محمدحسین اهتمام

In cut rose flowers, petals senescence not only confines the ornamental value but also imposes a significant economic loss. Therefore, delaying the senescence of cut rose flower petals senescence is very significant to acquire high commercial benefit. In this regard, research was conducted to investigate the effect of the application of the new technology of enrichment with oxygen nanobubbles and silicon nano chelate in the conditions of soilless cultivation on the physiological indicators, the stomatal condition, and the vase life of cut roses. The current research is a factorial split-plot experiment in the form of a randomized complete block design with three factors, including two cut rose cultivars (Samurai and Jumilia), nutrient solution enrichment with oxygen nanobubbles (with oxygen nanobubble concentrations of 0 and 20 mg/liter and for 4 minutes per hour), and foliar spraying of 2% silicon nanochelate (with a concentration of 0 and 2 ml L-1 and an interval of 10 days) with three repetitions. Application of silicon nanochelate compared to the control treatment resulted in 13.4%, 15.6%, 25.6%, 18.3% and 28.3% improvement in leaf area, chlorophyll a, chlorophyll b, total chlorophyll and carotenoid content, respectively. Interaction of oxygen nanobubble and silicon nanochelate content of chlorophyll a (14.7%), chlorophyll b (26.1%), total chlorophyll (18%), carotenoids (27.2%), stomatal area (7.41%), and diameter increased stomata (4.48%), stomata length (7.30%), stomata width (6.49%), and the ratio of the number of open to closed stomata (53%) compared to the control. The use of oxygen nanobubbles had a more pronounced effect compared to silicon nanochelate, which can be introduced as an indicator treatment for increasing the post-harvest life and quality of rose-cut flowers.

Salinity of soil and water is one of the most serious environmental problems in the world. Medicinal plants are one of the most valuable resources in a wide range of natural resources in Iran which if scientifically recognized, cultivated, developed and exploited properly can play an important role in public health, job creation and non-oil exports. Therefore, this experiment was performed on farm of Isfahan University of Technology and A factorial randomized complete block design was used for performing this experiment. Four levels of salt treatment (i.e. 0, 40, 80, and 120 mM NaCl) were applied on two genotypes from each of the three species of fennel, ajwain, and anise in three replications. Chlorophyll a and b, leaf starch, sodium and potassium concentration and their ratios, phenolic compounds, H2O2, grain yield, 1000-grain weight, root and shoot dry weight as well as height were measured. The results showed that salinity levels had different effects on different traits of these three species and their genotypes. With increasing salinity, dry weight of roots and shoots, height, yield, 1000-seed weight decreased, and on the other hand, H2O2 concentration and phenolic compounds and antioxidant capacity ramped up with increasing salinity level. Starch was different in the studied species and genotypes, so that the concentration of chlorophyll in fennel genotypes increased to a level of 80 mM salinity and then ramped down, but in the other two species had a decreasing trend: sodium concentration and sodium to potassium ratio with increasing Salinity levels increased and this increase was more noticeable in anise, the potassium concentration in all three species with The increase in salinity decreased, but the largest decrease was related to the anise plant. In general, according to our findings, anise is more prone to damage due to salinity stress, while the salinity tolerance of fennel and alder is comparable, although the salinity tolerance, especially in the latter two species, is subject to genotypic differences.

Rose is one of the most important genera of the Rosaceae family and Rosa damascena Mill. is the most prominent rose cultivated in Bulgaria, India, Turkey and Iran to produce perfume. In order to identify populations of R. damascena, morphological characteristics of this species were considered as the first and most important criterion in explaining the genetic status. Samples were taken from 750 hectares of Kashan and other areas of Isfahan province such as Meymeh (Ziyad Abad), Chadegan, Semirom and Najaf Abad and in each specimen, the shape and color of the stem, spiny or spineless, leaf shape and its length, number of leaflet, length and width of terminal leaflet, color of upper and lower of leaf, edge and base of leaf, color and number of petals, number of stamen and at the end of season, shape and color of fruit and number of seeds per fruit were evaluated. Also, the morphology of ornamentation of seed surface of these populations was studied and compared using scanning electron microscopy. According to the results, the morphological traits of different populations known as Kashan and Kazeroon were not different, but the populations known as Tabriz and Meymand showed significant differences in number of spine, shape of fruit and seed number in fruit. No significant differences were observed in seed cover decorations for all types of R. damascena populations and this trait could not be used for separation of different populations.

To study the effect of salinity on physiological, biochemical and anatomical characteristics as well as the growth and yield of different accession of melons a split plot experiment was designed based on RCBD with 3 replicates on 3 accession, resistant (annanasi), semi tolerant (Sabz Isfahan) and sensitive (Gongi) and two salinity levels (0 and 8ds/m according to salinity of wells) in the field of Isfahan research station in 2016-2017.Results were shown that the fresh and dry weight of shoots decrease with salinity in all accessions. Fresh and dry weight of pulp, skin and seeds, number and fruit weight decreased in sensitive and semi tolerant. Yield decrease in all accession. friut firmness in all acession and friut acidity decresed in semi tolarant and sensetive and TSS increased.the greatest decreas of photosynthesis, stomata conductance, and CO2 of stomata in sensetive acession. Transpiration and leaf water potential was more minus. The highest amount of proline, phenol and antioxidant activity was observed in resistant accession. Upper epidermis thickness increased in sensitive accession with salinity and did not change in lower epiderm of leaves. the aim of this researc was introducing the tolarate acsession to salinity result in introducing Ananasi.

Microcharacters of seed coat and its surface patterns are valuable in the systematic consideration in some genera. The aim of this study was to introduce the application of these data in assisting the identification of Vicia L. species.Micromorphological traits of 90 seeds from 20 species of the genera of the Vicia were studied in order to answer some systematic questions regarding this genus. The morphology of the surface of these species were examined using a scanning electron microscope (SEM). The results of the observations and analyses indicated that the pattern of seed coat ornamentation was of Papillose type and their SEM pattern varied within and between accessions in terms of tip-shape of the papillae, size (height), and amount of conation of papillae side ride. These traits can be used in taxonomic revision of the Vicia genus. Based on these seed coat ornamentation traits, four categories namely Colliculate with Tuberculate, Aculate projections from projections peaks, Aculate and Tuberculate from below the peak were identified. These analyses can provide good evidence for the close relationship of related species from the different species in a genus. It presents a comprehensive guide regarding variety classification and cultivar introduction.

This study was performed in order to evaluate the drought tolerance of some safflower genotypes in a field experiment carried out at the research farm of Isfahan University of Technology located at Lavark, Najaf-Abad, Iran (40 km south west of Isfahan, 32º 32´ N, 51º 23´ E, 1630 m asl). In this study, five genotypes including A82) interspecific hybrid), landrace Kooseh, Goldasht, C111 and Ac-stirling were evaluated in a randomized complete block design with three replications at two moisture levels (normal and 90% water-depletion), separately. Seven drought tolerance indices including Stress Tolerance Index (STI), Tolerance Index (TOL), Stress Susceptibility index (SSI), Mean Productivity (MP), Geometric Mean Productivity (GMP), seed yield in stress (Ys) and non-stress (Yp) environments were calculated for each genotype based on seed yield under stress and normal conditions. The results analysis of variance showed that there were significant differences among the genotypes for all traits. The drought stress had significant effect on head diameter, number of heads per plant, number of seeds per head, seed weight per head and seed yield. Mean comparisons showed that control genotypes were significant differences for all studied traits except seed weight per and seed yield traits with the genotype A82 under non stress and stress conditions. Principal component analysis (PCA), indicated that the first and second components justified 91% of variations between drought tolerance indices. First vector showed 67% of the variations and was recognized as yield potential component and drought tolerance indices (MP, GMP, STI) and the second rector justified 24% of total variations which would be named as “drought susceptible components (TOL and SSI indices). Biplot analysis also indicated that STI, MP, GMP were more reliable indices to identify drought tolerant safflower genotypes and discriminated Goldasht genotype and genotype A82 as the most drought tolerant. The indices STI, GMP, MP identified the Goldasht  and A82 genotype as a drought resistant genotype and this genotype was obtained from interspecific crosses between cultivated safflower (Carthamus tinctorius L.) and wild species (C. oxyacanthus). This genotype had the highest grain yield under stress and non-stress conditions. Therefore, it could be used in safflower breeding programs to improve drought tolerance.

Stachys lavandulifolia Vahl. is one of the most important medicinal plants with different applications in pharmaceutical and sanitary industries as well as high distribution in Iran. In order to assess the morphological variation and cutting times in S. lavandulifolia genotypes, an experiment was carried out in a randomized block design with three replicates on 41 genotypes belonging to four regions including Ferydoonshahr, Damaneh, Semirom and Shahrekord. According to analysis of variance, significant differences were observed among all traits studied, while no significant differences were observed among replications. The results of mean comparison revealed that the genotype Damaneh7 in the second cutting time possessed the highest dry weight. Shahrekord 6 in the first cutting time had the highest days to flowering with 100 days. Moreover, Damaneh20 genotype in the third cutting time had the highest essential oil content (3.11%), while the lowest was obtained for Damaneh17 genotype in the first cutting time (0.04%). In general, a significant variation was observed between genotypes and different cutting times. Finally, according to cluster analysis, genotypes were divided into different clusters based on different cutting times.

Due to environmental hazards and risks of chemical control of weeds, sustainable weed management is considered. A concept interactions of interference in plants is allelophatic effects. Which can play an important role in control weeds. Achillea L. is one species of plants with allelophatic activity. By considering abundance of Achillea species in Iran, an experiment in the years 2013-2014 on the collection Achillea species Isfahan University of Technology was implemented. In this experiments aqueous extract from two Achillea species collected from different area in Iran, including A. nobilis (of Isfahan), A. pachycephala (of Golestan) and A. pachycephala (of Hamadan) on Amaranthus retroflexus at concentrations of 0, 3, 6, 12, 25, 50 and 100 percent was performed. The results showed that various concentrations of aquous extract have different effects on species and their characteristics. The genotype A. pachysephala of Hamedan have stronger effect and genotype of Golestan have the lowest effects. Extracts in concentrations between 3 to 12% have a stimulatory effect and in concentrations of 25 to 100% showed inhibitory effect.

Depending on the fuel type, the main vehicle exhaust emissions are nitrogen oxides (NOx), carbon oxides, sulfur oxides (SOx), carbon particles, heavy metals, water vapor and hydrocarbons including aldehydes, single hydrocarbons and polyaromatic hydrocarbons, alcohols, olefins, alkyl nitriles that along with secondary pollutants such as ozone, have negative effects on plant health. Agricultural lands which are adjacent to urban areas, are increasingly vulnerable to vehicle pollution.
The plants suffer a lot from the pollution caused by exhaust of vehicles because they can not move away from the source of contamination.
Plants exposed to exhaust of vehicles, show many disruptions in their general appearance, which are referred to as "visible injuries". In fact, these visible damages to the plants reflect the physiological changes that come with the contaminants. These physiological changes may be considered as "hidden injuries".
There is concern about the compounds of contaminants, because there is an evidence that the plant response to multi-pollutant mixtures may be different from plant response to a pollutant. For example, one hour exposure to combination of SO2 gases with concentration of 1310 micrograms per cubic meter and NO2 with concentration of 940 micrograms per cubic meter resulted in low leaf damage, while none of the gases do not cause damage alone in this concentrations.
There are many reports on the effects of pollutants on the anatomy, physiology and morphology of different plant species.
The importance of stomata in plant protection against air pollutants has been investigated and it has been shown that the closure of stomata helps to protect plants from pollution damage.
Vehicle contaminants affect photosynthesis and cause oxidative stress in plants.
Air pollution caused a significant increase in membrane peroxidation in Lavandula officinalis Chaix. and Ligustrum vulgare L. planted in the margin of the streets of polluted and cleaned areas of Tehran.
The activity of Antioxidants enzymes (catalase, peroxidase and ascorbate peroxidase) increased in different levels in contaminated areas compared to clean areas.
There are not enough researches on the effect of gasoline exhaust pollution on leafy vegetables, especially spinach.
According to the considerable amount of cultivated spinach, especially in Iran are in outdoors and on the side of the roads or contaminated urban areas, therefore, the effects of the gasoline exhaust pollutants on some anatomical, physiological and morphological characteristics of spinach (spinacia oleraceae var virofly) was investigated.
Material and

The experiment was conducted in factorial test based on a completely randomized design with three replications in greenhouse of Isfahan University of Technology.
12 small chambers (length: 100 cm, width 70 cm and height: 70 cm) and an exhaust generator for transferring the contaminants to the chambers were constructed.
VARIOPLUS MRU device was used to analyze the output gases and determine the concentration of contaminants from burning gasoline.
The seeds of Spinacia oleraceae var. viroflay were directly cultured in pots No. 4 which were filled with sand and soil mixtures of 1:2.
When the spinach seedlings reached to 4-leafy stage, transferred to the chambers and exposed separately to the gasoline exhaust pollution for three hours in three different exposure times (10, 20 and 30 days) and after the exposure time, their anatomical, physiological and morphological traits of plants were measured and compared with control plants.
The relative water content was measured by the method of Ritchie et al. (1990). Electrolyte leakage was measured by Lutts et al. (1995).
The total chlorophyll content and carotenoid content of leaves were extracted by 100% acetone solvent method. The absorbance of light at 661.6 and 168.8 for total chlorophyll and 470 nm for carotenoids were read.
The chlorophyll fluorescence concentration was measured by a chlorophyll meter machine (OS-30P model manufactured by Opti-science, UK) and the Fv/Fm ratio (photochemical effect of photosystem 2) was reported.
Factors related to leaf gas exchange were measured by a portable photosynthesis measurement (LCi model manufactured by ADC Bioscientific Ltd, UK). The amount of proline was measured using the Bates method (1973).
Catalase activity was measured using modified Aebi method (1984) at 240 nm wavelength. Ascorbate peroxidase activity was estimated by modified Nakano and Asada (1981) by absorbance reduction at 290 nm. The activity of the guaiacol peroxidase enzyme was determined by the Chance and Maehli method (1955) with a slight change.
Anatomical traits were observed by optical microscope and measured through the Edn-2 software.
Statistical analysis of data of all traits were performed using statistical software Statistix 8 and comparison of meanings performed based on minimum significant difference test (LSD) at 5% probability level.
Discussion of

Anatomical, physiological and morphological characteristics of spinach plants affected by gasoline exhaust pollution in every three exposure time.
Exposure to contaminants for 10 days, significantly increased total chlorophyll content, CO2 intracellular concentration, stomatal conductance and net photosynthetic rate compared to controls.
No reduction was seen in all anatomical, physiological and morphological characteristics of spinach plants exposured to contaminants for 10 days compared to the controls.
The number of stomata, proline content and antioxidant enzymes activity including catalase, ascorbate peroxidase and guaiacol peroxidase in plants exposed to contaminants for 20 days showed significant increase compared to the control plants.
Dry weight, relative water content of leaves and stomatal conductance of plants exposed to contaminants for 20 days showed a significant decrease compared to the control plants.
Plants exposed to the pollutants for 30 days, showed significant increases in antioxidant enzymes activity such as catalase, ascorbate peroxidase and guaiacol peroxidase, proline content, electrolyte leakage and the number of stomata per unit compared to controls. But total chlorophyll content, carotenoid, photosynthesis rate, stomatal conductance, chlorophyll fluorescence, relative water content of leaves, fresh weight, dry weight and length of stomata significantly decreased compared to control plants.
Stomata pores in spinach plants that were exposed to the pollutants for 30 days shrinked due to closure of stomata by the pollutants as against other exposure days and control plants.
Significant differences in the xylem and phloem of plants that had the highest and the lowest exposure time to the pollutants were not observed.

Exposure to contaminants for 10 days, significantly increased total chlorophyll content and leaf gas-exchange parameters that are most likely because of the contents in contaminants and also the role of CO2 in photosynthesis process and the presence of nitrogen and sulfur in NO2 and SO2 gases.
Between the three time of exposure in this study, the most trait changes were observed in plants exposed to pollutants for 30 days.
Significant increase in antioxidant enzymes, proline, ion leakage and number of stomata was observed in spinach plants exposed to pollutants for 30 days compared to control plants. The highest increase in this interval was related to the activity of the guaiacol peroxidase enzyme and then the amount of proline.
Among the anatomical traits, the highest change was shown in the number of stoma (62.20%) of plants exposed to pollutants for 30 days compared to controls.
Significant decrease in total chlorophyll, carotenoid, photosynthesis rate, stomatal conductance, chlorophyll fluorescence, relative water content of leaves, fresh weight, dry weight and length of stomata in spinach plants exposured for 30 days was observed compared to control plants.
The highest decrease in plants exposed to pollutants for 30 days compared to controls was observed in stomatal conductance (39.21%) and the lowest reduction was observed in the amount of chlorophyll fluorescence (2.56%).
The results showed that the exposure of spinach plants to pollutants, especially 30-days exposure, caused morphological, physiological and anatomical reactions due to contaminants that could be considered these reactions as the adaptation of these plants to the stress of contamination, in order to adapt or to deal with stress conditions and thus to survive the plant under pollution stress conditions.

An experiment was condacted To study the allelopathic effect of saffron genotyps on bindweed in the department of agronomy and plant breeding of Isfahan University of Technology, Iran in 2012-2013. Experiment was arrange as a factorial in a completely randomized desiggn with three replication. Factors included 20 saffron genotypes obtained from different regions in Iran, ( Hamedan, Nishapur1, Nishapur2, Nishapur3, Nishapur4, Sabzevar, Mashhad1, Mashhad2, Natanz, Khaf, Khorasan, Torbatejam, Kashan, Gonabad, Torbat heydaryeh, Birjand, Yazd, Shiraz, Isfahan, Kashmar) and Aquous extracts were prepared from aerial parts of these saffron genotypes in concentrations of 0, 3, 6, 12.5, 25, 50 and 100%. Seedling traits of the attributes of Bindweed (as a target species) including radicle and plumule lengthes, radicale and plumule fresh weights, plumule dry weight, germination percent and velocity were measured.. Results showed that the effect of genotype and extract concentration and their interaction on measured traits were significant. Saffron genotypes had a different effect on the triats of bindweed. Genotypes "Khaf and Nishapur3" were proven to be the most allelopathic genotype, and genotypes "Kashan, Torbate jam and Gonabad" were found to leave minimal allelopatic effects on the target species. With increasing in aquous extracts concentration traits of target specie decreased, but the effect was diffreent. Maximum inhibition was observed in aquous extract concentrations of 100% and minimum inhibition was observed at aquous extract concentrations of 3% .

Drought stress as the most important abiotic stress plays an important role in yield reduction of crops worldwide. Considering the extends and problems caused by the moisture stress, agronomic and breeding strategies in reducing yield loss are essential. In this regard, the identification and selection of effective characteristics of wheat under drought stress in increasing yield, is essential. Determining the most important morphological characteristics affecting wheat yield under stress, in order to achieve the criteria for selection to improve the performance of this plant always has been important in breeding programs. Due to the variation in drought tolerance in wheat genotypes, it is necessary for efficient water usage in each region, cultivars with higher performance and better compatibility under lower irrigation requirement should be determined for efficient water use particularly in regions with scarce water resources. Improvement of a complex trait such as yield possessing low heritability, requires indirect selection using simpler traits viz morph-physiological traits.
This study was conducted to evaluate the effects of water stress on the agronomic and morphological traits of 169 recombinant inbred lines (RILs) in wheat (Triticum aestivum L.), using two separate lattice design (drought and control) at Research Farm of Isfahan University of Technology in 2011-2012. Recombinant inbred lines of wheat were obtained from the International Center for Wheat and Maize Improvement (CIMMYT) in Mexico. The recombinant inbred lines used in this study were derived from a cross between two Seri M82 and Babax parents after being selfed for 8 generations (F9). Seeds of each line were planted in a three meter row with a row distance of 30 cm. Irrigation, fertilization and control weeds in the experimental was conducted and to provide plant requirement N, based on soil analysis, urea fertilizer at the rate of 100 kg per hectare in two stages of growth were added to the ground in early spring. Two moisture regimes of 70 and 130 mm evaporation from evaporation pan class A (16% and 20% moisture by weight of soil, respectively) were employed, and soil moisture was measured during two irrigation treatments. In both experiments normal irrigation was conducted till middle of jointing stage, and were irrigated afterward based on class of the evaporation pan.
Drought stress significantly reduced days to heading, days to pollination, days to maturity, spike length, plant height, the number of spikes per m2, the number of grains per spike, grain weight in the spike, 1000-grain weight, biological yield, grain yield and harvest index. Results of analysis of variance revealed significant differences among lines for all studied traits under normal conditions with the exception of number of grains per spike, grain weight in the spike, spike length, days to pollination and days to maturity. Under moisture stress conditions, the RILs significantly varied between the studied traits with the exception of number of grains per spike, 1000-grain weight and spike length. The correlation coefficients in the normal conditions showed that all traits had a positively correlated with grain yield with the exception of spike length and days to pollination. Under the moisture stress conditions the grain yield was correlated with all traits positively. The results of the factor analysis in both normal and stress moisture conditions showed that the measured traits have appeared either in a hidden factors which explained 67.09% and 84.26% of the total variation of the yield, respectively. Using three dimensional profiles, lines 4, 27 and 40 as the superior genotypes were introduced in terms of three factors. Based on the Fernandez’s drought tolerance index lines 1 and 69 were identified as the most drought tolerant and the most drought sensitive ones, respectively. The results of stepwise regression on the grain yield under normal and moisture-stress conditions revealed that the number of spikes per m2 and the grain weight in spike contributed 95% of the grain yield variations in both environmental conditions.
The results showed significant effects of drought on crop yield, morphological and phenological (days to maturity, days to pollination and days to heading), and only on the number of grains per plant, grain weight and spike were not significant. Therefore, in spite of inheritance variation in the studied lines supported by their effects from the environmental conditions. Also, considering the high heritability of these traits, it was concluded that these traits were less affected by the environment. Under normal compared to water stress conditions, the narrow-sense heritability of harvest index was lower. In normal conditions, the highest narrow-sense heritability belonged to the number of spike per m² (77%), but under water stress conditions, belonged to the grain yield (84%). According to the results, it can be concluded that the number of spikes per m2 and the grain weight in spike have been the two most important components of gain yield under both normal and drought stress conditions. Moreover, the superior drought tolerance lines have the potential to improve the grain yield in both environmental conditions in the breeding programs.

Excessive application of P fertilizers, use of the bicarbonated water sources for irrigation concomitant to a low level of organic matter have resulted in widespread iron deficiencies in crop plants in Iran. One of the strategies to overcome this problem is to select tolerant genotypes to iron deficiency (i.e. iron-use-efficient genotypes) or bred genotypes with high-micronutrient-uptake ability. Therefore, this experiment was conducted to study the behavior of twelve Iranian rice landraces and improved genotypes to iron deficiency (Tarom Mahalli, Amol 2, Musa-Tarom, Gharib, Shiroudi, Bejar, Neda, Nogouran, Jozdan, Sazandegi, Zayande Roud, and Kouhrang) as exposed to two levels of chelated iron fertilizers, including 5mM (iron deficiency) and 50mM (no iron deficiency) in Yushida nutrient solution culture. A factorial experiment based on a completely randomized design with four replicates was carried out in Soilless Culture Center at Isfahan University of Technology, Isfahan, Iran in 2013. The results showed that the iron content, shoot and root dry weights, total dry weight, leaf area, root length and volume and the number of tillers were significantly affected by genotypes, iron fertilizer, and their interaction. The mean dry weights were 0.215, 0.138, and 0.255 g per plant in northern landraces, northern improved, and central Iranian genotypes under no iron deficiency condition, but they were decreased by 25.7, 35.2, and 23.0% under iron deficiency condition, respectively. Based on the magnitude of decrease of total biomass under iron deficiency condition, genotypes such as Musa-Tarom, Bejar, and Zayande Roud seemed to be more tolerant in comparison to Jozdan, Amol 2, and Shiroudi.

Plane tree is one of the major tree used in urban landscapes of Iran. One of its serious problem is chlorosis and leaf abscission in many parts of the country. The current investigation was conducted to evaluate the effect of inoculation of plane trees (Platanus orientalis L.) with mycorrhizal fungus on response of plane trees in two years (2011 and 2012). An open field experiment conducted based on a randomized complete block design with 4 treatments and 6 replicates in Isfahan University of Technology. Treatments were as follwoings: livestock manure¡ chemical complete fertilizer¡ manure fertilizer mycorrhiza fungi and control (no fertilizer). The results showed that inoculation of plane trees with mycorrhizal fungus caused singnificant increase in most growth and physiological indices such as growth of current season shoots¡ total soluble sugar content¡ chlorophyll content¡ photosythetic indices and stomatal pattern ( diameter and number of open stomata).¡ To sum up the results revealed that inocultion of plants with mycorrhizal fungus¡ improved plants growth accordingly through its positive influence on stomata behavior¡ chlorophyll content and subsequently increase in photosynthesis.

Intercropping is one of the effective components of sustainable agriculture. In order to assess the effects of nitrogen application and planting arrangement on linseed and berseem clover leaf area, light absorption and their yield an experiment was conducted as a split plot based on randomized complete block design with three replications at the Research Farm of College of Agriculture, Isfahan University of Technology in 2012. The main plots included three nitrogen rates (0, 30 and 60 kg/ha of nitrogen) and subplots were different planting arrangement of linseed and berseem clover (monoculture of linseed, 70% linseed: 70% berseem clover, 70% linseed: 50% berseem clover, 50% linseed: 50% berseem clover, 50% linseed: 70% berseem clover, monoculture of berseem clover). The highest weed dry weight (286 g/m2) was obtained in monocultures of linseed when 60 kg/ha nitrogen was applied. The highest percentage of light absorption (85.3%) was achieved at different planting arrangements with application of 30 kg/ha nitrogen. The highest seed yield of linseed (53.19 g/m2) and berseem clover (72.6 g/m2) were obtained in monocultures and 0 and 30 kg/ha nitrogen treatments, respectively. In general, linseed and berseem clover intercropping with application of 30 kg/ha nitrogen were proven beneficial as they led to the greater yield and successful weed control.

In order to assess the genetic variation in Stachys accessions, an experiment was carried out in randomized block design with three replicates on 41 accessions including Ferydoonshahr (1), Damaneh (21), Gavkhoft (15), Semirom (4). According to analysis of variance significant differences were observed among all studied traits but not significant differences were observed among replications. Damaneh 20 had the highest amount of essential oil (3.37 %) and Damaneh 17 possessed the lowest essential oil content (0.092 %). According to factor analysis, the first factor explained 26 % of variation. Wet weight, plant height and number of floret showed the highest values in this factor. Number of leaves in main branch and number of leaves in lateral branch had the highest value in the second Eigen. Cluster analysis classified 41 accessions in five major groups and they revealed high differences in wet weight, dry weight, day to flowering, days to fruit set, number of floret and essential oil yield. Finally, it would be possible to cross the elite genotypes from different clusters and select the best ones in order to introduce new cultivars with appreciable agronomic traits and the highest essential oil yield.

This pot experiment was conducted to investigate the effects of ordinary and nano forms of zinc oxide on growth and ion content of four wheat cultivars (Niknejad, Iniya, Rowshan and Moghan2) under three salinity levels (0, 75 and 150 mM NaCl). In this experiment, shoot and root dry weight, and concentration of potassium, sodium and zinc in shoots were measured. Results showed that with an increase in salinity level, the shoot and root dry weight and concentration of potassium and zinc in shoot was decreased, but shoot/root dry weight ratio, sodium concentration and sodium/potassium ratio in shoots were increased. Plants provided with nano zinc oxide had higher concentration of zinc, as compared to the ordinary form of zinc oxide. Significant reduction of sodium/potassium ratio in shoots occurred due to plant nutrition of nano zinc oxide. As a result of application of nano zinc oxide, shoot dry weight was increased in Niknejad and Iniya wheat cultivars, but it was decreased in Rowshan and Moghan2 cultivars. The results of this experiment showed that there was significant variation among wheat cultivars in response to the application of nano zinc oxide.

The Karyotype analysis was performed on 46 wheat accessions belonging to five species (Triticum monococcum، T. urartu، T. durum، T. turgidum and T. aestivum) and two subspecies (T. boeoticum subsp. thaodar and T. boeoticum subsp. boeoticum) carrying A genome. All chromosomal sizes were measured with computer-aided program Micro Measure 3. 3. Software. RL، TCL، MCL، arm ratio، centromeric index، TF%، mean of long and short arms، AsI%، S%، DRL، A1، A2 and karyotype formula were calculated for each chromosome. All the accessions were placed in 1A category of stebbines asymmetry categories. The scatter diagram based on A1 and A2 constructed three groups of karyotype asymmetry in the accessions studied: 1- T. aestivum with the highest asymmetrical karyotype، 2- T. monococcum، T. boeoticum subsp. thaodar and T. boeoticum subsp. boeoticum with the lowest asymmetrical karyotype and 3- T. urartu، T. turgidum and T. durum being with an intermediate between the two previous groups. T. monococcum based on the A1 and A2 index (asymmetric index) had the oldest and the most primitive karyotype among diploid species. According to the results، it might be suggested that T. durum is more primitive than T. turgidum and T. monococcum could be considered as a donor of A genome to T. durum and T. aestivum.

In order to evaluate endophyte effect on plant earliness, compatible host-endophyte combinations including four genotypes of tall fescue and two genotypes of meadow fescue were selected and used in this study. One tiller-part of each genotype was treated using a fungicide mixture of Propiconazole and Folicur. New tillers of endophyte-infected and endophyte-free plants were planted in the field according to a complete block design with three replications. The traits including days to head emergence, days to 50% anthesis, days to maturity initiation, number of heads (as a weekly measurement), total seed weight, net seed weight and empty seed weigh were measured. Results showed that endophytes can enhance head emergence, maturity initiation and periodical seed yield. Days to 50% anthesis, and days to maturity initiation were also reduced. Head numbers in some genotypes increased up to 2 times. Increase in net seed yield may show some physiological alterations in plant such as hormonal balance alteration which may provide better seed setting in infected plants. Based on this study, we concluded that endophytic fungi can induce earliness in infected host plants.

A major limitation for higher yield of rice plant is water availability. Water use efficient varieties tolerant to upland conditions could help to relax this limitation. Three separate experiments were conducted to study the effects of water regimes on growth, aerenchyma formation, and nutrient absorption of Iranian rice varieties. In the first experiment, five varieties of rice were grown under three different irrigation levels. The second experiment involved the study of nutrient uptake by Sazandagee and Tarom varieties under four different water regimes, and in the third experiment, the effect of aeration on growth characteristics of Sazandagee rice was assessed in a hydroponics system. Results of the first experiment showed that submerged conditions continuously or after four weeks of initial growth had a significant effect on plant growth. Aerenchyma formation was affected by rice varieties and was less affected by irrigation status. In the second experiment, plant growth characteristics were affected similar to experiment one. Also it was shown that nutrients such as P, Mg, and Fe were absorbed with higher efficiency under submerged conditions. Results of the third experiment revealed that aeration had no significant effect on plant growth characteristics. Based on the results of these three experiments, it can be concluded that better performance of rice plant under continuous or partial flooding is mainly related to higher absorption of some macro - and micronutrients. Therefore, this parameter should be considered in water management programs for rice.