 to 0 % when the upper temperature limit is exceeded by only a few degrees. This germination behavior is often associated with a winter annual life cycle common in Mediterranean-type climates with wet winters and dry summers, as seeds that are shed in early summer and have subsequently after-ripened nonetheless may not germinate when hydrated at warm temperatures, waiting instead until the fall for cooler temperatures and more certain rainfall before germinating. Patterns of seed germination behavior of different populations in response to warm temperatures can be described using the models based on thermal-time units. In this study, thermal-germination model was developed based on four different probability distribution functions of Normal, Lognormal, Gumbel and Weibull. Seed thermo inhibition in six cultivars of spring oilseed rape (Brassica napus L.) were then quantified using these models.Materials and methods: Experiment was conducted at the Seed Technology Laboratory, Ramin Agriculture and Natural Resources University, Khuzestan. In this study, germination responses of six spring oilseed rape cultivars (Sarigol, RGS003, Dalgan, Hyola-401, Jerry and Julius) were investigated at constant temperatures. Germination test were conducted in the dark at eleven constant temperature regimes of 8, 12, 16, 20, 24, 28, 32, 33, 34, 35 and 36oC with a range of ±0.2oC. For each cultivar, germination test was carried out in a completely randomized design with four replications and the entire experiment was repeated three times. The germinated seeds (criterion, radicle protrusion of>2 mm) were counted and removed at specified intervals. Seeds of all cultivars germinated more rapidly at 32 ºC than at higher or lower temperature regimes. Therefore, the optimum temperature for germination was assumed to be 32 ºC. Above this, oilseed rape seeds showed thermo inhibition of germination. So that, ungerminated seeds of each cultivar at these warm temperature regimes were germinated rapidly at low temperature of 20oC. Cumulative-germination curves of oilseed rape cultivars in temperatures beyond 32 ºC were used to perform non-linear regression procedures to assess the relative accuracy of different thermal-germination models in predicting germination response under constant temperatures. The thermal-germination models were fitted to the germination data of each cultivar using the PROC NLMIXED procedure of SAS. Assessment of goodness-of-fit was performed by the Akaike information criterion (AIC).Results and discussion: Assess the goodness of fit indicated that precision of the thermal-germination models was different in describing the germination behavior of early- and mid-maturing cultivars of oilseed rape. Thermal-germination model based on Normal distribution provide the best fit to data of germination progress over time for early-maturing cvs. Dalgan (AIC=-237.5) and Hyola-401 (AIC=-168.8). For mid-maturing oilseed rape cultivars (Sarigol, RGS003, Jerry and Julius), the smallest AIC values were obtained for the Gumbel thermal-germination model, while the model based on Normal distribution gave the worst fit to germination data. The germination responses of early- and mid-maturing oilseed rape cultivars to supra-optimal temperature regimes were different. Early-maturing cultivars showed 5, 50 and 95% thermo inhibition of germination at averaged temperatures of 33.52, 33.99 and 34.37 ºC, respectively. While, seed thermo inhibition in mid-maturing cultivars reached to 5, 50 and 95 % of maximum at averaged temperatures of 33.63, 34.34 and 35.59 ºC, respectively. Based on the model prediction, the germination completely inhibited at an average temperature of 34.54 ºC in early-maturing cultivars and an average temperature of 36.64 ºC in mid-maturing cultivars. Abscisic Acid (ABA) has been reported as the major regulator of seed thermo inhibition.Conclusions: Early-maturing oilseed rape cultivars have lower thermal-thresholds compared to mid-maturing cultivars. A different thermal-germination model was necessary for predicting the probability of seed germination in response to warm temperature regimes depending on the type of germination behavior of early- and mid-maturing cultivars. Thermal-germination models proposed here well described the observed thermo inhibition response of seed germination in oilseed rape cultivars.