جستجوی مقالات مرتبط با کلیدواژه "total flavonoid" در نشریات گروه "زراعت"

AbstractNitrate accumulation is a common problem in most leafy vegetables and it happens when the amount of nitrate absorption exceeds the amount consumed by the plant. This study was conducted as a factorial experiment in the form of a completely randomized design and in three replications. The first factor included adding nitrate (calcium nitrate) to Hoagland's standard solution at three levels of 0, 10 and 20%, and the second factor was adding different concentrations of molybdenum from sodium molybdate salt at four levels of 0, 0.5, 1.5 and 3 µM. The measured traits included traits of some growth characteristics, total phenol and flavonoids, ascorbic acid, spinach leaf nitrate. According to the obtained results, fresh and dry weight of leaf, dry weight of root and percentage of dry matter increased by increasing calcium nitrate concentration up to 20% and molybdenum application up to 3 µM in nutrient solution. The simultaneous application of molybdenum and nitrogen had no significant effect on total phenolic, total flavonoid and ascorbic acid traits, and the highest amount of these traits was observed in 3 µM molybdenum. The highest amount of leaf nitrate (3247.4 mg kg-1 FW) was observed in the treatment of 20% additional nitrate along with molybdenum. Based on the results, the use of molybdenum in nutrient solution had a reducing effect on nitrate accumulation in spinach leaf, therefore adding 3 µM sodium molybdate to Hoagland nutrient solution in hydroponic system for spinach production is recommended to obtain the maximum amount of antioxidant compounds and the minimum amount of nitrate accumulation.IntroductionPlants take nitrogen (N) either as nitrate (NO3−) or ammonium (NH4+) form for various growth and developmental processes; however, NO3− is more important for such processes. For most of the crop plants, the nitrate form is mobile, less toxic, and can be stored in vacuoles. However, Nitrate must be reduced to NH4+ before it can be utilized for the synthesis of amino acids, proteins, and other nitrogenous compounds in plant cells. Nitrate reductase (NR) and nitrite reductase (NiR), the key nitrate assimilatory enzymes, are located in cytosol and chloroplasts and catalyze nitrate reduction to NO2− followed by NO2− to NH4+, respectively, in the leaf tissues. However, NH4+ is directly assimilated to produce different amino acids by the mutual actions of glutamine synthetase (GS) and glutamate synthase (GOGAT) enzymes in a cyclic manner within the plant cells. Nitrate accumulation is a common problem in most leafy vegetables and it happens when the amount of nitrate absorption exceeds the amount consumed by the plant. Molybdenum (Mo) is an essential microelement for higher plants and also a metal component of the Mo-cofactor, (Moco) biosynthesis. Moco binds to Mo-requiring enzymes and optimizes their activities for normal functioning of plant growth and developmental processes. Molybdenum plays a significant role in N metabolism, which includes nitrate reduction, assimilation, and fixation, by regulating the NR and GS enzymes activities and expressions. During symbiotic N fixation, Mo acts as a cofactor for nitrogenase enzymes to catalyze the redox reaction to convert elemental N into ammonium ions.Materials and methodsThis study was conducted as a factorial experiment in the form of a completely randomized design and in three replications. The first factor included adding nitrate (calcium nitrate) to Hoagland's standard solution at three levels of 0, 10 and 20%, and the second factor was adding different concentrations of molybdenum from sodium molybdate salt at four levels of 0, 0.5, 1.5 and 3 µM. This research was conducted in the research greenhouse of Campus of Agriculture and Natural Resources Razi University. Senator spinach seeds were obtained from Fardin Kasht Alborz Institute. Spinach seeds were disinfected with 1% sodium hypochlorite for 5 minutes and then planted in seedling trays containing cocopeat and perlite with a volume ratio of 1:1. The measured traits included traits of some growth characteristics, total phenol and flavonoids, ascorbic acid, spinach leaf nitrate.Results and discussion According to the obtained results, fresh and dry weight of leaf, dry weight of root and percentage of dry matter increased by increasing calcium nitrate concentration up to 20% and molybdenum application up to 3 µM in nutrient solution. The simultaneous application of molybdenum and nitrogen had no significant effect on total phenolic, total flavonoid and ascorbic acid traits, and the highest amount of these traits was observed in 3 µM molybdenum. The highest amount of leaf nitrate (3247.4 mg kg-1 FW) was observed in the treatment of 20% additional nitrate along with molybdenum. The most important point in this research was the use of molybdenum to control nitrate accumulation, and the use of molybdenum in concentrations of 1.5 and 3 µM was able to reduce the amount of nitrate accumulation in the aerial parts to some extent, thus neutralizing the toxicity of excess nitrate. The use of sodium molybdate can be one of the recommended ways to reduce the accumulation of nitrates and at the same time enrich molybdenum in spinach and increase the nutritional value of this plant.ConclusionNitrate and ammonium are the major forms of N that plants use for different growth and developmental processes. The present study revealed that Mo fertilizer plays a key role in N metabolism through regulating the activities and expressions of N-assimilating enzymes. In general, the results of this research showed that the increase in molybdenum concentration in hydroponic culture affected the growth and biochemical characteristics of spinach. Based on the results, the use of molybdenum in nutrient solution had a reducing effect on nitrate accumulation in spinach leaf, therefore adding 3 µM sodium molybdate to Hoagland nutrient solution in hydroponic system for spinach production is recommended to obtain the maximum amount of antioxidant compounds and the minimum amount of nitrate accumulation.

Taking advantage of the symbiotic relationship between plants and Trichoderma fungi is one of the ways to reduce water stress in plants. The present study was conducted in order to investigate the effect of Trichoderma fungus on the antioxidant properties of the basil medicinal plant (Ocimum basilicum L.) under water stress conditions.

This experiment was carried out in the greenhouse of the Department of Horticulture Sciences of Ahar Faculty of Agriculture and Natural Resources and laboratory studies in the basic and general laboratories of Ahar Faculty of Agriculture and Natural Resources (University of Tabriz) in 2019 in a factorial manner based on a randomized complete block design with three repetitions. The treatments included different levels of water deficit stress, including severe stress (25% of field capacity), moderate stress (50% of field capacity), mild stress (75% of field capacity), and no stress (100% of field capacity). Each pot contained a commercial mushroom species Trichoderma harzianum Na-lac with concentrations of 109 and 106 spores per milliliter as the inoculum.

The results showed that the amount of malondialdehyde, catalase and peroxidase, antioxidant activity and total flavonoid increased with the application of dehydration stress. The concentration of 106 spores per milliliter had a better impact on improving the mentioned indicators. Based on this, Trichoderma fungus proves effective when improving the antioxidant status of plants under drought stress and can prevent the effects of oxidative stress in plants by reducing the oxygen free radicals produced.

The results indicated that the use of Trichoderma mushroom in comparison with the control (without inoculation with the mushroom) can be a suitable tool to improve the physiological traits and antioxidant activities in the conditions drought stress.

Lavender is widely cultivated worldwide with its economic and ornamental potential and its high use in the cosmetic and pharmaceutical industries. Drought is one of the most important factors limiting plant growth worldwide and the most common environmental stress. In general, drought is considered to be the major environmental factor causing disturbance in water status and having a key impact on physiological and biochemical processes such as increased plant osmolality. In response to environmental stresses, abscisic acid plays an important role in initiating and coordinating many physiological and biochemical processes in reducing oxidative stress. Due to the fact that drought and water deficit in Iran is always one of the most important agricultural problems and due to the unique medicinal properties of lavender, the present study was conducted to evaluate the yield, physiological and biochemical properties of Lavandula angustifolia cv. Organic Munstead in irrigation regimes and application of abscisic acid was performed in order to understand how to induce drought tolerance.

In order to study the effects of drought and abscisic acid on physiological and biochemical characteristics of Lavandula angustifolia cv. Organic Munstead, a pot experiment was conducted as factorial based on randomized complete block design with three replications at Plant Production faculty of Gorgan University of Agricultural Sciences and Natural Resources, during growing season of 2017-18. The first factor was irrigation regimes in four levels (30-40, 50-60, 70-80 and 90-100% field capacity) and the second factor was abscisic acid spry including three levels (0, 15 and 30 µM/L). Traits evaluated were wet and dry weight and leaf area index, total phenol, total flavonoid, DPPH antioxidant activity, proline, carotenoid, RWC and soluble carbohydrate.

The results showed that drought increase phenol (151.42 mg/g) and carotenoid (46.32 mg/g) compared to control. Abscisic acid had significant effect on all traits except of phenol and carotenoid. Also interaction effect of drought and abscisic acid was significant for all traits except of phenol and carotenoid content that were the highest in abscisic acid 30 µM/L and drought 30-40 and 50-60 percent field capacity increase antioxidant activity 47.56 and 53.93 percent and 55.20 and 65.72 percent soluble carbohydrate, respectively. abscisic acid 30 µM/L spray and drought 30-40 increase proline 120.17 percent. Also, the highest RWC amount (78.74 percent) from interaction abscisic acid 30 µM/L and drought 90-100 percent field capacity.

Generally, abscisic acid 30 µM/L application and drought 30-40 and 50-60% field capacity Introduces the best treatment, due to the lower consumption of water and the use of abscisic acid in stress conditions, higher levels of abscisic acid can be achieved in inducing drought tolerance.

In order to evaluate the effect of Benzyl Adenine (BA) on qualitative characteristics and shelf life of plum fruits CV “Gold Drops”, an experiment was conducted as a factorial based on randomized complete block design with three replications. In this experiment different concentrations of BA (0, 50, 75, 100 and 125 mg L-1) were applied as a foliar application. After harvesting, fruits were stored at 0.5-1 °C and 90% relative humidity for 6 weeks. Fruit characteristics including weight loss, firmness, titratable acidity, soluble solids, pH, ascorbic acid, antioxidant capacity, phenolic and total flavonoid content, were measured once a week at Tabriz University, Tabriz, Iran. The results showed that effects of BA treatments and storage time were significant in all traits. The lowest percentage of weight loss was found at 125 mg L-1 BA in the first week of storage. The highest and lowest content of TSS were obtained at 125 mg L-1 BA during the six weeks of storage and control treatment in the first week, respectively. The amount of ascorbic acid gradually reduced during storage and the lowest content was found at the end of storage. The highest phenol content of fruit was occurred in 125 mg L-1 BA in the 2nd week and the lowest one in control at the 6th week of storage. According to these findings, BA spraying can bear positive effects on postharvest quality sustainment and shelf life of plum fruit.

In this study, the variation between five populations (Kaleybar, Azarshahr, Urmia, Naghadeh and Doroud) of Iranian Watercress were investigated based on morphological traits and biochemical characteristics such as total antioxidant capacity, total phenol, total flavonoid and vitamin C. The results showed that there was significantdifferenceamongpopulations for all traits except stem diameter. According to the results, Kaleyber (East Azerbaijan) and Urmia (West Azerbaijan) accessions exhibited the highest and the lowest antioxidant capacity, respectively. The results of the correlation coefficient indicated that, leaf length had significantly positive correlation with some characteristics such as leaflet length, internode distance, stem diameter, total phenol and total flavonoid, and total phenol and total flavonoid with antioxidant capacity. Factor analysis showed that the first forth principle components explained 84.69% of the variation. The results of cluster analysis showed, studied accessions were divided into three sub-clusters, which indicates the diversity among accessions is high. There was a great difference between Kaleybar and Azarshahr accessions based on cluster analysis. The obtained results showed that there was high diversity between watercress populations based on morphological and biochemical traits. Also, watercress has a high level of antioxidant activity and Kaleybar population may be considered as the population with the highest antioxidant activity among tested populations.

The present study was done to investigate the correlation between biochemical changes of grafted tree fruits and rootstock fruits in Gorgan university of agricultural science and natural resources in 2012-2013. For this purpose، the antioxidant activity and the total content of phenol and flavonoid on four rootstocks such as Yuzu (Citrus junos)، Shelmahalleh (Citrus sinensis var. shel mahalleh)، Citrumelo (Citrus paradisi X Poncirus trifoliate)، Sour orange (Citrus aurantium) and Italian and Salustiana grafted tree were studied in skin and flesh of fruits. This research was done as a factorial experiment based on completely randomized design with three replications. The result showed that the measured parameters were significantly influenced by cultivar، rootstock and tissue. The highest amount of total phenol (21. 38 mg/gDM) was recorded in Italian skin on Shelmahalleh rootstock. The most antioxidant activity (85. 71 percent) was produced in the skin of Citrumelo rootstock. The maximum content of total flavonoid (0. 337 mg/gDM) was observed in the skin of Salustiana on Yuzu rootstock. The investigation indicated that the total phenol accumulation ability of rootstock fruit influences the antioxidant activity of the grafted tree fruits with a positive correlation Although there was significant differences between antioxidant compounds of grafted tree fruits with fruits of their rootstocks، but there was no relationship between them. It seems this was due to a combination of physiological characteristics of each group (grafted or not) of fruits.