مجله پژوهشهای گیاهی (زیست شناسی ایران)
سال سی و دوم شماره 2 (تابستان 1398)

One of the strategies used to reduce the negative effects of various stresses on plants is the application of growth regulators such as salicylic acid. This study investigated the interaction between salicylic acid (0, 0.5 and 1 mM) and cadmium chloride (0, 100, 200 and 300 µM) on growth traits, photosynthetic pigments, antioxidant enzymes activity, relative water content, proline and glucose content in wheat seedlings. The results showed that cadmium stress reduced growth treats of plants from 30 to 50 percent compared to control untreated plants, significantly. Moreover, relative water content decreased by 7% and the chlorophylls a and b levels were about 2 times lower. Cadmium stress caused a three-fold increase in the activity of catalase and superoxide dismutase enzymes and also glucose levels dropped by 2 times. Salicylic acid spray had significant positive effects on growth traits of cadmium-stressed seedlings and between 20% to 60% increased these parameters. The relative water content of these seedlings also increased 2 times. Salicylic acid has increased the activity of antioxidant enzymes and increased levels of chlorophyll and glucose by over 40% compared to control plants. The results of this study showed that salicylic acid is effective in reducing the negative effects of cadmium stress by increasing the amount of chlorophyll, improving the activity of antioxidant enzymes and changing the amount of glucose in Wheat.

Biodiversity is recognized as one of the main criteria of sustainable tourism management. In addition, forest-based recreation is one of the most important activities in nature –based tourism. Consider these two issues together will provide a significant contribution to the forest management. This study conducted to understand the impacts of nature–based tourism on the structure and biodiversity of Arasbaran forest. Sampling was carried out by using of 60 circular sampling plots (1000 m2) and systematic-random sampling method in two recreational and non-recreational areas. Forest structural characteristics (density, basal area and canopy coverage), biodiversity indices (Shannon-Weiner, Simpson, richness and evenness) and species importance value index (SIV) were calculated. The results showed that there was significant difference between the study areas in terms of Shannon-Wiener, Simpson and species richness indices, while there was no significant difference between two regions in terms of evenness and forest structural characteristics (p≤ 0.01). The value of SIV showed that Acer campestre L. was the most important tree species in the recreational and non-recreational regions and followed by Carpinus betulus L. in non-recreational region. Based on the results of the present study, nature–based tourism in the forest area did not have a significant effect on the tree layer structure, but showed significant effects on biodiversity indices. This result emphasizes the sensitivity of biodiversity in forest ecosystems.

Contamination of soils with oxide metals nanoparticles, by various human activities, is an important environmental issue in both developing and developed countries. The aim of the present study was to investigate the effects of ZnO and CeO2 NPs (250, 500, 1000 and 2000 mg L-1) on some growth and biochemical parameters of bean plants growing under greenhouse conditions in a completely randomized design. The results indicated that ZnO NPs almost, at all concentrations, enhanced plant height, while CeO2 NPs at high concentration did not. Both NPs at all concentrations decreased chlorophyll and anthocyanin content in the experimental plants compared to control ones. There was no significant differences in total protein content in both treatments compared to control. However, a protein band with molecular weight of 28 KDa seems to be appeared in the group treated by 500 mg L-1 ZnO NPs. The activity of antioxidant enzymes in CeO2 NPs-treated plant was higher than those in ZnO NPs treatments. Altogether, the results showed that plant responses to CeO2 NPs were more subject to change upon to concentration than ZnO NPs.

In this study, the effect of calcium nutrition with two sources of calcium chloride and nano-calcium chelated on vegetative, reproductive and postharvest life of tuberose (Polianthes tuberosa L.) was investigated. The experiment was a completely randomized design with 5 treatments and 4 replications. Treatments included calcium chloride with two concentrations of 1.5 and 3%, nano-calcium chelated of 2 and 4 ml L-1 with control (distilled water). By planting of bulbs and reaching the plants to 10 to 12 leaves, the spray of two sources of calcium was started and repeated every 4 days to 5 times. The results showed that both calcium sources had positive effects on some of the properties mentioned in tuberose, and the effect of nano-calcium chelated was better in most traits than calcium chloride. The highest leaves fresh and dry weights, leaf area, fresh and dry weights of bulblets and root, and also leaf number, length, diameter, number of florets, fresh weight and postharvest life of flowering stem and were obtained with 4 ml L-1 nano-calcium chelated spraying. The fresh and dry weights of mother bulbs did not significantly affected by the nutrition of both sources of calcium and also the highest number of bulblets were observed in the control treatment (without calcium spraying).

Pistachio seeds have irregular and low percentage germination due to dormancy, which causes the next growth of seedlings to be difficult. The purpose of this experiment was to investigate the influence of different concentrations of plant growth regulators (Gibberellic acid and Benzyladenine) on seed dormancy breaking and germination of pistachio Cv. ‘Badami Rize Zarand’. This experiment was carried out as a completely randomized design with 10 treatments and 30 replicates in condition of greenhouse. Results showed that different concentrations of plant growth regulators had a significant difference on all parameters investigated (P<0.01), as the treatment of 100 ppm GA3 in combination with 100 ppm BA resulting in the greatest seed germination percentage (100%), germination rate (0.76 seeds per day), shoot length (33.33 cm), root length (76 cm), root volume (7.83 cm3), shoot fresh weight (31 g), root fresh weight (15.16 g), shoot dry weight (11.52) and root dry weight (3.83). Nevertheless, the highest content of chlorophyll a (14.43 mg/g fresh weight), chlorophyll b (8.63 mg/g fresh weight) and total chlorophyll (23.06 mg/g fresh weight) was related to the treatment of 0 ppm GA3 in combination with 100 ppm BA.

The formation of the seed is part of the process of reproduction in seed plants. The study of the ontogeny of endosperm and embryogenesis was considered in current research using microscopic techniques. The samples were collected from different developmental stages. Then, the fixed samples were studied by different histochemical methods. The observations indicated that the ovule was of the anatropous and bitegmic type. The outer layers were removed in the early stages. Thus, the seeds of Z. fabago were categorized of testal type. During the early developmental stages, the endosperm was of nuclear type and then changed into the cellular type. This makes it easier for the embryo to connect with endosperm tissue in early stages. The endosperm develops gradually toward the central spaces and occupies the entire space of the embryo sac. In fact, the endosperm tissue remains until mature embryo stage and was not degenerated. Also globular, heart-shaped, torpedo-shaped and mature embryo stages along with the RAM, hypocotyl, and SAM were observed. Cytochemical tests indicated that in the later stage of seed development, the formation of starch grains and the strongly thickening of cell walls were occurred, causing considerable reduction of cell cavities as well as hardening of this tissue. In the other hand, the cell storage in the endosperm tissue was more lipid-based than proteinaceous compounds. But in mature embryo no carbohydrate was detected.

The presence of heavy metals pollution in agricultural soil and its products, one of the most important ecological problems in the world. Refinery gas pollutants in the region, is one of these resources through the air, waste and other methods can be contaminated. In order to determine the amount of heavy metals in surface and hock (Malva Silvestris) Soil samples Bidboland and evaluation of refinery pollution levels, with 54 surface soil samples and 30 samples were collected and the amount of heavy elements hock (Malva Silvestris) cadmium, mercury, vanadium, lead, chrome and arsenic using atomic absorption spectrometry (ICP) were analyzed. The results of analysis of soil samples The average value of the metal, mercury and arsenic, while the lowest was recorded for cadmium and vanadium. The maximum coefficient of variation of lead in any case, the concentration of heavy metals in soil samples from the process following cl aim As> Hg> Cr> Pb> V> Cd. Comparing these results with international standards shale shows that the concentration of Elementsin the study area is less than standard. The plant, for example, the highest average value of the metal to hock, for cadmium (ppm 2/46) to the East, and the lowest mercury (ppm 0/47), and chromium (ppm 0/61) both for North was recorded. In any case, the concentration of heavy metals in plant samples follow the process below: Cd> As> Pb> Hg> va> Cr. Also the highest concentration of biological index related to the element cadmium (3/09-3/98) and the lowest in chrome (0/66-1/69) respectively.

Previous studies have shown that sodium nitroprusside (SNP) plays an important role in the response of plants subjected to salt stress. Therefore an experiment was conducted during 2015 in controlled condition to investigate the impact of exogenous sodium nitroprusside on the growth, morpho- physiological traits and antioxidant activity of canola plants (Brassica napus L.cv.Modena) grown under salinity stress. Different concentrations of sodium nitroprusside (SNP) contains: 0, 100 and 200 µM, were applied on canola plants exposed to different levels of salinity (0, 120 and 240 mM Nacl), so experiment was conducted as a factorial based on completely random design with three replications. The result showed that salinity decreased fresh and dry weight and had a significant increase in proline and hydrogen peroxide content and superoxide dismutase activity, but had no significant effect on photosynthetic pigments content and Ascorbate peroxidase activity. SNP had a significant increase on fresh weight, dry weight, chlorophyll b and proline content in 120 mM of salinity. H2O2 content and antioxidant enzymes activity of plants under salt stress significantly reduced (P <0.05). Finally results showed that SNP significantly improved salinity tolerance of canola plants.

Box tree (Buxus hyrcana Pojark.), is an ornamental tree and shrub species that has application in various industries. Growth and development of box tree is very slow, its rooting is hard and is under danger of extinction. Thus, the purpose of this research was investigation of the effect of different concentrations of BAP and IBA (0, 0.5, 1, 1.5 and 2 mg l-1 form each two) on micropropagation of box tree. The experiment was carried out as factorial based on a randomized complete block design in four replications. Results of the present research showed that the largest number of shoots (6.200/plantlet) was obtained in apical buds expalnts treated with 1 mg/L BAP along with 0.5 mg/L IBA. Apical bud explants were produced the maximum node number (4.100/plantlet) in medium containing 1 mg/L BAP and the largest number of leaf (with average of 6.566/plantlet) along with 1.5 mg/L IBA. Also, the largest number of root (6.466/plantlet) was calculated in explants treated with 1 mg/L BAP plus 1.5 mg/L IBA. Plantlets were transferred to pots containing peat and perlite with ratio of 1:1 for acclimatization. The pots were kept in a greenhouse with temperature of 24-26ºC and relative humidity of 70% and periodic irrigation. Around 90% of those were healthy. These acclimatized plantlets were similar to mother plants.

Narcissus tazetta L. of the Liliaceae family, despite the high demand market has very slow vegetative propagation. For the rapid propagation, in this study micropropagation of Narcissus under different hormones and soil transfer of plantlets was investigated. Micropropagation of this plant was done in three procedures: induction, proliferation and bulb production from explants. It was found that the best medium for shoot induction is modifiedMS+ 4 mg l-1 BAP +0.12 mg l-1 NAA and shoot clumps which were cultured on the MS+2 mg l-1 BAP +0.12 mg l-1 NAA medium, showed the most proliferation. Transferring these shoot clumps to MS+ 9% sucrose + 0.1 mg l-1 NAA medium resulted in maximum bulbs production. After 4 months, the bulbs were 12–20 mm in diameter. In this medium, roots were thicker and shorter than the ones grown without NAA. The bulbous plants treated with salicylic acid and transferred to soil and then treated with Carbendazim fungicide. Carbendazim increased survival percent (100%) but salicylic acid did not have any effect on success of transferring to soil. The high number of bulbs and high percentage of survival of regenerated plants in soil indicated that micropropagation is an effective alternative method compare to traditional method.

This experiment had been carried out to evaluate the potential of mycorrhiza fungus on growth rate and performance of plantlets derived minituber in water deficiency condition. The test was conducted in a factorial experiment based on completely randomized design with four replications. The factors included four level irrigation regimes (100%, 85%, 75% and 65% of water field capacity), inoculation of potato minituber by mycorrhiza sp. Glomus intraradices and non-inoculated ones. Growth indices such as stem length and diameter, internode number and length, stem and root fresh weight, leaf area and chlorophyll content were measured. Analysis of variance showed that the main effect of mycorrhiza and water irrigation regimes had significant effect by probability of 1% α level on stem length, leaf area, chlorophyll content, colonization percentage, fresh and dry stem weight, fresh and dry root weight and number of minituber. Interaction effect of two factors was significant only in leaf area, chlorophyll content and dry root weight. By mean comparisons demonstrated that the highest internode and stem length, fresh and dry stem weight, fresh root weight, leaf area and chlorophyll content were accomplished in mycorrhizal inoculation with 85% FC providing water. Totally, the results demonstrated that mycorrhization of minituber in two lower water available levels produce plantlets that had same situations as compared with non-inoculated of 100% FC providing water.

The biotic interactions have the strong impact on the ecosystem function. This study aims on the investigation of biotic interactions influenced by shrub death in two exposures. Therefore, 20 alive and 20 dead Onobrychis cornuta cushions were selected in each exposure and for each of the plots one plot with the same size in open space were selected (in total 160 plots) and their plant species were recorded. In order to determine the main effects, GLMM were applied and T test were used to compare mean between shrub health and exposures. Our results showed that under alive and dead shrubs, perennial herbs (2.8 and 6.35 %) and shrubs (0.6 and 3.25 %) were significantly reduced, respectively. In the southern exposure, total cover of species (17.55 and 6.85), perennial grasses (1.70, 5.98), perennial herbs (2.38, 5.28) and shrubs (1.18, 3.40) were declined under dead shrubs respectively. GLMM results showed that shrub health has the strongest effects (F=21.25; P<0.009) on RII. In the southern exposure, competition was higher under dead shrubs (-0.58) than alive shrubs (-0.14). Exposure had strongest effects on the perennial grasses (F=551.47; P<0.0001) which in both dead and alive shrubs the cover in the northern exposure is higher than southern exposure. Shrub health has highest effects on perennial herbs (F=7.22; P<0.009) and in the northern exposure shrub death (- 0.36) reduced RII significantly compare to alive shrubs (- 0.004).

In order to build middle Asia collection in the Mashhad Botanical Garden, some plants such as Cotoneaster were produced by seed. Cotoneaster nummularioides Pojark fruits were collected from kopet dag highlands mountainous region in northeastern Khorasan Razavi. The seeds were performed on 25 treatments in a factorial randomized complete block design with three replications. In this study the effect of different chilling and different scarified treatments was investigated. Studied treatments zero (control), 1, 2, 3 and 4 months cold stratification and chemical scarification, including without scarification (control), hydrochloric acid, hydrochloric acid - Potassium nitrate, sulfuric acid and sulfuric acid - Potassium nitrate. After the end of the treatments, the seeds were sown in a greenhouse in bed of coco peat – perlite. The results showed that there was significant difference (P<0.01) among the studied treatments and sulfuric acid - Potassium nitrate with 4 months cold stratification had had the highest average germination (18.3 percent). In controls, chilling in 1 and 2 and 3 month without scarification and chilling 1 month with scarification treatments; no germination was observed. The problem dormancy Cotoneaster resolved under the combined effects of scratches Shell and cold stratification, As a result, the physical and physiological factors influence the dormancy of this species.

Weed control in crop lands using herbicide raised several concerns for human health and environment. Decomposition of some plants residues leave special compounds in the soil which may prevent weed emergence and prohibit the use of herbicides for weed control. In order to non-chemical weed management and investigation of the sweet corn response to wheat and rye residues (low, medium and high) a field experiment was conducted using RCBD. Results showed that wheat straw was more beneficent than rye in weed control and increasing the sweet corn yield, meanwhile wheat in low residue treatment was more effective than others. Indeed this treatment produced the highest leaf area index (7) and fresh forage yield of the crop (24693 kg.ha-1). The highest (2251.3 kg/ha) and the lowest (1653.8 kg/ha) amount of kernel yield were obtained under low wheat residue and low rye residue treatments respectively with +22% and -6.2% change from control treatment. Therefore it should be stated that sweet corn planting after wheat rotation will confront to less weed (density and biomass) due to allopathic effects of low wheat residue which indirectly increased sweet corn economical yield.

The result of floristic and ecological research about 48 species from families of Papaveraceae, Fumariaceae, Solanaceae, Amaranthaceae, Alliaceae, Boraginaceae, Geraniaceae and Malvaceae in interior confine of Hamedan city which researched during few past years showing most of observed species of this families are just segetal and ruderal hemerochor elements which mostly are indicator of the urban environments and most of them do not see outside of urban environments or rarely seen in a few region and in a few number. Therefore, most of observed wild plant species which collected from margin of streets, beside of trees, gardens, farms, unbound farms, rains, parks and other interior urban environments are including non-indigenous elements which usually growing in the urban natures. In this case, to recognize the urban nature as well as its biological species and city as an unstable and unique ecosystem is so important and now days have the valuable researchable and environmental importance in which urban biotopes can not consider unimportant and should not rely on suburban researches.

In order to evaluate the effects of ultrasound intensity (20-30, 40 kHz) and ultrasound exposure time (2- 4- 6 and 8 minutes) on germination, physiological and morphological characteristics of sesame, two separate experiments were performed in laboratory and research greenhouse of Shahrood University of Technology. The trials arranged in a factorial experiment based on a randomized complete block design with four replications. In the first experiment, germination percentage, the speed of germination, mean germination time, mean day germination, seed vigor index, root and shoot length, the coefficient of uniformity of germination, abnormal seedling percentage and some physiological characteristics including the activity of catalase and superoxide dismutase enzymes were evaluated. In the second experiment, emergence percentage, speed of emergence and morphological characteristics including plant height, leaf number and leaf area, root length, root to shoot ratio and total biomass were measured. Based on results, ultrasound exposure time had significant effects on all studied characteristics in both experiments, so that the highest and lowest mean value was related to the 8 and 2 minute respectively. Ultrasound intensity significantly influenced most of the studied characteristics and the highest and lowest mean was obtained at 40 and 20 kHz respectively. The interaction of ultrasound intensity and ultrasound exposure time were significant on most of traits. According to the results, it can be concluded that the use of ultrasound irradiation could greatly improve the germination, morphological and physiological characteristics of sesame.

Thymus kotschyanus Boiss.& Hohen. is an Iranian medicinal plants that grows in different areas of Iran such as Mazandaran, Gilan, Azerbaijan, Kurdistan and Tehran. In this study, variation in the quantity and quality of the essential oil of Thymus kotschyanus Boiss.& Hohen. apical shoots at different developmental stages including vegetative, early flower opening and full flowering stages is reported. The obtained oils by hydro distillation of dried samples were analyzed by GC and GC/MS. The maximum percentage of oil was in full flowering stage (3.5%). 21, 25 and 19 compounds were identified in the oils of apical shoots in vegetative, early flower opening and full flowering plants, respectively. The major components of the branches essential oils were similar in all stages which included carvacrol, sabinene hydrate, 1,8-cineole, p-cymene and borneol. Results showed that the essential oil of T. kotschyanus apical shoots were rich in monoterpenes (19 compoiunds). 95.48%, 95.26% and 90.69% of the total identified compounds were monoterpens in vegetative, early flower opening and full flowering stages, respectively.

For investigation the impact of drought stress on several Agronomic, physiological, yield and yield component in various varieties of medicinal pumpkin (Cucurbita pepo L.), an experiment was conducted as a factorial based on complete randomized block design with three replications at Agricultural and Natural Resources Research Center of Zanjan during spring and summer of 2015. The effects of water stress in five levels ( S1 or control, S2 or irrigation in 75% of Field Capacity (FC), S3 or irrigation in 50% FC, S4 or irrigation in 25% FC and S5 or without irrigation (dry farming )) and four varieties that cultured in multiple points of Iran ( V1 or unknown variety from khoy, V2 or unknown variety from Isfahan, V3 or unknown variety from Zanjan and V4 or var. Styriaca) were considered. The results showed that the effects of drought stress on traits was significant and cause decrease in all investigated parameters. However, the highest grain and fruit yield were obtained in control treatment or full irrigation in Styriaca variety with 825 and 15430 kg.ha-1, respectively and lowest were obtained from Isfahan variety in dry farming condition with 680 and 2758 kg.ha-1 respectively. In the presence of moderate drought stress, the highest rate of photosynthesis, transpiration, stomatal conductance and relative water content was for Isfahan unknown variety and seems that it is a good candidate variety for areas with mild stress.

Present study aimed to enhance resistance to drought stress Calotrope Seedlings Using AMF is conducted under greenhouse conditions for six months. So an experiment with two levels of inoculum (Control and AMF) and six levels of water stress (3, 6, 9, 12, 15 and 18 days irrigation interval) as a factorial experiment in a completely randomized design with three replications was formed. The highest percentage of mycorrhizal colonization in seedlings under drought 3 days was showed at a rate of 43 percent. The rate of photosynthesis and transpiration in plants 9.06 and 0.35 respectively that with increasing intensity of drought has resulted in a reduction parameters. N concentration in leaves and roots of the seedlings were inoculated and control showed significant differences in stress levels. Water use efficiency amount is 0.55 under drought stress 6-day mycorrhizal fungi inoculation was observed. Results of this study indicated that, with regard to the role of Arbuscular mycorrhizal fungi in Enhance and facilitate the uptake of water and elements of the nutritional, increasing the volume of the roots, creating root colonization and improvement of physiological variables interval of drought to 9 days.

In present study, effects of foliar of NPK fertilizer on some physiological, morphological parameters and essential oil of medicinal plant of savory (Satureja hortensis L.) were studied. Experimental design was Randomized Complete Block design (RCB) with 4 treatment and 3 replications. Treatments were including control and foliar of NPK fertilizer with proportions of 20-20-20, 10-50-10 and 12-12-36. Highest number of leaves, lateral branches, height and wet and dry weight of roots and shoots was obtained by fertilizer treatment with ratio of 12-12-36. It seems that eminent role of potassium rather than nitrogen and phosphorus in fertilizer composition of 12-12-36 could lead to significant increases in these traits. The highest content of chlorophyll a with 0.161 mg g-1 F.W and the highest rate of carotenoid with 0.571 mg g-1 F.W were captured in fertilizer with ratio of 20-20-20. Control treatment revealed the most content of anthocyanin with 37.682 mg g-1 F.W. Low levels of anthocyanin in foliar application treatments in comparison with control sample may be because of creation the optimum condition for plants by application of fertilizer. Total essential oil content demonstrated fluctuations in different treatments so in plants with fertilizer treatments with ratio of 12-12-36 had the most essential oil productions rather than control and other fertilizer treatments. Outcomes of regression analysis by stepwise method showed that chlorophyll a, number of leaf and height had the most effect on dry weight of stem and could justify 85% of dry weight of stem.