جستجوی مقالات مرتبط با کلیدواژه « فیزیولوژی » در نشریات گروه « زراعت »

This research was carried out with the aim of investigating the effect of Biofertilizers on some characteristics of guar in the crop year of 2018-2019 in Iranshahr city.

The research was carried out in the form of a randomized complete block design with 8 treatments and 4 replications. The treatments included 1- Nitroxin (1 liter per hectare), 2- Mycorrhiza (200 kg per hectare), 3- Azotobacter (1 liter of fertilizer per 100 kg of seeds), 4- Rhizobium (1 liter of fertilizer per hectare), 5- Phosphate Barvar 2 (100 grams per hectare), 6- Phosphate Barvar 3 (100 grams per hectare), 7- Biosulfur (6 kg per hectare), and 8- control.

The results demonstrated that the effect of fertilizer type on most of the investigated characteristics was significant at the probability level of 1%. The effect of the treatments on the percentage of mucilage was significant at the five percent probability level. The highest biological yield (14.66), number of lateral branches (11.78), harvest index (31.79), plant height (166.53 cm), number of seeds per plant (52.47), seed yield (kg 4438/13 ha), seed nitrogen percentage (5.475), seed protein percentage (32.71), ash percentage (0.173), mucilage percentage (25.860) and swelling factor (1.83 ml) were obtained under the influence of the Nitroxin biofertilizer. The highest number of seeds in pod (5.17) and 1000-seed weight (35.67 g) were obtained under the effect of the biosulfur biofertilizer.

  Among the investigated treatments, the nitroxin biofertilizer and then the biosulfur exerted a relatively greater effect on most of the quantitative and qualitative characteristics of the guar plant.

Verticillium wilt disease is one of the most important damaging and limiting factors of cotton cultivation worldwide. This disease reduces the quantity and quality of the product. Due to the economic importance of Verticillium wilt cotton disease, the best way to control this disease is to use tolerant cultivars. This experiment was performed to determine the effect of disease on morphological and physiological characteristics of cotton cultivars in order to identify tolerant genotypes.

The experiment was conducted in 2020 in the greenhouse of Khorasan Razavi Agricultural Education and Natural Resources Research Center (Mashhad Plant Protection Department). Ten commercial Iranian cotton cultivars belonging to Gossypium hirsutum including Varamin, Sahel, Bakhtegan, Khorshid, Armaghan, Mehr, Koker, Khordad, Kashmar and Deltapine were planted in factories in a completely randomized design with three replications in the greenhouse. The first factor was cotton cultivars and the second factor was the contamination of cotton cultivars with fungal isolates.

The results of analysis of variance of the measured traits on the studied genotypes showed that the tested cultivars in terms of leaf number, crown diameter, number of branches, leaf area, chlorophyll index, disease severity, relative leaf water content and electrolyte leakage membranes were significantly different at the 1% probability level. This difference was not observed in terms of plant height. Comparison of the mean of the above traits (except plant height) in the treatment of contamination levels, indicated that the cotton plants  inoculated with the pathogenic fungus Verticillium wilt compared to control plants (no fungal infection) had lower number of leaves, number of branches , leaf area and crown diameter. Mean comparisons of the above traits were performed between genotypes. Some genotypes can be selected for field experiments in terms of superior study traits. The results of comparing the mean interaction of infection × cultivar for all traits (except plant height) were significant at 1% level. Under the conditions of infection, the highest severity of the disease was related to Varamin and Cocker-handard cultivars. While the lowest severity of the disease was related to Bakhtegan cultivar.

The results showed that Verticillium wilt disease reduces the number of leaves, number of branches, leaf area, crown diameter, chlorophyll index and relative water content. While this disease increases the electrolyte leakage of cell membrane. In this regard, a negative and significant phenotypic correlation was observed between disease severity and number of leaves, branch, crown diameter and chlorophyll index. There was a positive and significant phenotypic correlation between disease severity and membrane electrolyte leakage. Therefore, plants with more leaves, higher chlorophyll index and relative water content and lower electrolyte leakage are more resistant to infection.

Seedling wheat spirit are tolerant to strict dehydration up to the 4th day following imbibitions. The aim of present study is investigation of responsive proteins to drought stress and recovery in seeds attached to four day seedlings. The test was done by drought stress using interruption of irrigation in two time points (10 and 20 days) and recovery for 3 and 7 days in a growth chamber. All the experiments were conducted based on Completely Randomized Design (CRD) with three replications.Seedlings attached to seedlings were examined for physiological and protein assays. Physiological traits showed strict drought stress level on seed and recovery could return seedlings to normal condition. 2DE done on seed of all treatments and replicates and 657 protein spots were reproducibly detected by Ag No3  staining from seeds. Finally, after significance test, 130 spots were detected by searching protein data banks. Drought stress has increased the expression of genes involved in the production of defense proteins (proline increase), the breakdown ofseed storage compounds, and the production of proteins that are effective in structural changes in the cell wall. On the other hand, reduced expression of proteins effective in respiration and protein breakdown has reduced energy consumption in cells under stress. Under re-irrigation conditions, increased expression of proteins effective in carbohydrate metabolism has led to the consumption of nutrients in seeds (reduction of seed weight) and the production of new structural proteins (presence of new leaves and roots).

As medicinal plant, Aloysia citriodora (Family, Verbenaceae) is applied in nutritional and pharmacological purposes. According to the findings, many parameters relating to cultivation conditions may influence on the different factors of the herb and result in different percentage of concerned constituents. Among various stresses, salinity is a major threat to modern agriculture causing inhibition and impairment of crop growth and development. Salinity impairs plant growth and development via water stress, cytotoxicity due to excessive uptake of ions such as sodium (Na+) and chloride (Cl−), and nutritional imbalance. Additionally, salinity is typically accompanied by oxidative stress due to generation of reactive oxygen species (ROS). Finding the method to overcome this issue is of great importance. Utilization of nano technologies to increase of medicinal plant production is one of significant aims of plant efficiency, which affects plant growth processes. Nanomaterials offer a wider specific surface area to fertilizers and pesticides. In addition, nanomaterials as unique carriers of agrochemicals facilitate the site-targeted controlled delivery of nutrients with increased crop protection. Among different nano materials, application of titanium nanoparticle in agricultural and nutritional industries is suitable due to its role in conservation, increase of photosynthesis and increment of tolerance to different kinds of stresses.

In this study, the completely randomized factorial design was performed with two factors including titanium nano particle (0, 50, 100, 200, 400 ppm) and salt stress (0, 75, 159 mM of NaCl) with three replications in order to assess some of morphological and phytochemical properties of medicinal plant Aloysia citriodora L. The three months transplants were prepared from the greenhouse of the Iranian Institute of Medicinal Plant. After transferring the transplants to Sana Institute of Higher Education, they were cultivated into plastic vases containing perlit and pitmoss with light/dark period of 16/8 h, humidity percentage of 60% and temperature of 25°C. After the last treatment, the whole plant was harvested, washed and the plant height was measured by ruler. In order to measure the dry weight of shoot and root, these parts were separated and placed into paper envelope to be dried in oven at 121°C for 12 h. for calculating the wet and dry weights of shoot and root, we used the weigh machine (Sartatius) with accuracy of 0.1 g. In order to assess the physiological traits, the leaves and roots of three plants in each replication were collected conserving at -20°C. Then, the physiological properties such as chlrorophyll a, chlorophyll b, total chlorophyll, carotenoid and anthocyanin contents were measured. The analysis of variance, mean comparison, simple correlation and step-by-step regression were performed based on SAS software version 9.4.

The result showed that salt stress caused decrease of wet and dry weight of root and shoot. While, the increase trend of these traits was indicated based on titanium nanoparticle effect. The obtained result from correlation and regression analysis of the studied traits showed that the shoot dry weight had the most direct effect on shoot dry weight yield with coefficient of determination of 0.82 (R2). The mean comparison of chlorophyll contents (a, b and total) were increased by increment of titanium nanoparticle concentration. However, the chlorophyll contents were decreased by increase of salt stress levels. In addition, the interaction effect of elicitor and salt stress showed that carotenoid and anthocyanin contents were increased by 400 ppm of titanium under 75 and 150 mM of salt stress.

The purpose of this experiment was study on genetic variation of wheat mutant lines (T-67-60 and T-65-7-1) and its parent (Tabasi cultivar) using RAPD molecular marker and also compare some biochemical parameters of salinity tolerance between the mutant lines and the parent in response to salt stress in the seedling stage.In this study, two mutant lines of wheat (T-67-60 and T-65-7-1) with its parent (Tabasi cultivar), cultured in the Yoshida hydroponics at 30 °C and lighting condition (16 hours of light). Then salinity stress induced on wheat seedling at electrical conductivity 6 dS m-1 and leaf samples were collected for DNA extraction and evaluation of biochemical parameters (proline, protein and chlorophyll content).The pattern of RAPD marker showed more similarity of line mutant T-67-60 with parent (Tabasi cultivar).The results of biochemical parameters showed that mutant lines (T-67-60 and T-65-7-1) were higher tolerance than parent (Tabasi cultivar) under salinity stress.Variability of mutations induced by gamma radiation in wheat revealed and verified with molecular RAPD primers. In addition, differences in biochemical characteristics under salinity condition in the mutant lines (T-67-60 and T-65-7-1) and the parent (Tabasi) implies genetic variation for these traits.

In order to investigate the effect of drought stress on leaf area index, photosynthesis rate, chlorophyll, stomatal conductance and proline content in bean cultivars, a factorial experiment was conducted in a randomized complete block design with four replications. Treatments included drought stress in three levels, complete irrigation (control), irrigation cut at two weeks after emergence and irrigation cut at flowering stage and two bean cultivars were Talash and Khomain. Leaf area index, chlorophyll a and b, photosynthesis rate and stomatal conduction were decreased due to drought stress but amount of proline was increased. By applying drought stress at flowering time and two weeks after emergence compared to full irrigation (control), leaf area index was 30.57 and 55.96 percent, content of chlorophyll a was 23.1 and 56.05 percent and the content of chlorophyll b was 13.67 and 30.76 percent, photosynthesis rate was 13.22 and 26.73 percent, stomatal conductance was 31.65 and 50.25 percent decreased, respectively and amount of proline increased by 51.11 and 88.14 percent respectively.The highest and the lowest leaf area index were in complete irrigation (control) and Talash cultivar with 5.29 and in irrigation cuttings in two weeks after emergence and Khomain cultivar with 2.08, respectively.The highest amounts of chlorophyll a and b belonged to complete irrigation (control) and Talash cultivar with 0.213 and 0.118 mg/g fresh leaf weight and the lowest amount of chlorophyll a and b was related to irrigation cut at two weeks after emergence and Khomain cultivar with 0.132 and 0.76 mg/g leaf fresh weight, respectively. Generally, the negative effect of drought stress on chlorophyll a was more than chlorophyll b. Drought stress significantly reduced the rate of photosynthesis in bean cultivars.This decrease was observed in irrigation cut at flowering stage and irrigation cut at two weeks after emergence in comparison full irrigation (control) in the cultivar of the Talash was 12.99 and 24.50 percent respectively and in Khomain cultivar was 13.56 and 29.19 percent respectively.Stomatal conductance in complete irrigation (control), irrigation cut at flowering stage and irrigation cut at two weeks after emergence in the Talash cultivar was 0.432, 0.321 and 0.223 mol/m2.s and Khomain cultivar was 0.365, 0.233 and 0.154 mol/m2.s, respectively.The results of mean comparison showed that drought stress in each of the stages of growth reduced stomatal conductance in both cultivars. However, the percentage reduction in Khomain was more than the Talash.The content of proline in complete irrigation (control), irrigation cut at flowering stage and irrigation cut at two weeks after emergence in the Talash cultivar was 1.47, 2.30 and 2.83 mg/g fresh weight and in Khomein cultivar was 1.24, 1.78 and 2.25 mg/g fresh weight, respectively. drought stress in both cultivars increased significantly in proline content. According to the results, bean varieties had no significant difference in leaf area index and chlorophyll b content. In drought stress condition, Talash cultivar compared with Khomain cultivar showed less decrease in stomatal conductance and leaf area index and more had chlorophyll content and photosynthesis rate and it is recommended to cultivate in areas with drought stress.

In order to study the effect of foliar application of different levels of methanol on yield and physiological traits of two dry-land wheat varieties, an experiment was conducted as factorial based on completely randomized block design in 2014-2015 in Khorram Abad climate conditions in research farm of Khorram Abad Agriculture Station. The experimental factors were: (M) Methanol foliar application (M1: distilled water (Control), M2: 10% (v/v) methanol, M3: 15% (v/v) methanol, M4: 20% (v/v) methanol, M5: 25% (v/v) methanol and M6: 30% (v/v) methanol); (V) wheat varieties (V1: Zagros, V2: Qaboos). Results showed that the effect of different levels of methanol foliar application on SPAD index and relative water content was significant and highest amount of these traits obtained in 20% methanol and 25% methanol resulted to highest biological and grain yield but methanol application had no significant impact on protein content. Highest leaf area, biological yield and grain yield obtained in Qaboos variety and highest protein content observed in Zagros variety. It appears that foliar application of methanol resulted to decrease in photo-respiration and increasing accessibility of carbon resulted from methanol degradation and Qaboos variety produced more grain yield and vegetative growth due to higher adaptability with growth medium conditions.

Change any of the environmental factors can basically have effect on processes on plant growth and ultimately on production and operation on crops. Scarcity of water is a severe environmental constraint to plant productivity. Drought-induced loss in crop yield probably exceeds losses from all other causes, since both the severity and duration of the stress are critical. Seed priming is a presowing treatment that exposes seeds to a certain solution that allows partial hydration but not germination, and redried to original moisture content. Although the germination is not completed, metabolic activities that prepare seeds for radicle protrusion may be initiated during priming. Many evidences have shown seed priming could improve germination and early seedling growth under stress conditions compared to plants grown from untreated seed. Allelochemicals can stimulate the growth at very low concentrations but could inhibit the same at higher concentrations. The stimulatory activity of any compound at lower concentrations is called hormesis. The availability of some chemicals at lower doses could affect the plant hormones and are responsible for growth stimulation, while they might have growth retarding activity at higher doses due to the same or another mechanism of actions. In most of researches negative allelopathic effects surveyed, but little researches had done on posetive allelopathic effects.
This investigation had doen in order to survey effect of safflower seeds priming with fennel, cumin and mint water extract (without priming, hydropriming, priming with 1 and 2% concentration) in different irrigation regimes. Investigation had done in laborator as factorial based of completly accidental design and in field as split plot based on complete block design.
Based on results of this investigation in greenhouse condition safflower seed priming by medicinal plant extract improved germination and seedling growth and physiologic properties improvement. It seems improvement in safflower seedling growth caused by improvements in safflower seedling physiologic properties. It seems improvements in safflower seedling growth and germination in drought and full irrigation is due to an increase in proteins, gibberellin and carbohydrate content. In field drought decreased safflower seed yield. There were not significant differences between irrigation after 70 mm evaporation from evaporate basin and irrigation after 100 mm evaporation from evaporate basin, but harsher drought decreased safflower yield. Decreasing water from irrigation after 70 mm evaporation from evaporate basin to irrigation after 130 mm evaporation from evaporate basin, decreased grain yield by 38.2 %. But priming with medicinal plant extract caused significant increase in this trait. In this investigation safflower seed priming by all three concentrations of extracts decreased safflower grain yield. But highest increase observed in 1 and 2 percent concentration. This two concentration of medicinal plant extract increased safflower grain yield by 50.9 and 47.6 %. In both mint and cumin higher grain yield observed than fennel, but there were not significant difference between mint and cumin water extract in safflower grain yield.
Based on results of this investigation safflower seed priming with medicinal plants water extracts not only increases safflower grain yield in full irrigation, it also increases safflower grain yielg in drought condition.

This study aimed to investigate the relationship between morphophysiological and phenology traits with grain yield to determine the best indices of direct and indirect selection in the field of genetic improvement of aerobic rice grain yield in Khuzestan province with 12 aerobic rice genotypes. The traits such as include the grain yield as the dependent variable and total dry matter, panicle weight, stem weight, LAI, CGR, NAR, LAR, SLA, ALW, LWR, L/S, SWR, PWR, LAD and BMD as independent variables, which were analyzed by stepwise regression at different growth stages to determine their effect on grain yield. The results showed that on 25 days after planting traits of L/S, SLA, LAI and leaf weight, on 50 days after planting traits of NAR, L/S, SWR, stem weight and BMD, on 75 days after planting traits of NAR, SLA, stem and LAR, on 100 days after planting traits of CGR, stem, L/S, LAR and PWR and on 125 days after planting traits of CGR, NAR, SLA, L/S and leaf affected the grain yield. In order from the beginning to the end of the growth, traits of L/S, NAR, panicle weight, CGR and CGR had caused the greatest changes in the grain yield. According to the critical period of growth, CGR was the most effective trait on the grain yield because of allocation of more assimilates in the reproductive growth instead of vegetative growth during grain filling period, thus it can be an important objective in the breeding researches.

Salinity is a multidimensional stress affecting crop yield and productivity at various levels of plant organization. The plant response to salinity consists of numerous processes that must function in coordination to alleviate both cellular hyper osmolarity and ion disequilibrium. In addition, crop plants must be capable of satisfactory biomass production in a saline environment (yield stability). Excess of salt concentrations causes enhanced generation of reactive oxygen species (ROS) in plants. In contrast, plants are equipped with a diverse array of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX) and polyphenol oxidase (PPO) against oxidative damages by reactive oxygen species. Turnip (Brassica rapa L. subsp. Rapifera) as a source of strong health food, contain a variety of antioxidants and Iran is one of the main centers of diversity. Indigenous accessions has a set of morphological, physiological and phenologycal that increase water use efficiency in the soil in saline and dry environments. Study of physiological and biochemical changes made in understanding the mechanisms of resistance to salinity stress conditions and access to genetic resources for breeding programs is essential. According to the limited information available in the field of physiological and biochemical reactions turnip cultivars to salinity, especially in indigenous accessions, in order to determine the response of morphological, biochemical and enzymatic turnip indigenous masses to salinity, the research carried out was.
This study aimed to assess the response of Iranian indigenous turnip accessions to salinity stress in terms of biochemical traits and antioxidant enzymes activity, to further understanding of salinity resistance mechanisms in plants and access to better genetic resources. The indigenous turnip accessions including Ardakan, Shiraz and Kermanshah evaluated at four levels of soil salinity (0, 60, 120 and 180 mM) as factorial experiment in a completely randomized design with three replications at Yazd Agricultural and Natural Resources Research Center, during 2013. Twenty days after the first germination as salinity treatments were done gradually. Eight weeks after salt treatment, the sampling for biochemical traits (proline, total phenols, malondialdehyde, catalase and superoxide dismutase) from the youngest mature leaves were separated from each other and then shoot and root traits morphology (root and shoot dry weight) were measured. SAS data analysis was used to compare the means and the Duncan´s (P ≤ 0.5) test.
The results showed that morphological traits such as shoot and root biomass, were mainly affected by severe salinity stress, but salinity stress (120 and 180 mM) had no significant effect on these traits. In this study, increased salinity stress increases the leaf proline and malondialdehyde content and reduced total phenolic in all accessions. The highest proline obtained in sensitive indigenous accessions (kermanshah) at severe salinity stress. Enzymes activity of superoxide dismutase and catalase increased in salinity resistant accession kermanshah than other accessions. Existence or poor performance of salinity tolerance or avoidance mechanisms in kermanshah accession possibly caused induction of oxidative stress and produced antioxidant enzymes. In terms of salinity, plant to reduce the effects of oxidative stress antioxidant enzymes such as superoxide dismutase and catalase activity increases. The activity of the enzyme superoxide dismutase and catalase negative correlation with leaf malondialdehyde (-0.88**,-0.91**) there. Also, a significant positive correlation (0.9**) between activity of catalase and superoxide dismutase indicates a close relationship between these two enzymes in removing free radicals.
Shoot and root biomass were mainly affected by high salt stress and accession Ardakan shoot biomass was highest, maybe the accessions to fight the salinity of sodium and chloride ions into the cell vacuole leaves the store. In this study, increase of salinity, proline and malondialdehyde increased in all accessions. Accession kermanshah were the most proline in extreme conditions of salinity, which indicates the ability of the accessions to accumulate proline, malondialdehyde and other organic solute to prevent oxidative stress and maintain inflammation plant cells. The effect of salinity stress, superoxide dismutase and catalase enzyme activity were sustained in the accession production of these enzymes, a sign of oxidative stress caused by salinity.

To study the effect of salt stress on morphological and physiological traits of different Brassica species a greenhouse experiment was conducted in Tarbiat Modares University. Eighteen rapeseed cultivars (fifteen cultivars of B. napus and three cultivars of B. rapa)، and two levels of soil salinity (2 and 12 dS. m-1) were experimented as factorial arrangement in randomized complete block design with three replications. The total experiment duration was 50 days (time from planting to the end of rosette stage). Results showed that salt stress reduced number of leaf، leaf area، weight of petiole، blade and biomass. However salt increased the water content and relative water content of leaf، but the ratios of blade to petiole weight and phloem to xylem weight. The lowest variation was observed in the relative water content of leaf، whereas the highest variation was in biomass and leaf water content. There was no significant correlation between biomass and number of leaf. Biomass was significantly correlated with the blade area and weight. Salinity decreased the total and chlorophylla and chlorophyllb contents، potassium (K+)، ratio of potassium to sodium (K: Na+) in blade and membrane integrity. Salinity increased the concentration of Na+ in blade. Increase in the concentration of Na+ was higher than decrease in the concentration of K+ in blade. Salt stress had no effect on a/b chlorophyll and other plant pigments such as carotenoid، antocyanine and flavonoids. The concentration of proline increased in B. napus and decreased in B. rapa with increasing salinity. No significant correlation was found between proline and biomass in both species. Results of this study demonstrated that B. napus coped better with salt stress than B. rapa in early stages of growth which can be attributed to the amphidiploidy of B. napus.