طول ریشه چه

Weeds are one of the most important problems in agriculture and cause a lot of damage to crops. Overconsumption of herbicides in recent decades has led to harmful impacts on the environment and living organisms, including humans. In order to deal with these problems today, efforts are being made to reduce reliance on artificial herbicides and change direction towards sustainable agriculture as a part of integrated weed management. Among natural compounds, essential oils, which are components of aromatic and medicinal plants, were investigated to discover new herbicides.

In order to investigate the effects of yarrow essential oil (Achillea wilhelmsii C. Koch) on the germination and growth of purslane (Portulaca oleracea L.) and rye (Secale cereale L.) seedlings, two factorial experiments were conducted in the form of a completely randomized design in three replicates at Islamic Azad University, Science and Research Branch. The first factor was the type of essential oil in two levels (normal and nanoemulsion) and the second factor was the concentration of essential oil in six levels (0, 100, 200, 400, 800, and 1000 µl L-1).

Scanning electron microscopy images showed the particles were relatively sperhical and their size varied from 1 to 100 nm. The zeta potential of the nanoparticles was -13.8 mV, indicating particle stability. Both type of essential oils reduced germination percentage, germination rate, plumule length, radicel length and seedling dry weight of both weeds and germination percentage decreased significantly with increasing concentration. At a concentration of 200 µl L-1, purslane treated with essential oil germinated 55.25%, but at the same concentration, the germination percentage of seeds treated with nanoemulsion of essential oil was 30.50%. Nanoemulsion of essential oil at concentration of 800 µl L-1 was able to completely prevent the germination and growth of purslane seedlings. Nanoemulsion of essential oil at a concentration of 1000 µl L-1 completely prevented rye seed germination. Germination rate decreased under treatment of yarrow essential oil and there was no difference between two types of essential oils at concentration of 200 µl L-1, but at a concentration of 800 µl, the germination rate of rye seeds treated with nanoemulsion of essential oil and ordinary essential oil reached to 1.40 and 0.32, respectively which was a significant difference.

The inhibition percentage of the studied traits in both weed species showed that the essential oil nanoemulsion was more effective than the normal essential oil. Yarrow essential oil was more effective on purslane weed compared to rye. Essential oils do not have similar effects on weeds and their inhibitory effects will be different depending on the concentration and species of weeds, and the selectivity of these compounds should be investigated. The production of nano essential oil of yarrow as a natural herbicide is a solution. It offers to control weeds in organic farming systems.

Highlights:

1- Nanoemulsion particles were produced from Yarrow essential oil
 2- Nanoemulsion particles had more inhibitory effects on the investigated weeds than the normal essential oil.

 Lallemantia royleana is an annual herbaceous plant of Lamiaceae family in different parts of Europe, the Middle East, and especially Iran. Cyamopsis tetragonoloba L. is a plant of the legume family. A common feature between these two plants is hydrocolloid gums, which stabilize some food emulsions by absorbing water and increasing the viscosity or forming a gel in the aqueous phase. Due to its diverse and rich vegetation, Iran can produce countless types of plant gums, and many seeds such as Lallemantia royleana and Cyamopsis tetragonoloba contain valuable gums. Considering the important therapeutic and industrial applications of C. tetragonoloba and L. royleanaplants and the need for more information and reports on determining the best humic acid level and salt stress tolerance of these plants, the purpose of this research is to investigate the tolerance of two L.  royleana and C. tetragonoloba plants to salinity stress in the germination stage and the initial stages of the growth of two plants under the humic acid application.

The experiment was carried out as factorial in a completely randomized design with three replications at the seed laboratory of the Faculty of Agriculture of Zabol University in 1400. In this experiment, salinity stress was investigated using sodium chloride at control (no salinity), 70, 140, 210 mM levels and humic acid at (0, 40, 80, and 120 mg/L) levels. Humic acid solution at different salinity levels was added to each petri dish containing 25 seeds.

 The results showed that salinity stress decreased germination percentage, radicle length, plumule length, seedling length and seedling dry weight of C. tetragonoloba. In this plant, the germination percentage decreased by 35.34% compared to the control as the salinity stress level increased to 210 mM, and with the increase of the stress to more than 140 mM, a significant decrease in the germination percentage was observed. The maximum plumule length of L. royleanaplants was obtained in 70 mM salinity treatment and 40 mg/L fertilizer level. The maximum radicle length in the L.  royleanaplants plant was obtained in the treatment of 40 mg/L of humic acid at a 70 mM salinity stress level. Also, the results showed that the maximum radicle length (1.46 cm) in the C.  tetragonoloba plant was related to humic acid pretreatment at 70 and 140 mM salinity and fertilizer levels of 40 and 80 mg/L.

 In general, it can be stated that the germination indices significantly decreased under stress conditions, and this indicates that humic acid is a suitable pretreatment that can improve the growth indices of C. tetragonoloba and L.  royleanaplants under stressed and non-stressed conditions. With the application of humic acid at all salinity levels except 210 mM, the germination indices in the two mentioned plants were in a favorable condition.

1- The salinity stress tolerance threshold was studied in Cyamopsis tetragonoloba and Lallemantia plants.
2- Humic acid fertilizer in this study mitigated the destructive effects of salinity stress in Cyamopsis tetragonoloba and Lallemantia plants.

In order to investigate allelopathic effects of aqueous licorice leaf and root extract on germination properties and some enzymes activity of wheat and chickpea seedlings, a factorial experiment based on completely randomized design with 3 replications was conducted out in Shahid Bahonar University of Kerman laboratory in 2017. Treatments were leaf and root extracts of licorice (25%, 50%, 75% w/v) and distilled water as a control. Increasing leaf extracts concentration caused the greatest reduction in germination percentage and rate (97.2% and 97.3%) of wheat, and root and stem length (92.2% and 67.8%) of chickpea. Meanwhile, increasing root extracts concentration caused the greatest reduction in germination percentage and rate (56.6% and 74.8%) of wheat, and root and stem length (93.6% and 66.7%) in chickpea. Although the malondialdehyde concentrations of wheat and chickpea seedlings were significantly increased (66.3% and 24.2% in wheat and chickpea affected with leaf extract, and 63.1% and 15.8% in wheat and chickpea affected with root extract, respectively), wheat seedling showed higher sensitivity. Catalase activity showed significant decrease in treatments (91% and 46% in wheat and chickpea affected with leaf extract, and 95% and 54% in wheat and chickpea affected with root extract, respectively). This enzyme activity showed more decline in wheat than chickpea. These results also indicated that the leaves aqueous extract has more allelopathic inhibitory effects than the roots.

In order to investigate the composition and herbicidal activity of yarrow essential oil on barnyard grass (Echinochloa crus-galli (l.) beauv) and common lambsquarter (Chenopodium album L.), two factorial experiments were conducted in a complete randomized design with four replications at Islamic Azad University in 1399. The first factor was the type of essential oil at two levels (ordinary and nano) and the second factor was the concentration at six levels (0, 100, 200, 400, 800 and 1000 µlL-1). The results of essential oil analysis led to the identification of 49 compounds. Among these compounds, camphor (21.1%), 1,8-cineole (19.3%), myrtenol (8.4%), carvacrol (8.3%) and borneol (6.1%) are the main compounds in essential oil. Scanning Electron Microscopy Images showed the particles were 1 and 100 nm in size. There was no significant difference between the concentrations of 100 µlL-1 of the two types of essential oils in germination percentage of barnyard grass. However, with increasing the concentration, this difference became significant, so that at a concentration of 400 µlL-1, the germination percentage of barnyard grass treated with ordinary and nano essential oils reached 30.12 and 10.02%, respectively. Germination completely inhibited with nano essential oil at 1000 at µlL-1 concentration in barnyard seeds. At a concentration of 400 µlL-1 of nano and ordinary essential oils, common lambsquarter germinated at 36.12 and 13.02 percent and nano essential oil at a concentration of 800 µlL-1 completely prevented germination. Common lambsquarter was more sensitive to essential oil of yarrow in comparison with barnyard grass.

Fitness costs of herbicide resistance may be more evident and increase under stress environmental conditions. To test this hypothesis, a herbicide-resistant (R) and a herbicide-susceptible (S) phenotype with controlled and homogenized genetic background were isolated within a non–target-site resistant (NTSR) black-grass population. Accumulated maximum germination (Gmax) and time to reach the Gmax (G50) of biotypes were examined under non- and abiotic-stress conditions (salinity at 16 dSm-1, drought at -0.8 Mpa). In addition, seedling pre-emergence growth of the biotypes were evaluated at non-stress condition. There was no difference in Gmax between the R and S biotypes, whereas the Gmax of R phenotype was 28% and 49% lower than that of the S phenotype under salinity- and drought-stress conditions, respectively. The R phenotype germinated around seven to 16 hours later than the S phenotype under all non- and abiotic-stress conditions, i.e. the R phenotype had higher G50 than the other phenotype. The experiments of seedling pre-emergence growth showed that the R and S biotypes had similar root and shoot length under non-stress condition. The results clearly showed that the germinability fitness costs of NTSR black-grass increase when the plants are grown under salinity- and drought- stress conditions.

Nowadays, in response to the consequences of herbicide application and gradual reduction of farm crops, suitable biological methods have been identified to control the weeds.In this respect allelopathic can be show useful potential for biological to control of weeds.Soin order to evaluate the allelopathic effects of saffron (Crocus sativus L.) corm and leave aqueous concentrations on germination characteristics and preliminary growth of tow weed species including rye (Secale cereale L.) and oat (Avena ludoviciana L.), A factorial experiment was conducted based on a completely randomized design with three replications at Seed Science laboratory of faculty of agriculture in University of Birjand during 2015.Treatments included saffron organs at 2 levels (leaves and corms) and water extract concentrations at 5 levels (0, 0.5, 1, 1.5 and 2 percent). Studied traits were germination percentage, rate of germination, radicle length, root fresh weight, root dry weight and mean germination time.Results showed that the organs and aqueous concentrations of saffron had significant effects on all evaluated traits in two weeds.The lowest seed germination percentage of rye and oat were observed at 2% concentrations of corm and leaves extracts (up to74/6% and 66/6% reduction compared to control, respectively). Also the rate of germination of oat decreased (up to 50% compared to control) with 2% concentration of extract but the rate of germination on rye was not significantly affected by extract concentrations. Based on orthogonal comparison tests, the allelopathic inhibition effects was more of saffron leaves on rye and oat.

Allelopathy refers to the interaction of plants with their released chemicals on each other. Allelopathic compounds play an important role in biodiversity and the ability to produce ecosystems.In order to investigate the effects of allelopathy on Rosa damascena Mill on germination of wheat (Triticum aestivum L.) seeds. The experiment was done as factorial based on completely randomized design with three replications. The distilled water treatments used as control and different concentrations (0, 1, 2, 3, 4 and 5%) of aqueous extract of dried Rosa flowers used as treatments. Rosa flowers were from Boukan and Khansar, the designwere completely randomized in three replications. The results of this experiment showed that the juice extract with the mentioned concentrations did not reduce germination as compared to the control.The aqueous extract of Boukan showed a significant decrease in plumulelength, radiclelength, plumuledry weight, radicledry weight, and soluble protein content in wheat. Also, the extract of Khansar showed the highest inhibitory effect on plumule fresh weight, radicle fresh weight and soluble sugar content on the wheat plant.The analysis of variance showed that the difference between the extracts, treatments and extract × treatment was significant (P <0.05). There was a significant correlation (P <0.05) between fresh weight, dry weightand length, as well as protein and sugar content in both plants.

Salinity is an environmental factor that affects all stages of plant development from germination to fruit and grain production more or less. Germination is one of the most critical stages in plant growth under salt stress conditions. In order to investigate the effect of salicylic acid on germination and growth characteristics of Fenugreek seedlings seedlings under salinity stress, an experiment was carried out in a factorial experiment in a completely randomized design with three replications in 2017 in Agriculture and Technology Laboratory, University of Mohaghegh Ardebili. Experimental factors included concentrations (0, 0.5 and 1 mM) of salicylic acid and salinity levels including zero (control), 50, 100 and 200 mM sodium chloride. The results showed that with increasing salinity percent and germination rate, seedling length, seedling dry weight and Fenugreek weight decreased. Germination percentage (50%), germination speed (35%), seedling length (40%) and seedling dry weight (45%) were obtained at 200 μm salinity (without salinity). Application of 1 mM salicylic acid could significantly improve the traits compared to the control. The results of this study showed that the use of salicylic acid could greatly endure fungal strain under stress conditions.

Extended abstract Quinoa, with the scientific name (Chenopodium quinoa Willd), belongs to the Spencer family. Seeds vigor can be improved with a variety of seed priming methods. In this method, the seeds are soaked in water or various osmotic solutions and then dried to the original moisture. After priming treatment, seeds are stored and cultivated as untreated seeds. Potassium nitrate is the most frequently used chemical for the purpose of increasing seed germination and is recommended by the Society of Official Seed Specialists and the International Association of Seed Testing for germination experiments of many species. In recent years, the use of nanoscale materials has been of great interest to researchers. Chitin, one of the most abundant polysaccharides in nature, is a polymer chain of N-acetyl glucosamine and is associated with other proteins and other organic compounds, and numerous industrial, pharmaceutical and agricultural applications have been reported for it. The present study was carried out to investigate the effects of chitosan nanoparticles and potassium nitrate on some morphological characteristics, germination characteristics, chlorophyll content and relative humidity of quinoa plant. In order to investigate the effect of pretreatment of quinoa seeds with chitosan nanoparticles and potassium nitrate solution on the early stages of germination, a factorial experiment was conducted in a completely randomized design with four replications in Seed Processing Laboratory, Faculty of Agricultural Sciences and Natural Resources, Shahed University, Tehran, Iran. Experimental treatments consisted of priming with chitosan nanoparticles in 4 levels (no primers, 0.01, 0.20 and 0.04% w / v) and potassium nitrate in 3 levels (no primers, 0.2 and 0.5% Weight percent) and hydroperime for 2 hours at 25° C. For each replicate of every treatment 100 seeds, using standard priming methods, were treated with the materials mentioned above and were dried in a petri dish on Watman paper No. 1 at 20 ± 1 ° C and relative humidity of 70% and 16 hours of daylight and 8 hours of darkness to make germination work. After that, germination percentage, root length, shoot length, germination coefficient, Allometric coefficient, relative water content, chlorophyll content a and b were measured, using standard methods. Seed treatment with 0.2% potassium nitrate solution increased germination by 9% and treatment with chitosan 0.01% increased germination by 14%, compared with the non-primer treatment. The priming treatment with a 0.5% solution of potassium nitrate and 0.01% chitosan increased germination by 36%, compared to the non-primer treatment. Potassium nitrate increased root length by 25% and shoot length by 10%. In addition, chitosan 0.01% increased the root length by 6%, and seeds with chitosan 0.02% and potassium nitrate 0.2% increased the root length by 32%. The effects of potassium nitrate, chitosan and their interaction on chlorophyll a and b were significant at 1% probability level. The highest levels of chlorophyll a were obtained in 0.02% chitosan and 0.2% potassium nitrate. This formulation increased the chlorophyll a content by 33%. The highest amount of chlorophyll b was obtained by applying 0.01% chitosan and 0.5% potassium nitrate. The results of this study showed that treatment with 0.01% w/v chitosan and 0.5% w/v potassium nitrate resulted in the highest germination percentage, chlorophyll content a and b, relative water content, and stem length. Treatment with 0.02% chitosan and 0.2% potassium nitrate resulted in the highest allometric coefficient and root length.


Highlights: Chitosan nano particle and potassium nitrate increase quinoa germination.
Chitosan nano particle and potassium nitrate increase the content of chlorophyll a and b

Extended abstract Generally speaking, plants contain various organic compounds which could influence the behavior of plant communities. These compounds are basically secondary metabolites which are found in various parts of plants such as rhizomes, roots, stems, leaves, flowers, fruits and seeds. The objective of the present study was to investigate the hetrotoxicity potential of different organs of Euphorbia maculata weed on traits of germination, chlorophyll and carotenoids pigments of wheat cultivars.
Material and In this experiment Euphorbia maculate weed was collected at full maturity stage from the Moghan region, located in Ardebil Province. Then various organs of Euphorbia maculate such as stems, leaves, and fruits were separated from each other. Another treatment namely, a mixture of different organs, was also made. This experiment was carried out as a factorial, adopting a completely randomized design with three replications in Weeds Science Laboratory of Gonbad–e- Kavous University in 2017. The first factor was wheat cultivar at two levels, consisting of Morvarid and Gonbad and organs in 5 levels (control, stem, leaf, fruit and their mixture, with equal amount of each) were the second factor. For the bioassay experiment, from each organ and their mixture, 5% suspension (w/v) was prepared, using distilled water. 10 ml of concentrated extract of each organ was applied on 50 sterilized seeds of cultivars of interest in a petri dish containing filter paper. After 7 days, traits such as rate and percentage of germination, radical length, shoot length, seed length vigor index, chlorophyll a, b and total content and carotenoids content were measured. The results showed that unlike the Morvarid cultivar, germination rate and germination percentage of the Gonbad cultivar significantly decreased, using aqueous extract of various organs of Euphorbia maculata and their mixture. The results also showed that the inhibition effect of fruit and leaf organs on the rate and germination percentage of the Gonbad cultivar were higher than that of other organs and their mixture. According to the results, stem, leaf and fruit extracts had a higher toxic effect on the radical length, compared with the shoot length of the Gonbad cultivar. The results of mean comparison also showed that seed length vigor index of the Morvarid and Gonbad cultivars decreased, due to hetrotoxic compounds of all organs of Euphorbia maculate. In terms of this trait, the highest significant decrease was found in the Gonbad cultivar, which was about 84.13%, compared with the control. In this study, the decreases in the photosynthesis pigments of total chlorophyll and carotenoids in both cultivars with aqueous extract of stem, leaf and fruit organs of Euphorbia maculata were different. The highest decrease of pigments was found in the fruit organ of the Morvarid cultivar. However, aqueous extract of mixed organs had a significant decrease and increase on the content of these pigments in the Morvarid and the Gonbad cultivars, respectively, as compared with the control. This may be due to differences in the quantity and quality of some allelochemicals as well as different reactions of the cultivars. Given the evidence of the hetrotoxicity potential of various organs of Euphorbia maculata weed on traits of germination as well as the chlorophyll and carotenoids content of wheat cultivars, it is advisable to exploit huge biomass generated by these luxuriantly growing weeds as bio-compounds in sustainable agriculture.


Highlights:1- Study of allelopathic effect of Euphorbia maculate on various wheat cultivars in farms of the Moghan plain.
2- Aqeous extract of Euphorbia maculate organs significantly reduces germination as well as seedling growth of the Gonbad cultivar

In order to evaluate the allelopathic effects of saffron (Crocus sativus L.) corm and leaf aqueous solution on germination characteristics and preliminary growth of weed species including wild barley (Hordeum spontaneum) and couch grass (Agropayron repense) two separate experiments for each species were conducted at the research laboratory of the School of Agriculture of the University of Birjand in 2016. A factorial experiment in a completely randomized design with three replications was conducted for each species. The factors included saffron organs at two levels (leaves and corms) and water extract concentrations at 5 levels (0, 0.5, 1, 1.5 and 2 percent). The results indicated that the lowest seed germination percentage of wild barley and couch grass were observed at a concentration of 2% of leaf and concentration of 2% of corm, respectively. The results indicated that the lowest rate of germination of wild barley and couch grass were observed at a concentration of 2% of leaf and corm extract, respectively. Different concentrations of leaf and corm extracts significantly decreased the length of radicle, seedling fresh weight and seedling dry weight of two weeds. The logistic model provided a successful estimation of the relationship between leaf water extract and germination percentage of two weeds. Based on orthogonal comparison tests, the allelopathic inhibitory effects of saffron leaves and corms were the same for two weeds. The results showed that leaf extract of saffron the most influence on wild barley and corm extract of saffron the best effect on couch grass. Therefore, results of this study, confirm that can be used the allelopathic effects of saffron to reduce these two weeds in the field.

Salinity is one of the most important environmental stresses that affect the growth and yield of plants. To study the effect of salinity and salicylic acid on germination of cucumber (Cucumis sativus cv. Super Dominus) and watermelon (Citrullus lanatus cv. Crimson Sweet) seeds, two factorial experiments were conducted in a completely randomized design with three replications. Treatments consisted of four levels of salinity (0, 2, 4, 6 ds/m sodium chloride) and three levels of salicylic acid (0, 0.5, 1 mM). The results showed that salinity significantly reduced seed germination and seedling growth. The lowest values of germination rate in cucumber (18.79) and watermelon (10.33), germination percentage in cucumber (86.65 percent) and watermelon (69.63) and seed vigor index in cucumber (17.93) and watermelon (9.59) was observed in 6 ds/m level of salinity. Salicylic acid improved germination parameters in both plant. The highest seed germination (97.98 percent) was obtained in the 1 mM level of SA under control condition. According to the results, pretreatment of cucumber and watermelon seeds by 1 mM SA can be proposed to improve seed germination and growth rate of seedling under salinity.

In order to study the responses of redstem filaree (Erodium cicutarium L.) seed germination to temperature levels, an experiment was carried out in a completely randomized design with four replications and twelve levels of temperature (0, 3, 5, 7, 10, 12, 15, 20, 25, 30, 35, 40 0C). Results showed that the effect of treatments on germination properties of redstem was significant, so the highest percentage of germination was achieved at 150C and reduced with increasing temperature and was totally inhibited at 40ºC. Based on linear regression between germination rate and temperature, the cardinal temperatures: minimum (Tmin), optimum (To) and maximum (Tmax) were determined: 0, 15.20 and 37.18 ºC, respectively. Significant difference was not observed in plumule length at a range of 5-30°C that showed that it is less sensitive to temperature in comparison with root length. Highest wet dry weight was achieved at 20 °C that was not different by 10, 12 and 20°C. Above results suggest that redstem failure could grow in a wide range of growing conditions, but prefers temperate zones. The results of this study are important to understand thermal requirements and improvement of management strategies of redstem filaree.

In order to evaluate the effect of salt stress on seed germination, early growth and antioxidant enzymes activity of Chicory ecotypes (Cichorium intybus) a factorial experiment was conducted based on completely randomized design with four replications at College of Agriculture, Shiraz University in 2013. The treatments were included five salinity levels [tap water (0.62), 3, 6, 9, 12 dS m-1] of sodium chloride and chicory ecotypes (Black and White). The results showed that germination rate and germination percentage were decreased in both ecotypes with increment of salinity severity. In both ecotypes, the highest germination (100%) was observed in tap water and 3 dS m-1 and the lowest germination (37%) was obtained at 12 dS m-1. The lowest root (14.2 mm) and shoot length (12.45mm) was obtained at 12 dS m-1 respectively. The effect of salt stress on antioxidant enzyme activity was significant, so that those were enhanced with increment of salt stress; however, increasing in salinity level from 9 to 12 dS m-1 was associated with reduction in peroxidase activity in Black ecotype. The results of this study revealed that the White species was more affected by increasing in salt concentration, so it had more sensitivity salt stress. The salt tolerance also had a positive relationship with the antioxidant enzymes activities in Black ecotype, especially for catalase.

This study was conducted in two factorial experiment based on completely randomized design with three replications at research laboratory of faculty of agriculture in University of Birjand in 2013. Factors included saffron organs at 2 levels (leaves and corms) and water extract concentrations at 5 levels (0، 0. 5، 1، 1. 5 and 2 percent). The allelopathic effects of saffron leaves and corms on seed germination and seedling growth characteristics of flixweed (Descurainia sophia L.) and downy brome (Bromus tectorum L.) were studied in two separate experiments. Results indicated lowest seed germination percentage of downy brome and flixweed were observed at concentration of 2% of corm extract (by 65% and 66% reduce compared to control، respectively). The rate of germination of downy brome decreased (by 71% compared to control) with concentration of 2% of leaf extract but the rate of germination on flixweed was not significantly affected by extract concentrations. Different concentrations of leaf and corm extracts significantly decreased length and weight of plumule and radicals of two weeds. A logistic model provided a successful estimation of relationship between leaf water extract and germination percentage of two weeds. Based on orthogonal comparison tests، the allelopathic inhibition effects of saffron leaves and corms were more on downy brome and flixweed، respectively.

Osmotic stress is the most important of the abiotic stresses that leads to limitation of growth and yield in rapeseed. This study was conducted to examine the effect of cycocel seed priming on osmotic stress tolerance in germination and early growth stages of rapeseed, as a factorial experiment based on completely randomized design at Agriculture College of Shiraz University in 2012. The treatments included seed priming in three cycocel concentrations: 0 (without priming as control), 2.5 and 3.5 g L-1 and osmotic stress in five levels: 0 (as control), -0.3, -0.6, -0.9 and -1.2 MPa using polyethylene glycol. The results showed that osmotic stress was significantly reduced germination percentage (15.1%), germination rate (15.3%), radicle length (29.5%), plumule length (31.6%), radicle fresh weight (22.4%), plumule fresh weight (37.6%) and vigor index (39.9%). Furthermore, osmotic stress leads to increase radicle to plumule fresh weight and radicle to plumule length ratio as 6.8 and 24.3 percent, respectively. Seed priming with cycocel reduced the adverse effects of osmotic stress on measured parameters. Although, there was no positive effect on germination percentage and rate under osmotic and non osmotic conditions for cycocel in both concentrations but cycocel at 3.5 g L-1 appeared to have a greater positive effect than 2.5 g L-1. Considering positive impact of cycocel seed priming on the reduction adverse effects of osmotic stress; further research on cycocel seed priming and osmotic stress tolerance is recommended under field conditions.

In order to study the effect of seed priming by indole-3-butyric acid (IBA) on germination characteristics of pinto bean under salinity stress, a factorial laboratory experiment, based on completely randomized design with three replications, was carried out at the Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran, in 2011-2012. Three levels of pretreatment (0, 10 and 20 mg/L IBA) and five levels of salinity stress due to NaCl (0, 1, 2, 3 and 4 dS/m) were considered. Results represented the significant effect of IBA on shoot length, root dry matter as well as allometric coefficient. Salinity had significant effect on shoot and root length, shoot dry weight, vigor index and allometric coefficient. While, interaction effect of IBA and salinity was significant only for allometric coefficient. In this experiment, the rate and percentage of germination were not affected by any of the treatments. Comparison of means showed that increasing IBA concentration resulted in an increase in shoot length (1.9 to 2.1 cm), shoot dry weight (0.03 to 0.05 gm) and allometric coefficient (0.71 to 1.06 cm), while increased salinity resulted in a decrease in root length (2.6 to 2 cm), vigor index (202.8 to 147.7) as well as allometric coefficient (1.1 to 0.78 cm). Increasing salinity increased shoot length first, and then reduced it. Overall, it appears that application of IBA for pretreatment of pinto been seeds could enhance seedling establishment under saline conditions through the improvement of root length.

Karafs Kouhi (Kelussia odoratissima M.) is one of the important medicinal plants of umbelliferae family and native of Zagros Mountains range, which is endangered due to illegal harvests. In order to accelerate breaking the seed dormancy of this plant, a factorial experiment based on completely randomized design with four replications, was carried in Faculty of Agriculture, Shahrekord University. The seeds of Karafs Kouhi from Saraghaseyed ecotype were treated under three time periods (25, 50, 75 and 100 days after planting), combination of enzylaminopurine (BAP) (concentrations of 0, 0.75 and 1.5 mg/L) and gibberellic acid (GA3) (concentrations of 0, 250 and 500 mg/L) and application methods of these growth regulators (soaking seeds in the growth regulators and use of growth regulators directly on the medium). In this experiment, germination percentage, rootlet length and hypocotyl length were studied. The results indicated that 100 days after planting significantly (P≥0.01) showed the highest rates in the three studied traits. In this treatment, the germination percentage was 86.94%, rootlet length was 9.43 cm and hypocotyl length was 11.64 cm. Moreover, the interaction of the factors was not significant for all the traits. The best combination to increase germination percent, rootlet length and germination rate, was 0.75 mg/L BAP, 500 mg/L GA3 and direct use of growth regulators. To increase hypocotyl length, only 500 mg/L GA3 is recommended.

Seed germination is a crucial stage in the plant life cycle and salt tolerance during germination stage is vital for the establishment of plants in saline soils. In order to evaluation of sesame (Sesamum indicum) landraces germination to salinity stress at different temperature, an experiment was conducted at Ferdowsi University of Mashhad, Collage of Agriculture during 2009. Experimental type was complete randomized design in factorial arrangement with 4 replications. Factors included salinity at 7 levels (0, -2, -3, -4, -6, -8, -10 and -12 bar), temperature at 3 levels (15°c, 20°c, 25°c) and 3 sesame landraces (Sabzevar, Kalat and Oltan). Results showed that germination parameters (germination percentage, germination rate, root length, shoot length, dry weight of roots and dry weight of shoots) in all landraces were significantly (p≤0.01) affected by salinity and temperature. Increasing salinity reduced all above parameters in sesame cultivars, so that highest tolerated dose of salt was obtained in 25°c and increasing of temperature reduced effects of salinity. The highest germination percent was observed in salinity between 0 to -4 bar at 25°c. Sabzevar and Oltan landraces exhibited the highest and the lowest indicators at different temperatures respectively. According to these results, it seems that in saline condition and temperature variation, Sabzevar is the appropriate sesame landraces for optimal seedling establishment.