فصلنامه پژوهش های تولید گیاهی
سال بیست و نهم شماره 2 (تابستان 1401)

Wheat is the most important crop on the land, which has always been of particular importance since its domestication and has the highest cultivated area among crops. Among the factors that reduce wheat production in the country, weeds are of particular importance and according to the studies; the average weed damage in wheat fields is 23% in Iran. This study was carried out to investigate the effect of weed control on remobilization, yield and yield components in mixed cropping of wheat cultivars and compare it with monoculture.

In order to investigate the effect of weed control on remobilization, yield and yield components in mix cropping of wheat cultivars, a randomized complete block design with three replications was conducted in research field of Agriculture College and Natural Resources of Darab, Shiraz University during 2018-2019 growing season. Experimental treatments included six levels of weed control at tillering, stem elongation, booting, ear emergence, weed-free and weedy check which in each stage, all weeds controlled manually, and cropping system treatments including of Sirvan monoculture, Setereh monocultures and mix cropping of Sirvan and Setereh, which were in a ratio of one to one.

Simple effects of weed control and cropping system on assimilate remobilization, percentage of assimilate contribution, weed biomass, plant height, 1000-grain weight, number of spike per square meter and grain yield was significant. Also, assimilate remobilization, remobilization efficiency and contribution of assimilate in treatment of weed control at tillering stage increased by 37.7%, 57.2% and 5.8%, respectively, compared to weed-free control which these traits in mixed cropping of Sirvan and Setereh increased by 29.7%, 6.6% and 18.2%, compared to monoculture of Sirvan, respectively. Results showed that weed biomass in mix cropping treatment compared to monoculture of Setareh and Sirvan decreased 29.6% and 21.25%, respectively. Also, the highest grain yield was obtained in mix cropping, which was 22.8 and 11.2% more than Setareh and Sirvan monoculture, respectively Weed control at tillering reduced grain yield as 11.9%, which had the lowest yield reduction compared to the other weed control treatments, so it may be the best time to weed control in mix cropping system.

The results showed that the mix cropping of wheat cultivars could be successful in weed control and competing, so that the weed biomass in the mix cropping had more reduction and this may be due to more canopy shading on weeds in mix cropping of two wheat cultivars. The results of assimilate remobilization showed that the dwarf cultivar of Setareh had a more efficient in assimilate remobilization and tall cultivar of sirvan by suppress the weeds at flowering has less demand for assimilate remobilization in grain filling stage. Also, the highest grain yield was obtained in mix cropping compared to monoculture and mix cropping can be used as an appropriate strategy for optimizing the use of environmental factors to increase production stability.

Climate change and rainfall patterns pose a serious ‎threat to the world's food supply to a growing population. Water scarcity is ‎currently limiting food security and economic prosperity in many parts of the ‎world. One of the solutions of the increasing the water productivity is ‎cultivation of the drought-resistant medicinal plants. Forest savory is one of ‎the native medicinal plants of Iran, which contains valuable medicinal and ‎chemical compounds. The aim of this study was to investigate the trend of ‎changes in antioxidant enzymes of two forest savory chemotypes under ‎drought stress conditions, re-watering and selenium foliar application.‎

‎In the present study forest savory chemotypes of “carvacrol/thymol/p-‎Cymene” (Darkesh chemotype) and “thymol/p-Cymene/carvacrol” (Pono ‎chemotype) with herbarium code of MPH-1347 were used. The experiment ‎was conducted in the form of a split plot experiment based on a randomized ‎complete block design. Drought were applied at 3 levels (control, moderate ‎stress (25 days without irrigation) and severe stress (40 days without ‎irrigation). selenium treatments was applied at 3 levels (0, 5 and 20 mg) as ‎foliar application. Re-irrigation was performed immediately after drought ‎stress. In order to measure enzymatic activity variation of plant 3 stages the ‎sampling was done. Including: at the end of drought stress of each treatments, ‎‎1 day and 5 days after re-watering.‎

Re-irrigation acts as a mechanism to restore physiological functions ‎that have been reduced by water stress. In other words, recovery is an ‎important component for adaptation of plants. In present study, drought stress ‎was not significantly altered the enzymatic activity of measured antioxidant ‎enzymes (except catalase in “Peno” chemotype) in both chemotypes. There ‎was also no significant reaction to selenium foliar application in different ‎levels. On the other hand, the study of changes in enzyme activity before and ‎after re-irrigation showed that, although the enzyme activity tended to reduce ‎after re-irrigation, but in the shortest possible time the activity of enzymes ‎reached to pre-irrigation conditions indicates the high resistance of this plant ‎species to drought. Also, the plant's response to drought levels and supportive ‎treatments in the two chemotypes had almost the same trend.‎

The lack of response of important antioxidant enzymes of forest ‎savory to drought stress and supportive treatments stated that this plant as a ‎drought-tolerant plant containing is suitable for cultivation in areas with ‎limited water resources and irregular rainfall. Therefore, it is suggested that ‎this plant be used for cultivation in low water conditions of Shahrood and ‎similar areas.‎

Phosphorus (P) is the second most important macronutrients and zinc (Zn) is the most important micronutrients that their deficiency is the most important global nutrient disorder in the world paddy fields. The current field study was conducted to explain the effect of Zn and P foliar application on Zn and P content of rice grains and more broadly, grains bio-fortification (Zn and protein content).

The three factors factorial experiment was conducted in a completely randomized block design with three replications in 2017-2018 at research field of the rice research institute of Iran, Rasht. The experimental factors were: varieties at two levels (Hashemi (local) and Guilaneh (improved) varieties), Phosphorous at three levels and Zinc at three levels.Also, the experimental treatments were: 1- no zinc foliar application (control-tap water foliar application), 2- the foliar application of 0.5% zinc sulphate (22%) at the strat of booting, 3- the foliar application of 0.5% zinc sulphate (22%) at the strat of booting and the start of grain filling stages; 4- no P foliar application (control-tap water foliar application), 2- the foliar application of 0.5% P(mono potassium phosphate- laboratory brand) at the strat of booting, 3- the foliar application of 0.5% P at the strat of booting and the start of grain filling stages.

The results of analysis of variance indicated that all the applied treatments and their interactions significantly influenced the morphological, yield and yield components, Zn and protein contents of rice grains. The results revealed that the foliar application of Zn and P the strat of booting and grain filling stages increased panicle length in Hashemi (7%) and Guilaneh (12.94%) cultivars, filled and unfertile grain number of Guilaneh (35.23- 6.40%) and Hashemi (40-35%) cultivars. Also, the foliar application of Zn and P (alone) increased the grain yield about 7 and 11.10%, respectively, and their application the strat of booting and grain filling stages increased biological yield of Hashemi and Guilaneh cultivars about 19.22 and 25.98%, respectively. The highest content of grain Zn and protein content were recorded at by the strat of booting and grain filling stages foliar application of Zn about 27 and 11 present, respectively.

It can be concluded that the foliar application of Zn and P at the strat of booting and the start of grain filling stages might enhanced the studied rice cultivars yield and yield component and more broadly the grain quality.

This study was conducted as a split plot in a randomized complete block design with three replications. The main This study was conducted as a split plot in a randomized complete block design with three replications. The main plot including 3 residue managements (e.g. removal, burn and incorporate). Sub-plots including 4 fertilizer managements that were: 1. chemical fertilizers of nitrogen, phosphorus and potassium; 2- Combination of vermin-compost fertilizer + potassium sulfate (before planting), super nitro-plus fertilizer + fertile fertilizer 2 (as seed treated) at planting time, humixcin organic fertilizer (foliar application) and one third of nitrogen fertilizer split; 3- (Combined 2): compost fertilizer + potassium sulfate (before planting), super nitro-plus fertilizer + fertile fertilizer 2 (as seed treated) at planting time and one third of nitrogen fertilizer split; 4- (Combined 3): Farm yard manure + potassium sulfate (before planting), Super nitro-plus fertilizer as seed treated, organic humixcin fertilizer (foliar application) and one third of nitrogen fertilizer split. Yield and yield components was selected and calculated from a surface equivalent to 2 m2. To determine the weight of the first internode (peduncle) from the pollination stage to maturity, the first internode was sampled with an interval of 10 days and placed in the oven to determine the dry weight. The most important indicators for calculating dry matter transfer efficiency were calculated.

Differences between levels of crop residue management, fertilizer management and their interaction in terms of yield components, grain yield, biological yield, harvest index, nitrogen and grain protein, remobilization rate, remobilization efficiency, remobilization share, current photosynthesis rate, Current photosynthesis efficiency, share of current photosynthesis, grain formation rate and biological yield were statistically at 1% probability level. The highest grain yield was observed in treatment of removal of residues and chemical fertilizers (4.45 t ha-1) and the removal of residues and fertilizers (1) (4.29 t ha-1) and the lowest was recorded in treatment of incorporated residues and fertilizers (2) (2.33 t ha-1). The highest grain yield formation rate was observed in the treatment of residue and chemical fertilizer removal (24.72 kg ha 1 day-1) and removal of residues and compound fertilizer (1) (23.86 kg ha 1 day-1).The lowest grain yield formation rate was obtained in the treatment of residue and integrated fertilizer (2) (12.85 kg ha 1 day-1). The highest rate, efficiency and contribution of photosynthesis were obtained in the removal of debris and the use of synthetic fertilizer (1) and the lowest was obtained in the incineration of waste and the use of synthetic fertilizer (3).

The results showed that treatments based on intensive agriculture (removal of crop residues and completely chemical management) have produced the highest grain yield. While treatments based on sustainable agriculture (Incorporated of crop residues with organic and biological fertilizers) with the highest percentage of grain protein, in fact have produced the highest product quality. On the other hand, although in Khuzestan province there is water shortage and drought stress in most cropping seasons, but according to the results obtained by incorporated crop residues, chemical fertilizers and integrated fertilizers, can increased plant growth, quality of crop production and reserve moisture in the soil and ultimately the stability of the system.

Earth monitoring satellites and vegetation indices are very useful to study the plant greenness at different stages of growth. Widely paddy fields in the north of the Iran has provided the opportunity for research related to rice crops by new technologies, but cloudy sky in plant growth periods leads to remote sensing information in humid areas is less welcomed. The existence of spatial-temporal fusion algorithms has provided the opportunity and rebuilding satellite images in cloudy periods to use remote sensing data in the period of plant growth. In this study, spatial-temporal fusion algorithm were used to rebuilding the images of Landsat 8 and Sentinel 2 satellites during the growing season of rice to estimate the leaf area index as a representative of vegetation health and development at different stages of growth.

To achieve the objectives of this study, images of Landsat 8 and Sentinel 2 satellites were used. In the cloud period, with the help of STARFM algorithm, two satellite images were rebuilt and used to extract Normalized Difference Vegetation Index (NDVI), Rice Growth Vegetation Index (RGVI) and Soil Adjustment Vegetation Index (SAVI).To estimate leaf area index by satellite images, a suitable relationship was obtained between vegetation indices and rice leaf area index at different stages of growth.

Due to the cloudiness in July and the peak of greenery of the rice plant, using the STARFM algorithm to rebuild the images was very efficient. With the help of 15 images in the whole rice growth period (90 days), four linear relationships were established between Normalized Difference Vegetation Index (NDVI), Rice Growth Vegetation Index (RGVI) and Soil Adjustment Vegetation Index (SAVI) for four stages of growth with leaf area index. The highest and lowest correlation coefficients were observed between vegetation indices and leaf area index of 0.96 for NDVI index in transplanting and maturing stage and 0.75 for RGVI index in transplanting stage, respectively. Also, the map of changes in leaf area index for both satellites during the crop growth period showed well the changes in the greenness of rice cover.

In general, it seems that by using satellite data and image rebuilding on cloudy days, it is possible to achieve the leaf area index with high accuracy and extract various information such as age and growth stage for the rice plant

Orchids, especially Phalaenopsis orchids, are known as one of the most popular ornamental plants in the world markets. The use of in vitro cultivation system is the only way to produce these orchid plantlets. Producers of this plant have to buy and import it from foreign companies. Currently, increasing the costs of plantlet production and cultivation in the country, which requires the buy of imported chemicals for prepare in vitro culture media, has caused problems for domestic producers of this product. Therefore, making a suitable and low-cost culture medium to produce inexpensive and high-quality tissue culture seedlings on a commercial large scale was the main purpose for this study.

In this study, 5 mm protocorm explants were cultured in eight treatments of culture media (including 1/2 MS (control), FAST and six types of hand-made medium used of made in Iran inexpensive fertilizers with numbers one to six (M6 to M1) were named) and three replications in a completely randomized design. Explants were subcultured every 30 days and their total fresh weight was recorded. Also, three months after cultivation, some physiological traits (total fresh and dry weight, leaf and root dry weight), biochemical (concentration of photosynthetic pigments, anthocyanins and soluble, storage and total carbohydrates) and maximum efficiency of photosystem II were measured in plantlets.

The results showed that plants grown in different culture media in all traits had a significant difference at the level of 1% probability. The highest total fresh and dry weight, photosynthetic pigments and the maximum efficiency of photosystem II, occurred in M5 and M6 culture media and the lowest in M2. Also, M6 with 155.7 and 1/2 MS 40.2 mg g-1, respectively, had the highest and lowest total carbohydrate content. The highest (31.3 μmol g-1) and lowest (14.9 μmol g-1) anthocyanin content were observed in M2 and 1/2 MS culture media, respectively.

By adding banana powder and activated charcoal to M5 (300,000 Rials and 7.15 $) and M6 (440,000 Rials and 10.52 $) inexpensive culture media compared to orchid conventional culture media (1/2 MS and FAST) and reducing in vitro cultivation costs 23% and 12%, respectively, were selected as suitable low-cost solid culture media for growth and development of Phalaenopsis orchid plantlets, which according to the biomass partitioning curve can be introduced M6 as an inexpensive and suitable culture medium due to the production of more well-formed plants in comparison of all culture media.

Determining the classification, phylogenetic relationships, and genetic diversity in citrus is critical to determining genetic relationships, identifying germplasm, controlling genetic erosion, establishing breeding programs, and registering new cultivars. Researchers believe that genetic diversity is very important and is an essential part of any breeding program. The use of molecular techniques to assess DNA level, genetic diversity, and genetic distance is widely used in germplasm samples. Therefore, the aim of this study was to investigate the genetic diversity of orange genotypes using molecular markers.

In order to investigate the genetic diversity, 40 orange genotypes of Rudsar city in Guilan province were evaluated. DNA extraction from young leaf samples was performed using the Edward method with slight modifications. After DNA extraction of genotypes, polymerase chain reaction (PCR) was performed with 15 primers. Amplified genomic DNA images were analyzed and the data were entered into Excel software as a matrix. Polymorphic information content, marker index, effective multiple ratio, number of effective alleles, Shannon index and straw gene diversity were also examined.

The 15 primers used in this study were able to create a total of 140 bands, of which 101 were polymorphic bands, including TOS-1 and TOS-2 primers with 9 bands, UBC811 primer and UBC8821 + UBC826 hybrid primer with 4 Tape created the least number of polymorphic strips. Primers TOS-1, UBC813, UBC823 and TOS-2 and UBC811 with the highest PIC value, best markers and high values of effective allele, Shannon index, straw gene diversity as the top primers to study genetic diversity in this study, respectively were. Based on the results, the markers used were able to evaluate the genetic diversity of genotypes. The content of polymorphic information in this study ranged from 0.22 to 0.45. Principal coordinate analysis showed that the first three components were able to explain a total of 29.08% of the total variance. Cluster analysis by the farthest neighbor method divided 40 orange genotypes into five distinct groups based on similarities and differences. The grouping accuracy obtained from the cluster analysis was confirmed by the Fisher linear focal detection function 100%. The markers used in this study showed acceptable polymorphism. Also, the study of morphological traits and molecular markers used in this study showed the degree of similarity and differences of genotypes, although there were differences in the results of morphological and molecular studies that can be observed. Due to the high accuracy of molecular markers. However, using appearance and morphology, it was possible to distinguish orange genotypes from each other.

The results of this study showed that there is a high genetic diversity among orange genotypes. Due to the fact that the markers used in this study showed acceptable polymorphism, they can be used in future research on this plant and other citrus plants. In general, according to the results of this study, that ISSR and retrotransposon primers can be used as a simple molecular method based on PCR and relatively safe and reliable in determining the level of genetic diversity and phylogenetic relationships in citrus.

Because of the growing population and the pharmaceutical industry's urgent need for medicinal plants as raw materials for drug production, as well as the importance of their active ingredients in the food, cosmetics, and health industries, there has been increased interest and research on these plants in terms of cultivation, production, and consumption. Drought, as the most important non-living factor limiting plant growth and yield, causes or worsens other stresses, particularly nutrient deficiency stress in plants. Primary metabolite production decreases and increases with secondary metabolite production under drought stress conditions. The purpose of this study was to determine the effect of drought stress, phosphorus fertilizers, and planting methods on some morphological and physiological traits, seed and mucilage yield of the medicinal plant isabgol.

This experiment was carried out as a split-factorial in the form of a randomized complete block design with three replications at Zabol University's research farm in Chah Nimeh. The experimental treatments included three drought stresses, irrigation after 60, 120 and 180 mm evaporation from a class A evaporator as the main-factor, and the combination of seed planting method (flat or ridge planting) and types of phosphorus fertilizer (100% chemical phosphorous fertilizer, Phosphate Barvar2, and 50% chemical phosphorous fertilizer + Phosphate Barvar2) as the sub-factor. Plant height, number of leaves per plant, number of fertile tillers, seed and biological yield, mucilage yield, SPAD index, ionic leakage percentage, and relative leaf water content were the traits studied.

The results showed that the most plant height, number of leaves per plant, number of fertile tillers, seed and biological yield, mucilage yield, SPAD index and relative leaf water content were obtained in the greatest quantity from irrigation treatment after 60 mm of evaporation from the evaporation pan, with the exception of ionic leakage, which was obtained in the greatest quantity from irrigation treatment after 180 mm of evaporation from the evaporation pan. With the exception of ionic leakage, the combined bio-chemical fertilizers of phosphorus increased the studied traits. Also, except for ionic leakage, which had the highest values from the ridge planting method, the flat planting method increased the evaluated traits. The highest biological yield (6201 kg ha-1) is associated with irrigation treatment after 60 mm evaporation from evaporation pan with combined application of phosphorus fertilizers in flat planting method, and the highest ionic leakage (48%) is associated with irrigation treatment after 180 mm evaporation from evaporation pan with no fertilizer application in ridge planting method.

According to the findings, using irrigation treatment after 60 mm of evaporation from the evaporation pan and a combination of chemical and biological phosphorus fertilizers in a flat planting method can result in increased production of the medicinal plant isabgol.

Drought stress reduces the water potential of the soil and in such conditions the plant can osmoregulation in order to preserve and continue water absorption. Osmoregulation in flag leaf and pollen grains can be used as an indicator in wheat breeding programs to increase drought tolerance. The aim of this study was to study drought tolerance and selection of the most tolerant genotype of wheat through the effect of different irrigation regimes on chlorophyll, proline, osmoregulation of pollen grains and selection of the best genotypes for planting in arid and semi-arid regions with high yield.

In order to analyze the effects of three different humidity regimes on the osmoregulation of pollen grain, chlorophyll and proline content three different experiments were carried out in randomized completely block designs with three replications. The three different humidity regimes included normal conditions (without stress), water-stress in meiosis stage and continuous water stress (30% of Field Capacity). The genotypes studied in this experiment included Alvand, Ehdaei 81, Ehdaei 82, Oxley and Chinese Spring.

The results of analysis of variance in non-stress and stress conditions showed that there was a significant difference between genotypes in terms of most traits. The reaction of wheat genotypes was different in three experiments, but drought stress increased proline content and decreased chlorophyll content in all stresses. Chinese Spring genotype under normal irrigation conditions and stress in meiosis stage and 30% field capacity stress by storing more proline and chlorophyll and preventing the decomposition of these materials were identified as the most drought tolerant genotype. Osmoregulation has a positive relationship with grain yield and genotype Ehdaei 82 have the ability of osmoregulation and high grain yield under drought stress conditions in the meiotic stage. Under different water conditions, the higher Projected pollen grain area PEG 50% and the smaller Projected pollen grain area PEG 30%, Osmoregulation increases significantly.

The results showed that drought stress reduced the evaluated traits and genotype is more tolerant to drought that stores the highest content of proline and chlorophyll in leaves. Chinese Spring genotype was the most tolerant genotype with the highest content of proline and chlorophyll and high osmoregulation under normal irrigation conditions. Chinese Spring is in the group of genotype does not have the ability of osmoregulation and is suitable for dry conditions. This genotype is adapted to stress conditions by using other drought tolerance mechanisms and if improved for osmoregulation under stress conditions, it can be more adapted for cultivation in arid areas.

Wilt disease caused by the pathogenic fungus Verticillium dahliae is one of the dangerous factors threatening the cultivation of pistachio trees in the country, which has spread in different parts of the country in the last two decades, including Semnan province. Lack of suitable fungicides to control V. dahliae and continuous use of several common fungicides in the country has contributed to the spread of the fungus. Therefore, in the current situation, we need to use new compounds with high efficiency to control this pathogenic fungus. Plant essential oils and their monoterpene compounds are considered as one of the important options due to the comparative advantage of the production of medicinal plants in the country.

In this study, V. dahliae native isolates obtained from gardens of Semnan province were used. Isolation and identification process was performed using conventional methods and isolates were identified using general ITS primer. Then, the essential oils of thyme (Zataria multiflora) and Peppermint (Mentha piperita) were used to evaluate the antifungal effect. After preparing the herbal plants, the essential oil extraction process was performed using Clevenger method. The antifungal effect was investigated by mixing with culture medium at concentrations of 20, 40, 60, 80 and 100 μg/ml. Also, the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MBC) were determined for the two essential oils. Then, using thymol and carvacrol monoterpenes, antifungal effects were tested by mixing with culture medium at three concentrations of 15, 150 and 1500 μg/ml against V. dahliae.

Isolation and identification tests confirmed the presence of V. dahliae in the sampled areas. The use of ITS primer confirmed the fungal species V. dahliae. The results of antifungal effect showed that both essential oils were effective in preventing the growth of fungi, but Zataria multiflora essential oil was evaluated as stronger, so that in the third week, growth was observed only at a concentration of 20 μg/ml, but in the case of peppermint essential oil, fungus growth was observed in all concentrations. The results showed that the minimum inhibitory (MIC) and minimum fungicidal (MFC( concentrations were 20 and 30 μg/ml for thyme and 100 and 150 μg/ml for peppermint essential oils, respectively. In addition, the results showed that thymol was more potent than carvacrol in preventing the growth of V. dahliae.

The results of this study showed that plant essential oils and monoterpene compounds of essential oils had a very high ability to control Verticillium fungus, so that compared to common fungicides in the country, their inhibitory concentration was 10 to 15 times lower

Lilium ledebourii Bioss is a rare species belonging to the Liliaceae family, containing valuable secondary metabolites. This flower is one of the most popular plants in the word which used as a cut flower, pot flower and bedding plants .Micro propagation was done in this flower by used of different hormonal combinations and elicitors. The goal of this study was to evaluate the effects of various nitrogen ratios on in vitro regeneration and secondary metabolite production.

In order to study the effects of different nitrogen ratios on the regeneration and secondary metabolite production of Lilium ledebourii, an experiment was conducted based on the completely randomized design with 10 treatments and 8 replications in tissue culture and biotechnology laboratory of the Horticultural Department of Mohaghegh Ardabili University. The MS medium were used to culture the explants. In this experiment some morphological traits were evaluated such as fresh weight, plant height, leaf number, leaf length, root number, root length, bulblet number, bulblet diameter and scale number. The measured biochemical traits were total Chlorophyll, chlorophyll b, chlorophyll a, carotenoid, Flavonoid in 3 different waves (270, 300 and 330 nm), anthocyanin and phenol.

The results of the experiment showed that various treatments significantly (P≤0.05) affected total phenol content, anthocyanin, chlorophyll a, b, and total chlorophyll, fresh weight, seedling height, regenerated root and bulb number. The highest value of total phenol and anthocyanin contents, fresh weight and seedling height was observed in nitrate to ammonium ratio of 40:40. However, the best treatment for chlorophyll a, b and total chlorophyll, was the ratio of nitrate to ammonium at the rate of 60:25. Also, in the case of root and bulblet number, the best treatments were ratios of nitrate to ammonium at the rates of 40:40, 40:25, 60:25 and 40:0. The comparison of means of dada showed that the highest content of carotenoid (4.838 mg/g Fw) was obtained from 80:25 ratio of nitrate to ammonium which had the significant differences with control and other treatments. However, the lowest content of this index was observed in nitrate to ammonium at the rates of 40:120 and 0:25 which also had the significant differences with control.

In general, the nitrate to ammonium ratio of 40:40 in compared to the other treatments had the better effects of measured indices and accumulation of ammonium in the plants texture was interrupted for the normal growth.

Common morning-glory (Ipomoea purpurea L.) is one of the most important harmful weeds in summer crops in Golestan province. Germination is one of the most important stages of plant life and the study of environmental factors affecting the germination of weeds is necessary for their proper management.

In order to investigate the effect of some environmental and management factors on seed germination and emergence of common morning-glory, experiments were conducted in the laboratovar and research greenhouses of the Gorgan University of Agricultural Sciences and Natural Resources in 2017. In this study, common morning-glory response to constant temperature (5, 10, 15, 20, 25, 30, 35, 40 and 45 ° C), alternating temperature (5:15, 10:20, 15:25, 20:30) , 25:35), high temperature (temperatures of 50, 80 and 100 ° C for 5 and 10 minutes), drought (0, -0.2, -0.4, -0.6, -0.8, -1 MPa), salinity (0, -0.2, -0.4, -0.6, -0.8, -1, -1.2 and -1.4 MPa), pH (4, 5, 6, 7, 8, 9), burial depth (0, 1, 2, 3, 5, 7, 9, 11, 13, 15 and 17 cm) and flooding duration (0, 3, 5 and 7 days) were examined.

Constant and alternating temperatures had a significant effect on the germination percentage of common morning-glory. The highest germination percentage were observed at constant temperatures of 30 and 35 °C and at alternating temperatures of 15: 25 and 20: 30 °C (day / night). Based on the Dent model, Cardinal temperatures of seed germination of this plant including base, optimum upper and lower and ceiling temperatures were 7, 30, 35 and 44 °C, respectively. Germination of of common morning-glory seeds decreased with increasing salinity and drought. The concentrations of sodium chloride and polyethylene glycol, which reduced the germination of this plant by 50%, were equal to -1.06 and -0.45 MPa, respectively. This indicates that this plant is resistant to salinity and there is a possibility of its development in saline lands of the country. Germination of this plant in pHs of neutral and alkaline were significantly higher than acidic pHs. At high temperatures, the percentage of germination and seed viability decreased significantly. The percentage of common morning-glory seed emergence at burial depths of 1 to 7cm were not significantly different (92 to 100%). With increasing depth from 9 to 13 cm, the percentage of emergence decreased significantly and no seeds emerged from a depth of 15 cm. Therefore, the use of non-tillage and low tillage methods can not have much effect on the management of this weed; Unless deeper plowing is used. Results showed that seed germination of this plant is very sensitive to flooding stress.

The results of the present study showed that environmental factors have a significant effect on the germination and emergence of common morning-glory and they can be used in designing effective management scenarios to control of this weed.

Olive (Olea europaea L.) seed face two problems (physiological and mechanical dormancy) for germination. Various treatments such as mechanical scraping, chemical scraping and cold stratification (wet cooling) are used to accelerate seed germination. Concentrated sulfuric acid is used to relieve mechanical dormancy and to eliminate physiological dormancy, wet cold stratification is used. In the present study, in order to eliminate seed dormancy, accelerate germination and obtain suitable seedlings to produce rootstocks compatible with climatic conditions of Rudbar city, seeds of Arbequina, Balidi and Mari cultivars were used and cold stratification and sulfuric acid were applied. Also, the effect of seed harvest time on germination rate was investigated. Seeds were harvested from fruits of olive trees cultivars Arbequina, Mari and Balidi at Rudbar Olive Research Station. The first time of harvest was the stage of full ripening of seeds with change of olive color from green to yellow (early October) and the second time of harvest was the stage of full ripening of fruit with change of color to purple and blackening (late November). The pots were filled with rotten animal manure and river sand. Three seeds were planted in each pot. The cultivation bed and seeds were disinfected with carbendazim disinfectant at a rate of two per thousand. All treatment levels (36 levels) had 4 replications. Experiment as factorial and in the form of completely randomized design with four replications was performed. Factors included varieties at three levels (Arbequina, Balidi and Mari), harvest time at two levels (full seed ripening and full fruit ripening), cold stratification with the temperature of 6-7°C at three levels (0, 500 and 1000 h), and 97% concentrated sulfuric acid treatment at two times (0 and 9 h). Therefore, the present experiment had 36 treatment levels. For each cultivar, 240 pots in 12 levels (6 levels in the first stage of harvest and 6 levels in the second stage of harvest) and 20 pots in each level were used. Totally, 2160 seeds were used for 720 pots for three cultivars. Germination rate, germination average, germination percentage, germination vigor and vegetative growth indices such as shoot growth and seedling dry weight were measured. The data were analyzed using SPSS software and their mean was compared using LSD test at 5% probability level and EXCEL software was used to draw the graph. Analysis of variance of the data showed that there was statistically significant difference (p≤0.01) between treatments and measured traits in various cultivars. There was no significant difference between cold priming and acid priming and sprouted seed number and plantlet vigour index. The results showed that the combined treatment of Mari cultivar seed with 9 h of sulfuric acid treatment and 1000 h of cold stratification treatment induced the highest germination vigority. The combined application of cold priming and sulfuric acid in the second stage of harvest (after full fruit ripening) reduced the number of days to germination but increased the germination percentage, germination rate, germination average and seedling vigor index in all cultivars. In all three cultivars, the highest plantlet dry weight was obtained from the 500 h cold priming. The production of more and stronger olive seedlings is important for the development of olive gardens in the olive-growing provinces of the country economically, ecologically and to prevent soil erosion, especially in sloping lands. In this study, an effective solution to increase the germination index of olive seeds was presented. Among the different olive cultivars used, Mari cultivar showed more and better response to priming, which was more evident in the second harvest.

The greenhouse crops recently attract enormous interest in Iran. The extensive greenhouse tomatoes cultivation, established for local and export markets. The salinity of irrigation water is one of limitation factors of greenhouse crops cultivation in arid and semi-arid regions. In this research, survey impact of melatonin and salicylic acid in reducing the destructive aspects of water salinity stress in the early stages of greenhouse tomato growth.

In a factorial split-plot experiment, tomato plants, Goldi cultivar, were exposed to salinity at 0, 50, and 100 mM NaCl as a main factor in hydroponic culture medium. Two sub-factors, Melatonin at 0, 10 μM and salicylic acid 0, 1.5 and 2.5 mM, were foliar sprayed in three time. Before flowerings, one month after transfer to the pot, shoot height and leaf length, leaf number and stem diameter were measured. Two months after planting, fruit weight, number of flowers per inflorescence and chlorophyll fluorescence parameters including minimum fluorescence (Fo), maximum fluorescence (Fm), variable fluorescence (Fv) and photochemical quantum yield (YII) were measured.

The results showed that salinity significantly reduced the vegetative and reproductive growth of tomatoes in greenhouse conditions but salicylic acid did not show a significant effect on vegetative and reproductive characteristics in the early stages of growth. Melatonin significantly increased the growth characteristics of tomato plants such as leaf length and number, plant height and stem diameter in the first month of growth (P <0.01). The results also showed that melatonin had a significant effect on increasing the number of flowers in the inflorescence and the number of fruits per plant in the two months after planting. Also, fluorescence parameters including Fm, Fo, Fv and YII showed a significant decreasing with increasing sodium chloride concentration (P <0.01). The average effective photochemical quantum efficiency of photosystem II decreased from 0.84 in non-stress conditions to 0.76 in salinity. Melatonin caused a significant increase (P <0.01) in the effective photochemical quantum efficiency of photosystem II and maximum and minimum fluorescence of tomato plants, but the application of salicylic acid had no effect on this parameters. The most effective photochemical of photosystem II was 0.84 in non-stress conditions and application of 10 μM melatonin.

The results of this study showed that salinity reduces the initial growth of tomato plants under greenhouse conditions. Salicylic acid did not show a significant effects on vegetative and reproductive characteristics in the early stages of tomato plant growth. Use of melatonin reduces the destructive effects of salinity and increases tomato tolerance to salinity in the early stages of growth.