JOURNAL OF PLANT ENVIRONMENTAL PHYSIOLOGY
Year:2019 | Volume:14 | Issue:1 (53) |Papers Count:7

Echinaceae prupurea, belongs to the Asteraceae family and is a perennial herb with different medicinal properties. The aim of the present study was to investigate the effect of salt stress on growth and some important biochemical parameters of this plant. For this purpose, Echinaceae prupurea plantlets were grown in Hoagland medium supplemented with different concentrations of NaCl (including 10, 50, 100, 300, and 500 mM) for 20 days. The experiment was carried out in a completely randomized design with five replications. The obtained result showed that the effects of different concentrations of NaCl were not significant on shoot dry weights. But root fresh and dry weights exhibited a significant increasing trend by 25 mM NaCl treatment. Meanwhile, the current data showed that increasing salt concentration in the medium caused an increase and decrease in soluble sugar level in shoots and roots, respectively. While salt stress did not show any significant effect on catalase enzyme activity, peroxidase enzyme activity was significantly increased by 75 mM NaCl treatment, in both shoots and roots. On the other hands, salinity treatment significantly decreased and increased total phenol levels in shoots and roots, respectively. The data from HPLC analysis demonstrated that the highest level of cichoric acid (1. 3 mg/g dry weight) was observed in roots of control samples. While NaCl at the level of 25 and 50 mM concentrations did not show any significant effect on cichoric acid amount, it was significantly decreased by 75 mMN aCl treatment. Moreover, 50 mM NaCl treatment enhanced 2 and 5 fold caffeic acid (precursor of cichoric acid) and chlorogenic acid level in root organ, respectively. It seems salt stress can increase the important medicinal secondary metabolites of Echinaceae purpurea.

The purpose of this study was to evaluate metabolites content (primary and secondary) and antioxidant activity of different organs of Ipomoea tricolor weed including stem, leaf, and fruit leaf, individually and in combination. The weed under study was first collected at fruit stage and divided into organs. Antioxidant activities of various organs of Ipomoea tricolor were measured according to the method of DPPH. Results showed that mixed organs of Ipomoea tricolor and then leaf had maximum total phenol contents in that order. In case of anthocyanins, the highest levels were obtained from leaf while the lowest content of both secondary metabolites were found in the stem. Results also showed that leaves had maximum soluble sugars and proline contents. Correlation coefficient of data showed a significant positive relationship between anthocyanin contents of various organs of Ipomoea tricolor and their soluble sugar and proline contents. According to the findings, content of protein and starch in various organs significantly decreased with an increase in the secondary metabolite contents of anthocyanins. Mean comparison of antioxidant activity of various organs of Ipomoea tricolor showed that leaf and fruit had the highest and lowest antioxidant activities for inhibiting free radicals, respectively. Regarding the effect of the type of Ipomoea tricolor weed organ on the quantity of metabolites especially secondary compounds like phenols and anthocyanins and also antioxidant activity, the plant, especially the leaves may be introduced as a notable candidate for oxidative decomposition of free radicals, improving the nutritional value of food, or as a natural herbicide due to its high biomass.

Global warming, due to the excessive use of fossil fuels, rising prices, environmental pollution, and greenhouse gas emission, have made scientists produce a renewable fuel as a replacement for fossil fuels. The aim of this study was to evaluate the potential of four species of green algae as raw materials for biodiesel production. After purification, samples were kept in BBM and N8 culture medium at 25° C, pH 7, and under constant light. Growth rate, chlorophyll content, carotenoid concentration, and lipid content were measured. The total fatty acid contents and fatty acid profiles were measured with FTIR and GC-Mass, respectively. Findings showed that the highest growth rate and biomass production, and the minimum division time and also the maximum lipid contents belonged to the green algae Scenedesmussp ISC 94. Moreover, palmitic acid (42. 74%), stearic acid (29. 56%), palmitoleic acid (10. 2%), oleic acid (6. 72%), linoleic acid (1. 72%), and α-linolenic acid (1. 64%) were measured in Scenedesmussp ISC 94. The fatty acid composition of the microalgal lipid comprised over %80 of saturated and monounsaturated fatty acids with a double bound. Also, palmitic and oleic acids were the majore fatty acids isolated. Therefore, ecause of high lipid production and the best lipid content, Scenedesmussp ISC 94 is recommended for its potential as a biodiesel feedstock.

In order to investigate the effect of mycorrhizal fungi and foliar application of putrescine on some biochemical characteristics, essential oil content, and biomass of basil (Ocimumciliatum L. ), a split plot in time experiment with three replications was performed based on a completely randomized design. Treatments included three levels of mycorrhizal fungi (control, Glomusmossea, and Glomusintraradicese) and three levels of putrescine (0, 1, and 2 mM) as main factors and two harvesting times as sub-factor. Results indicated that application of mycorrhizal fungi and putrescine influenced the biochemical traits, fresh and dry biomass of aerial parts, and essential oil content of the plants. The highest amount of chlorophyll a and essential oil content were observed at G. mossea and 2 mM putrescine application in the first harvesting time. The highest amounts of chlorophyll b and carotenoid were obtained at G. intraradicese and 2 mM putrescine application in the first harvesting time. But with increasing the day time length and temperature, the amount of photosynthetic pigments in the second harvesting time decreased. The highest antioxidant activity and total phenolic content were observed in the treatment of G. intraradicese without putrescine spraying in the second harvesting time. The highest fresh and dry biomass of aerial parts were observed by applying G. mossea; but, no significant difference was observed between the two concentrations of putrescine and only a significant increase was recorded in comparison with no putrescine treatment. Generally, applying both types of mycorrhizal fungi as biofertilizers with foliar application of 2mM putrescine could significantly improve the traits in this study.

In order to investigate the effect of seed priming on the purification capacity of heavy metals chromium and lead and growth traits of purslane, an experiment was conducted at two stages of the field and the laboratory during 2017. The experimental design was conducted in a completely randomized design with 3 factors in a factorial layout with 3 replications in a pot. Treatments in the field included seed priming (by 1mM salicylic acid), non-primed seeds, and different levels of chromium (0, 25, 75, and 100 mg/kg) and lead (0, 50, 150 and 300 mg / kg). Results showed that different levels of chromium and lead had significant effects on morpho-physiological characteristics of the plants. With increasing heavy metal concentration, fresh/dry weight of root/shoot and shoot extraction significantly decreased compared to control. The highest values of fresh/dry weight of root/shoot and shoot extraction were obtained from primed seed and no heavy metals treatment while the lowest levels were obtained from the highest levels of chromium (100 mg / kg) and lead (300 mg / kg) treatments in non-primed seeds. Based on the obtained results, seed priming with salicylic acid had increasing effect on the remediation of chrome and lead elements from soil.

In order to investigate the response of yield and yield components of spring rapeseed varieties in cultivation of winter to plant density under selenium treatment, a factorial experiment was carried out in split-plot randomized complete block design with three replications in the Research Institute of Plant Improvement and Seeds of Karaj in crop years 2014 and 2015. Plant density at three levels (40, 60, and 80 m2) and selenium at two levels including control (non-sprayed with water) and foliar application of selenium (30 gL-1 sodium) were considered in the main plots and variety at five levels (Sarigol, Hyola 401, Jacomo, Jerome, and Dalgan) were considered as subplots. Results showed that the year, plant density, selenium, variety and plant density + year, and variety + plant density had significant effects on the on number of pods per plant, the number of seeds per pod, seed weight, and seed yield. Dalgan variety at 40 m2 density showed the highest seed weight and its seed yield was higher than other varieties. This variety showed the highest biological yield (16622. 225 kg ha-1) under 40 m2 density. Also, based on the analysis of the data the highest yield in both years was obtained in treatments including spraying selenium.

Drought is one of the most important environmental stresses that causes decreased production and yield in arid and semi-arid areas. The aim of this study was application of some amending compounds in soil to increase marigold plants’ (Calendula officinalisL. ) resistance to drought stress. Experiments were performed in factorial according a completely randomized design with three replications. Treatments consisted of six amendment compounds namely, control (only soil), 1 and 2 g/kg nano-potassium fertilizer, 30% of vase volume cocopeat, 30% of vase volume palm peat, and 30% of vase volume madder plant residues) and three levels of drought stress (40, 60, and 80% of field capacity). According to the results by increasing the drought level, fresh and dry weights of flower and root significantly decreased while peroxidase enzyme activity significantly increased. The maximum fresh and dry weights of flowers and roots were obtained in plants treated with madder residues. The lowest fresh and dry weights of flowers and roots at all drought levels were obtained in plants treated with palm peat. Plants were treated with palm peat did not show reproductive phase and flower at all three levels of drought. Fresh weight of flower had significant correlation with dry weight of flower, fresh and dry weight of root, and phosphorus uptake. Generally, results showed that madder residues in comparison with other treatments increased marigold resistance to drought stress and could be introduce as a suitable organic compound for culture media.