Postharvest physiology
Hamid Soleymani; Mitra Aelaei; Masud Arghavani
Abstract
Introduction
Rose is one of the important cut flowers, which has different types. Extending the vase life of rose-cut flowers is very important in the floriculture industry. Every year, due to the lack of proper storage conditions after harvesting, the efficiency of rose production decreases. ...
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Introduction
Rose is one of the important cut flowers, which has different types. Extending the vase life of rose-cut flowers is very important in the floriculture industry. Every year, due to the lack of proper storage conditions after harvesting, the efficiency of rose production decreases. Therefore, always using materials that help increase the shelf life of cut flowers is valuable. Today, substances that improve the quality of cut flowers are very important. They include materials such as calcium and silver. Nanoparticles are materials with sizes smaller than 100 nanometers. On the other hand, the important role of calcium and silver in improving quality of the cut flowers is interesting for scientists. In this research, the effect of pre-harvest application of calcium nanoparticles along with the post-harvest application of silver nanoparticles on the morpho-physiological characteristics of rose cut flowers (CV: Classic Cezanne) was investigated.
Material and Methods
The current research was carried out during the year 2021 in a commercial rose production greenhouse in Nazarabad city. calcium nanoparticles with different concentrations (0, 5 and 10 mg.L-1) were sprayed on rose bushes every ten days (two months before harvest). After harvesting the flowers and transferring them to the laboratory, silver nanoparticles were added to the flower preservation solution at different concentrations (0, 5 and 10 mg.L-1). After harvesting, the traits (vase life, flower diameter, fresh weight, vase solution uptake, total protein, malondialdehyde and superoxide dismutase) were evaluated on the treated flowers (on days 0, 4, 8 and 12). Experiment was performed as factorial based on completely randomized design, included 9 treatments with 3 replications.
Results and Discussion
Based on the results of analysis of variance of treatment with calcium nanoparticles and silver nanoparticles for the quality of shelf life at the 1% level of Duncan's test, it showed a significant difference. Also, based on the results, the highest amount of vase life is related to the treatment of calcium nanoparticles with a concentration of 10 mg.L-1 with the silver nanoparticle treatment in the time after harvesting was at concentrations of 5 and 10 mg (11 days) and the lowest amount was related to the control treatment (7 days).Vase life increased under the effect of treatment with calcium nanoparticles and silver nanoparticles (10 mg.L-1) and caused an increase of 4 days compared to the control (0 mg.L-1) The treatments decreased the amount of malondialdehyde and also increased the relative amount of absorbed solution, total protein and superoxide dismutase enzyme. Based on the results of this study, calcium and silver nanoparticles improved qualitative traits. The simultaneous treatment of calcium and silver nanoparticles (concentration 10 mg.L-1) compared to the control (0 mg.L-1) caused an increase (14%) in flower diameter, fresh weight (12%), vase solution uptake (46%), superoxide dismutase (21%) and malondialdehyde reduction (37%). Two other important findings emerged from this work: (1) The nanoparticles used in this experiment caused the activation of the enzyme antioxidant system in the treatments (2) The simultaneous treatment of nanoparticles calcium before harvesting and silver nanoparticles treatment after harvesting by activating the antioxidant enzyme system and maintaining the ability to absorb the solution increased the vase life of rose cut flowers. In general, the treatment with calcium nanoparticles at a concentration of 10 mg. L-1 before harvesting and the treatment with silver nanoparticles at a concentration of 10 mg.L-1 after harvesting were the most effective treatments in most traits.
Conclusion
Calcium is one of the most effective factors in increasing the vase life of rose cut flowers. Treatments containing calcium increase absorption of vase solution uptake. The treatment of calcium nanoparticles increases the total protein and superoxide enzyme compared to the control, so that the simultaneous use of silver and calcium nanoparticles increases the vase life of rose-cut flowers compared to the control. Calcium probably activated a chain of reactions by activating the message transmission system and caused the expression of genes involved in the antioxidant system of the samples. silver nanoparticles by affecting the absorption of vase solution uptake and reducing the amount of malondialdehyde and increasing the total protein and superoxide dismutase enzyme compared to the control, increase the vase life of cut flowers. According to the results obtained from the present research, it can be concluded that use of calcium nanoparticles with silver nanoparticles had great effects on most of traits in compared to control treatment. The use of calcium nanoparticles with silver nanoparticles improves the vase life conditions by increasing water uptake and consequently increasing the relative fresh weight.
Ornamental plants
Afsaneh Hooshmand; Mitra Aelaei; Masud Arghavani; Fahimeh Salehi
Abstract
Introdaction
Heavy metals are one of the most important environmental contaminants, particularly in soil and water sources. Mining and metal mining activities are major factors in soil contamination and generally surface soil around mines contain high amounts of these metals. Lead (Pb) is one ...
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Introdaction
Heavy metals are one of the most important environmental contaminants, particularly in soil and water sources. Mining and metal mining activities are major factors in soil contamination and generally surface soil around mines contain high amounts of these metals. Lead (Pb) is one of the heavy metals and important pollutant in arid ecosystem. The use of plants to remove contaminated soil or phytoremediation is an economical method. Today, due to increasing the pollution of soil sources and resultant problems, identification of the resistant plant species against soil pollution is essential. Using lead-contaminated soils requires their decontamination and improvement. There are different methods to remove these pollutions, one of them is the use of phytoremediation to remove pollutants from water and soil or to reduce them. Among the plants that as an ornamental plant can have a covering role in the green space and also perform the work of phytoremediation is the ornamental cabbage plants (Brassica oleracea L.). In this regard, this study was conducted with the aim of investigating the effect of lead heavy metals and the use of brown algae (Polycladia indica) and spirulina (Arthrospira platensis) as biofertilizers on ornamental cabbage plants in the direction of plant treatment. In addition, due to the presence of polysaccharide compounds such as carrageenan and alginate in the cell wall, algae (seaweeds) have a higher ability to absorb many heavy metals.
Materials and Methods
The experiment was conducted as factorial based on a completely randomized design in 2020 at the research greenhouse of Zanjan University. The studied factors including lead from lead nitrate source Pb(No3)2 with three concentrations (0, 25 and 50 mg/kg) were applied to the potting soil in four replications in two stages with an interval of two weeks. The second factor was included no algae, brown algae (Polycladia indica) and spirulina (Arthrospira platensis), which occurred in four replications. The measured traits included morphological traits: number of leaves, leaf surface index. Wet and dry root weight, and physiological traits included total chlorophyll content, total leaf antioxidant, peroxidase enzyme, glycine betaine, malondialdehyde, and leaf lead and phosphorus content. Data analysis was performed using SAS software and means were compared by LSD method.
Results
The results of the variance analysis showed that different levels of lead and the application of algae had a significant effect on the number of leaves per plant, leaf area index, weight, and drying of roots, total chlorophyll, and antioxidants. Moreover, the interaction effect was significant for leaf area, root fresh and dry weight, antioxidants, and leaf lead content. The simple effect of lead at p≤0.01 significantly affected glycine betaine, malondialdehyde, and leaf phosphorus. When comparing the average mutual effects of lead and algae application, it was found that the treatment with no use of lead and spirulina algae resulted in the highest weight and dry weight of the root, with an average of 11.19 and 3.625 grams, respectively. Additionally, despite the decrease in dry weight of the root due to increased lead concentration, using algae, especially for ornamental cabbage (Brassica oleracea L.), increased the dry weight of the root. The presence of natural plant hormones, organic substances, carbohydrates, fiber and amino acids in algae accelerates rooting, reduces stress caused by heavy metals and absorbs more water due to the presence of o developed root system. Also according to the results of comparing the amount of leaf lead with increasing lead, algae as an auxiliary factor can reduce the amount of uptake in the plant. Leaf phosphorus was also significant due to the simple effect of lead and algae. The highest amount of phosphorus with an average of 0.56% was observed in spirulina and the lowest with 0.48% was observed in control.
Conclusion
In general, due to the toxicity of lead metal even in low concentrations, sufficient attention should be paid to the sources of this pollutant entering the environment. In this study, the effective parameters on the uptake of heavy metal lead from the soil by spirulina and brown algae were investigated. The findings of this study indicate that the ornamental cabbage plant is capable of sustaining its growth in the presence of lead and has a high resistance to this heavy metal while simultaneously absorbing it from the soil. Furthermore, the addition of algae as an auxiliary factor can improve the growth of ornamental cabbage under adverse conditions. Therefore, it is recommended that this plant be further examined for its potential to absorb other heavy metals.
Postharvest physiology
Mahshid Ghafouri; Farhang Razavi; Masud Arghavani; Ebrahim Abedi Gheshlaghi
Abstract
Introduction Nowadays, the application of chemical compounds is limited due to their harmful effects on human and the environment health. The benefits of seaweeds as sources of organic matter and fertilizer nutrients have been known to agriculture for centuries, especially in coastal areas extracts ...
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Introduction Nowadays, the application of chemical compounds is limited due to their harmful effects on human and the environment health. The benefits of seaweeds as sources of organic matter and fertilizer nutrients have been known to agriculture for centuries, especially in coastal areas extracts of these seaweeds have been used for decades as foliar- and soil-applied treatments in crop production systems due to the presence of a number of plant growth-stimulating compounds. Unlike chemical fertilizers, extracts derived from seaweeds are biodegradable, non-toxic and non-hazardous to humans, animals and birds. Therefore, it is required to find a safe compound that is utilized in the postharvest technology of fruit and vegetables. Pre-harvest application of nutrient solutions such as seaweed increases the quality and quantity of crop and also enhance their storage life and marketability. Various researchers reported that aqueous extracts of seaweed increased the yield and quality of tangerine and orange, strawberry, grape, apple, and watermelon fruit. Thus, the aim of the current study was to investigate the effect of pre-harvest foliar application of Seaweed extract on quality and quantity values, antioxidant properties, and storage life of kiwifruits.Material and Methods This experiment was carried out on 10-year-old kiwifruit vines, in a commercial orchard located in Gilan Province. Vines were selected with uniform size in terms of growth, yield and fruit load, then sprayed with seaweed extract at four levels of 0, 1, 2 and 3 g.l-1 as a foliar spray and control vines only received water. Foliar spraying was performed in three stages, (110, 125 and 140 days after full bloom stage) and Tween 20 was used as a surfactant. This experiment was designed as factorial based on randomized complete block design with three replications. The fruits were harvested in November with soluble solids content (TSS) of 6.5-6.2% and then transferred to the post-harvest physiology laboratory of the University of Zanjan. The treated fruits were stored for 90 days at 1 ° C with 90% RH. Sampling was done at harvest time and after 30, 60 and 90 days of storage and some quantity and quality traits such as weight loss, tissue firmness, TSS, ascorbic acid, total phenol and flavonoids, antioxidant capacity and the activity of superoxide dismutase (SOD) and phenylalanine ammonia-lyase (PAL) enzymes were evaluated.Results and Discussion The ANOVA results showed that seaweed extract, storage time, and interaction of seaweed extract × storage time had a significant effect (p≤0.01) on evaluated traits. All treatments maintained the antioxidant capacity, total phenol and flavonoids content and PAL activity at a higher level compared with control. The amount of fruit tissue firmness, TA and ascorbic acid decreased by increasing the storage time, and at the third month of storage, the lowest amount was observed in the control fruit. Also, comparing the interaction of the mean of treatments and storage time showed that pH, weight loss, TA, TSS, antioxidant capacity, total phenol, flavonoids and PAL enzyme activity increased by increasing the storage time. At the end of the storage time, the highest level of TSS, weight loss and pH were observed in the control fruit. The lowest antioxidant capacity (48.14 %) was observed in the control treatment at harvest time and the highest antioxidant capacity was observed in 3 levels of brown algae extract treatment at the end of storage period. Comparison of means showed that at the first 30 days of storage, the highest PAL enzyme activity was observed in the treatment of 3 g / l of brown algae. PAL enzyme activity significantly increased after the experiment. At the end of storage period, the lowest PAL enzyme activity was observed in control fruit. Treatment of 3 g / l brown algae had higher PAL activity. PAL, as a key enzyme in phenylpropanoid metabolism, catalyzes the conversion of phenylalanine to trans-cinnamic acid, which is the first step in the biosynthesis of phenylpropanoids and leads to the production of secondary metabolites such as lignin, phytolaxoids, and flavonoids. The direct and positive relationship of this enzyme with the synthesis of phenols and flavonoids has been discovered in the fruits of blood orange, strawberry and blueberry. The results of the comparison of the mean showed that the total phenol and flavonoids increased by increasing the storage time. The lowest phenol (23 mg GAE.100 g-1 FW) was observed in control fruit at harvest and the highest (8.88 mg GAE.100 g-1 FW) content of total phenol was observed in 3 levels of brown algae extract at the third month of storage. Plants release phenolic compounds in response to some messenger compounds that play an important defense role. Studies show that there is a positive relationship between total phenol content and their antioxidant activity. Flavonoids are also polyphenolic compounds and are the most important secondary compounds of plants. Under oxidative stress, in plants, the activity of propanoid pathway increases, especially the pathway of flavonoids biosynthesis. Flavonoid compounds are abundant in plants and show antioxidant activity. Seaweed extract enhances the antioxidant capacity of the fruit and thereby inhibits oxygen-free radicals Treatment of 3 g/l seaweed extract had the best effect among the treatments applied in maintaining firmness, fruit weight loss, TA, antioxidant capacity, total phenol and flavonoids and PAL enzyme activity. All three levels of seaweed extract increased the amount of total phenol, flavonoids and antioxidant capacity all over the storage time, but no significant difference was observed among the treatments levels. Based on the results, the application of 3 g/l seaweed extract effectively increased the antioxidant capacity and PAL enzyme activity during 90 days of storage time. As a result, seaweed extract treatment had positive effects on maintaining the quality and increasing the shelf life of kiwifruit during 90 days of storage.ConclusionSeaweed extract is one of the natural compounds and compatible with human health and nature has medicinal and nutritional value that can increase the shelf life and maintain fruit quality in the postharvest period. In summary, foliar application of seaweed extract has a significant effect on fruit firmness, total soluble solids, total acid, vitamin C, phenol and total flavonoids, total antioxidant activity and the enzyme phenylalanine ammonialyase. The appropriate treatment for kiwifruit cultivar ‘Hayward’ is introduced. Among the applied treatments, 3 g/l of seaweed extract had the best effect on firmness (40.40%), fruit weight loss percentage (41.87%), titratable acid (25.37%), vitamin C (33.26%), antioxidant capacity (26.70%), total phenol (81.17%), total flavonoids (103.67%) and PAL enzyme activity (153.75%) compared to the control in 90 days of storage.
