JOURNAL OF PLANT PROCESS AND FUNCTION
Year:2016 | Volume:5 | Issue:15|Papers Count:16

In order to investigate the effect of different levels of water stress on Satureja hortensis, a completely randomized design (CRD) with four replications was carried out in the greenhouse ofYazd University in 2014. The water stress treatments including 100, 75, 50 and 25 percent of field capacity (FC) were applied. The results showed that water deficit stress significantly (p<0.01) decreased plant height, canopy cover volume, canopy cover surface, shoot and root" dry weight, root thickness as well as soluble sugars content. Also, proline, chlorophyll content and root length significantly increased under drought stress. The maximum amount of proline, a, b and total chlorophyll and root length were observed in 25% of field capacity. Maximum plant height, crown volume and leaf area were obtained at 75% of field capacity. The shoot and root dry weight and crown area were observed in plant treated at 100% of field capacity. The overall results of this study showed that S. hortensis could be adapted to drought stress by using some avoidance mechanisms such as reduced plant height, plant volume, surface and crown diameter, shoot and root dry weight, root thickness and increasing of chlorophyll contents and proline.

Peach has high nutritional values that can be used either fresh or processed. Thus, in this study, the effect of different levels of methyl jasmonate (0, 100 and 200mgL-1) and salicylic acid (0, 1 and 2mM), and their interactions on increasing qualitative and antioxidant characteristics at harvest time of “Elberta” peach were investigated. In doing so, trees sprayed in two stages of green tip and pink tip of bud, in a split-factorial experiment in a randomized complete block design with 4 replications under field conditions. At harvest time, many of the qualitative and antioxidant characteristics of fruits’such as total soluble solid, organic acids, vitamin C, carotenoids, anthocyanin, phenol content were studied. Generally, the results showed that spraying at both stage increased qualitative and antioxidant characteristics of fruits compared with control fruits and between treatments, methyl jasmonate 200mgL-1 and combined with salicylic acid ImM had highest effect on improving quantitative characteristics of fruits and spraying at green tip was effective compared with pink tip stage.

Air pollution is a serious problem in recent years and is progressively on the increases. This study was accomplished in order to enhanced understanding of morphological and physiological responses of acid rain on Persian maple trees as an ornamental and industrial plant. Accordingly, three-year old Persian maple seedlings were subjected based on completely randomized design to four different acid rain regimes: pH 3, 4, 5 and near neutral (pH 6) as control, in tree replications, during 10 days. At the end of experiment, some visible changes such as necrotic spots and leaf marginal wrinkle were observed in the plant leaves sprayed only with AR of pH 3. Results showed that electrolyte leakage (EL) and lipid peroxidation (LPO) amount increased significantly as pH values of AR decreased. However, reducing of AR had no effect on leaf chlorophyll content by pH 4.0, whereas AR of pH 3.0 dramatically degraded it. In addition, AR did not significantly affect superoxide dismutase (SOD) activity. On the contrary, it enhanced peroxidase (POD) and ascorbate peroxidase (APX) activities by pH 4.0, but AR of pH 3.0 markedly decreased them, thereby, the ant ioxidative system was weakened and injury appeared. Overall, our results cleared that Persian maple was resistant to AR by pH 4.0, while it was indicated susceptible to pH 3.0 and lower pH values.

The elements of Zn and Mn are essential for ‘growth of microalgae but their build up promote biological problems for microalgae structure in aquatic environments. In this research, exclusive effects of different concentrations of Zn (450, 900 and 1350 mg/l) and Mn (75,150 and 225 mg/I), and their combined effects (450+75, 900+150, and 1350+225 from Zn+Mrr’ in mg/l)" on "some physiological parameters of population dynamic, growth, chlorophyll and carotenoid contains in green microalgae Scenedesmus quadricauda were investigated under laboratory conditions of temperature of 22±2 °C, photoperiod of 12 hours light: 12 hours dark, and light intensity of 80 umol photons/m2/s. The experiment was carried out as completely randomized design with three replications for a 22 days period. Results showed that the peak of population density obtained at 900 mg/L of Zn, 150 mg/l of Mn and their combination 900+150 mg/I of Zn+Mn. The maximum growth rates were 0.060, 0.058 and 0.056 /day for Zn, Mn and their combination, respectively. The minimum doubling time of population attained 11.6 days at 900~mg/1 of Zn. The maximum chlorophyll a and total carotenoid were 1.8 and 93.2 mg/L, respectively, at 900 mg/L of Zn which had significant differences with other treatments. The findings of this study showed that increasing of Zn up to 900 mg/L and Mn up to 150 mg/I that resulted to improving of population, growth, chlorophyll a and total carotenoid in the S. quadricauda. As conclusion, this study illustrated that changing of Zn and Mn concentrations had significant effects on cell density, chlorophyll a and total carotenoid. The effects of Zn were higher than Mn and its increasing to concentration of 900 mg/I caused improving of physiological characters of S. quadricauda.

Industrial activities lead to the entry of heavy metals into the environment and food chains. Regarding growth around steel production industries of Ahvaz and edible and medicinal importance of Malva parviflora in Khouzestan Province, Zn uptake and accumulation were studied in this plant. After collecting from the area, the seeds were sown on the soil. Subsequently, four-week plants were transferred to hydroponics system including 0, 250, 500, 1000, 1500, 2000 mm Zn (NO3)2. The plants were harvested 0, 3, 6, and 9 gays after addition of Zn different concentrations. The results showed that along with increasing Zn concentration of solution culture, Zn content increased in the shoots during experiment performance, meanwhile dry weight and Zn accumulation in the roots decreased but increased in comparison with aboveground parts, respectively. There was a notable reduction of the root Zn extent in the concentrations higher than 1000 mM. Concerning TF < I and root BF > 1, it is assumed that M parviflora comprises low potential to trans locate Zn from the roots to the shoots. However, there is high capacity for this plant to accumulate Zn in the roots and exclude from the shoots under these conditions.

To find out the effect of planting date and plant density on antioxidant capacity, phenolic compounds, yield dry matter and characteristics of medicinal plant purple coneflower root, a randomized complete block design in split plot arrangement with three replications was conducted in Research Farm of Sari Agricultural Sciences and Natural Resources University in 2012-2013. Experimental treatments included three planting dates (April 9, May 9 and June 8 2013) and three plant density (7, 10 and 16 plant/m/2). Measurements were performed in full bloom stage. Results of experiment showed a significant increment of penetration depth of root in 9 May with a density of 16 plant/m2. The highest root volume and dry matter were related to 8 June and 7 plant/m2. However, the highest total dry matter (130.5 g/plant) was related to the purple conflowers that planted on 9 April with 10 plantlm2. Plants grown on 8 June with a density of 7 plant/m2 resulted to the highest ratio of dry matter root to total and root to shoot. The highest cichoric acid (19.5 mgl g dry matter) and total phenol (30.8 mg of GAEl g dry matter) content of root were observed in plants grown in 9 May with a density of 16 plant/m2. The highest amount of total flavoneid and antioxidant capacity of root were measured in coneflower plants that planted in 8 June with a density of 16 plant/m2. In conclusion, it seems that late planting date 8 June in this experiment conditions is suitable for more root dry matter, total flavoneid and antioxidant capacity, while planting dated 9 May was suitable for more cichoric acid and phenollic content in the root of the coneflower plants. In addition, low density of 7 plant/m2 resulted in increase in root dry matter but decrease in cichoric acid and total phenol content as well as antioxidant capacity in conflower roots.

Drought is one of the most significant abiotic stresses that affects plant’s growth and development. Wild barley, Hordeum vulgare ssp.spontaneum, the progenitor of cultivated barley has a high potential in terms of tolerance to environmental stresses. This research was performed on nine spontaneum genotypes, in a split plot experiment based on Randomized Complete Block Design with three replications under field shelter in 2011-2012. The main plot included three levels of water stress as normal irrigation, water withholding at flowering stage and no irrigation and sub-plots comprised the studied genotypes. The results indicated that the effect of drought stress on plant height, grain yield, biomass, relative water content, osmotic adjustment, stomatal conductivity, chlorophyll content, catalase, ascorbate peroxidase and peroxidase, protein, malondialdehyde, and proline was significant (P<0.01).The results of principal component analysis on the whole evaluated traits in drought stress condition located the studied genotypes in four groups. The first and second group comprised genotypes 6, 4 and 5. These genotypes had significantly higher grain yield, relative water content, chlorophyll content, enzymatic activity of peroxidase and ascorbate peroxidase and lower content of malondialdehyde, leaf temperature and osmotic potential (more negative) and therefore, were regarded as tolerant genotypes.

Salt stress decreases plants crop growth including rice. This research was carried out to evaluate responses of rice genotypes to salt stress using a factorial experiment with randomized complete block design in three replications, at Dankook University, South Korea in 2012: First factor was 16 rice cultivars at vegetable growth stage and second factor was soil salinity levels (0.8 ds m-1 as control and 6.2 ds m-2 ). Salt stress disturbed cell membrane stability. The highest shoot dry weight was decreased in IR67075-2B-5-2 (153.8 g m-2), Kochihibic (152.2 g m-2), Haraz (149.8 g m-2), Shafagh (152.0 g m-2) and Nemat (156.9 g m-2) cultivars. These cultivars showed maximum K+/Na + rate, antioxidant enzymes activates, relative water cotent, soluble carbohydrate and photosynthesis rate and minimum leaf Na+ concentration. Results indicated IR67075-2B-5-2, Kochihibic, Haraz, Shafagh and Nematwere salt tolerante cultivars compared with other rice cultivars.

Thioredoxins are involved in redox regulation of many cellular "processes. In this study the role of NADP+- Thioredoxin reductase C (NTRC) in the: control of leaf senescence was investigated by biochemical characterization of Arabidopsis ntrc mutants, Forty days. oldwild type and two ntrc mutant lines were incubated either under normal dark-light or contino us darkness regimes for 6 days as control and senescence treatment, respectively. Growth parameters, the contents of carbohydrates, pigments and the activity of some antioxidant enzymes were compared between wild type and ntrc mutant lines during dark induced senescence. Darkness led to decreased fresh and dry weights, chlorophylls and carotenoides, starch and protein contents in both wild type and mutant plants and there were no significant differences in the interactions of genotypes and treatments regarding to theses parameters. Darkness also induced the accumulation of anthocyan ins, total and non-reducing sugars however, the accumulation of the carbohydrates in mutant lines was more pronounciated than wild type plants and again there were no significant differences in response of wild type and mutants to dark treatment. The activities of catalase, peroxidase and polyphenol oxidase of mutant lines were significantly greater than wild ype plants. While darkness decreased the activities of ascorbate peroxidase and catalase it led to increased activities of peroxidase and polyphenol oxidase especially in the mutant lines. There were significant differences in the activities of all four enzymes between mutant and wild type plants in response to darkness. Thus, it appears that defects in NTRC mainly affects the activities of antioxidant enzymes rather than the other studied biochemical parameters of plants during the senescence process. This study might be useful in future breeding programs for controlling senescence process to achieve better performance of crop plants.

Study of physiological responses of recombinant inbred lines (RlLs) to drought stress could help to understand the drought tolerance mechanisms. For this reason a field experiment was conducted to evaluate the effect of drought stress on chlorophyll content, leaf proline content, leaf length, leaf width, leaf area, peduncle length and plant height using 169 RILs, in two separate simple lattice design with four replications using two moisture regime of normal and water deficit stress, Irrigation regimes were performed based on Class A-pan of 70 and 130 mm evaporation from Class -A -pan and moisture content of soil in effected root depth. The RILs were obtained by crossing between a tolerant and sensitive wheat cultivar. The result of analysis of variance showed a significant difference among Rll.s. Drought stress caused a decrease in the chlorophyll content, leaf width, leaf length, peduncle length, leaf area but an increase in the proline content. Although drought stress increased the proline content and decreased the peduncle length and leaf area in both tolerant and sensitive line groups, these declines in tolerant lines were lower than sensitive lines. Therefore, it may be possible to use the physiological traits comprising proline amino acid content, peduncle length and leaf area as a selection tool for selecting drought tolerant lines in bread wheat.

To study the effect of Piriformospora indica and paciobutrazol (PBZ) as a plant growth regulator for inducing cold stress tolerance in green beans plant (Phaseolus vulgaris L.), a greenhouse experiment was performed as a factorial arrangement based on completely randomized design with three replications at Sari Agricultural Sciences and Natural Resources University during 2013. Treatments consisted of three cold stress levels (control, three and six days cold stress at 5°C), two levels of fungi inoculation (non-inoculated and inoculated with P. indica) and three levels ofPBZ (0, 40 and 80 ppm). P. indica was inoculated prior to planting and PBZ was sprayed five and six weeks after planting. Eight weeks after planting, green bean plants exposure to cold stress and some morphological and physiological growth characteristics and activity of antioxidant enzymes consisting of catalase (CAT) and guaicol peroxidase (GPX) were measured. The results showed that the six days of cold stress particularly reduced aboveground shoot morphological traits such as height (approximately 2%) and GPX enzyme activity, but CAT activity increased (about 1.3 times). Also P. indica inoculation was increased the nod number about 8% in six days and RWC (approximately 3 and 11%) and CAT activity (up to 2.16 times and 34%) in three and six days cold stress, compared to non-inoculated plants. In all cold stress levels, 80 ppm of PBZ increased the CAT activity (50, 159 and 87). The results of this study confirmed the positive role of P. indica and PBZ on growth and improving plant resistance to cold stress in green beans.

One of the most important limiting factors of crop growth in the arid and semi-arid regions is water deficit stress. Mycorrhizal fungi are one of the most important microorganisms in the rhizosphere. The effects of these fungi apply via changes on some of the characteristics of roots and nutrient uptake in host plants under drought conditions. In order to evaluate the effect of arbuscular mycorrhizal fungi under drought stress on linseed, a field experiment was conducted as split-plot design in RCBD with three replications at the research station of faculty of Agriculture in Shahrekord University in 2013. Drought stress at four levels of no stress, mild, medium and severe stresses as main factor and inoculation with Glomus intraradices, Glomus mosseae and no inoculation as sub factor were treated. The results showed that the effect of mycorrhiza inoculation and drought stress treatment were significant on all the measured traits. The interaction between mycorrhiza and drought stress treatments were significant in all measured traits except, root length, root/shoot ratio and uptake of phosphorus. Drought stress decreased all measured traits, but increased root/shoot ratio. The results showed that the maximum (32.82%) and the minimum (8.68%) root colonization rate were obtained in no drought stress + inoculated with G. intraradices and under hard stress + no inoculation of mycorrhiza respectively. Based on the results of in this experiment, symbiosis oflinseed with of arbuscular mycorrhizal fungi caused an increase in all traits.

The use of micronutrient fertilizers, such as zinc under the condition of natural limiting factors such as salinity can be a great help in the development of medicinal plants cultivated in many parts of this country. In order to study the response of Plantago ovata to zinc application under salt stress, a pot experiment was conducted in 2013, as factorial experiment based on a complete randomized design with four replications. Treatments were five levels of salinity (0, 50, 100, 150 and 200 mM NaCl) and three levels of zinc (3.85, 7.7 and 11.55 mM ZnSO4). The interaction effects of salinity and zinc on physiological parameters of Plantago ovata were significant. With increasing concentration of zinc at zero, 100 and 150 mM salinity, leaf soluble sugar increased 50%. At zero and 200 mM salinity, !yith increase zinc concentrations, levels of proline were increased over two times. Salinity increased the percentage of electrolyte leakage, so that by increasing the salinity level, leakage rate was increased from 30 to 50%. Leaf soluble protein with increasing amounts of zinc, increased 36%. Generally, use of 7.7 mM zinc in all of traits associated with a better outcome, and also, if a large amounts of zinc in a high salt concentrations was used, the amount of compatible solutes (leaf soluble sugars and proline) increased. Therefore, to reduce the effect of salinity zinc concentration can be used in Hoagland solution up to 7.7 mM.

The varying seed pnrnmg methods have beer widely used for improving germ inability and seedling establishment of numerous economic plants especially under environmental stresses. In this context, in order to evaluate the advantage of priming on different physiological and biochemical indices of black cumin seed germination and seedling growth in saline conditions, a factorial experiment was conducted based on RCB design with four replicates in the Faculty of Agricultural Science Laboratory Complex. Experimental factors included five priming methods (non-priming control, priming with calcium nitrate, nano zinc oxide, calcium nitrate+nano zinc oxide and hydro-priming) and three salinity levels (0, 50 and 100 mM NaCl). The results of the present research indicated that despite the inhibitory effect of salinity on black cumin seed germination and seedling growth characteristics, seed pre-treatment substantially alleviated the deleterious impacts of salt due to enhancement of prescribed parameters, When NaCI concentration increased in germination medium, total protein content of seedling was reduced and catalase activity was upregulated, while seed priming caused an increase in both traits under salinity. Among the applied priming methods, seed pre-treatment with calcium nitrate+nano zinc oxide had the highest efficacy and the best performance in ameliorating inhibition of measured parameters of black cumin induced by salt.

Nitrogen and phosphorus are the most important components of plant nutrition. However inappropriate use of these nutrients can affect physiological aspects of plant. Therefore, in order to evaluate the response of some physiological parameters in purslane sucuulent .plant to nutrition, an experiment was conducted as a RCBD with a split plot in time arrangement, which that nine levels of plant nutrition (To: control (no fertilizer); T1: N-based broiler litter; T2: P-based broiler litter; T3: N-based cattle manure; T4: P-based cattle manure + urea; Ts: chemical fertilizer equivalent T1; T6: chemical fertilizer equivalent T2; T7: chemical fertilizer equivalent T3; and Tg: chemical fertilizer equivalent T4 as a main factor and two levels of harvest date (27 July and 16 August) as sub factor. The results indicated that fertilizer treatments significantly increased chlorophyll a and chlorophyll b content compared to the control (no fertilizer). In the first harvest, the T, treatment (0.33 mg gol) showed the lowest carotenoids content, In the second harvest, the lowest carotenoids content was obtained in T2 and T7 treatments (0.43 and 0.45 mg gol, respectively) which that there were no significant difference among TI and T3 treatments. Dry matter partitioning of leaf: stem in broiler litter treatments (60.3:39.7) was more balanced than cattle manure treatments (63.6:36.4). Nitrate amount of BL and CM treatments was significantly lower than the chemical fertilizer treatments. In general, it can be concluded that purslane photosynthesis and production were more affected by broiler litter application than the chemical fertilizer and cattle manure, which ultimatly causes a considerable increase in crop production and health.

To evaluate the effect of airborne dusts on some physiological characteristics and yield of different wheat cultivars, a field experiment was conducted at Research Farm of Razi University, Kermanshah, Iran in 2013. The evaluated treatments included: 1) shoot washing-fin two levels: washing and unwashing) and 2) three wheat cultivars (Pishgam, Zarin and Behrang). In this research, characteristics such as grain yield and its components and relative water content, green area, greenness index, soluble protein, stomatal conductance and temperature of flag leaf were evaluated. Results of variance analysis showed that, airborne dusts caused significant reduction in grain yield (380 kg ha-1) and biomass (560 kg ha-1) of wheat cultivars. Pishgam and Zarin with 6.83 and 4.83 ton ha-I had the highest and the lowest grain yield. Under un-washing treatment of dust from the leaf grain yield significantly reduced. Under this treatment, Pishgam and Zarin cultivars had the lowest (3%) and the highest (12%) reduction in grain yield respectively. Also, airborne dust significantly reduced grain number per spike and leaf area, soluble protein, greenness’ index, stomatal conductance and temperature in flag leaf of evaluated cultivars. The evidence from this study suggested that, with respect to the high probability of airborne dusts occurrence in Kermanshah in the next years and its negative effects on grain yield and probably on grain quality, perhaps cultivation of Pishgam cultivar in this area is associated with lower risk.