Growing vegetables
Farzad Abdollahi; Alireza Motallebi-Azar; Gholamreza Gohari; Bahram Dehdar; Amir Kahnamoii; Fatemeh Shariat
Abstract
IntroductionGrapheneis one of the new carbon nanomaterial that has unique physical properties and potentially important biological applications. Nanosheet Graphene Oxide has shown great potential to improve plant performance in various areas. Microtuber production technology is also used as a tool to ...
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IntroductionGrapheneis one of the new carbon nanomaterial that has unique physical properties and potentially important biological applications. Nanosheet Graphene Oxide has shown great potential to improve plant performance in various areas. Microtuber production technology is also used as a tool to reduce the time needed to produce economic plant resources, increase the quality of seed tubers, and produce microtubers throughout the year. The aim of this study was to evaluate the effect of Nanosheet Graphene Oxide on the improvement of micropropagation and microtuberazation in potato var. Agria under in vitro conditions. Materials and MethodsSingle node explants obtained from in vitro virus-free plantlet (maintained in tissue culture laboratory, Department of Horticultural science, University of Tabriz) were cultured into modified Murashige and Skoog (MS) medium containing four concentrations of Nanosheet Graphene Oxide (0, 25, 50 and 75 mg/L) carried out in the completely randomized design (CRD) with four replications and kept at 25±2 degree centigrade and a photoperiod of 16 hours of light. The proliferation traits such as leaf length, leaf width, plantlet fresh weight, number of leaves and shoots were recorded. Then, single node explants were transferred to Murashige and Skoog (MS) medium with four concentrations of Nanosheet Graphene Oxide (0, 25, 50 and 75 mg/liter) and kept for two months in complete darkness and at 18±2 ºC and microtuber production indices such as microtuber number, diameter, length and weight, microtuberization percentage, shoot length, microtuber with dormancy were measured. Results and DiscussionThe results of analysis of variance showed that different concentrations of Nanosheet Graphene Oxide had a significant effect on all traits in proliferation and microtuberization stages. Among different levels of Nanosheet Graphene Oxide, application of 75 mg/L showed the best response for leaf length, leaf width, and plantlet fresh weight, followed by 50 mg/L for the number of leaves and shoots, and lastly, 25 mg/L for shoot length. At a concentration higher than 50 mg/L (75 mg/L graphene oxide), the number of leaves not only remained constant but also showed a decreasing trend. Effect of different NGO concentrations on the shoot length showed that there was no significant difference between different concentrations of NGO and the shoot length remained constant, but the difference between the control treatment and NGO was significant. The maximum shoot length was obtained at a concentration of 25 mg/l NGO. The different concentrations of NGO had significant effect on all microtuberization traits at 1% probability level. Mean comparison results for different concentrations of NGO showed that the highest value of the microtuber length, diameter and number were obtained at 25 mg/liter NGO. However, all microtuber traits were not increased at above 25 mg/liter NGO. With the increase in NGO concentrations, the yield of microtuber weight and microtuberization rate remain constant, and it is also possible that these traits will decrease significantly with the increase NGO concentration. The highest yield of microtuber weight and microtuberization rate were obtained at the 25 mg/L NOG, and higher concentrations did not increase them. There was a significant difference between different concentrations of NGO and the control treatment in the number of lateral shoots, so that the maximum number of lateral shoots was obtained at a concentration of 25 mg/L of NGO. Also, concentrations above 50 mg/L of NGO had less effect on the number of lateral shoots and with increasing concentration, the number of shoots decreased significantly. The maximum microtuber weight was obtained at high concentrations of NGO. In other words, with the increase of NGO concentration, the microtuber weight increased, and the most effective concentration was 75 mg/L of NGO for this trait. Although all concentrations of NGO are favorable for this purpose, it is possible that the concentration of 25 mg/l is the most NGO concentration. ConclusionThe results of this research showed that the of 50 and 75 mg/L of Nanosheet Graphene Oxide were the best concentrations micropropagation and microtuberization. 25 mg/L of Nanosheet Graphene Oxide was most efficient concentration . Although these experiments were performed without the use of growth regulators, the addition of Nanosheet Graphene Oxide to the medium increased micropropagation and microtuberization. Therefore, Nanosheet Graphene Oxide can be used as a tool for efficient micropropagation and increasing the quantity and quality seed tubers.
Postharvest physiology
Fahime Nasr; Vali Rabiei; Farhang Razavi; Gholamreza Gohari
Abstract
Introduction
Persimmon (Diospyros kaki Thunb.) is an important fruit that is consumed due to high nutritional, desirable taste and flavor. Unfortunately, most persimmon fruit producers do not use the suitable technology to preserve the fruit quality, consequently, marketing their product at lower ...
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Introduction
Persimmon (Diospyros kaki Thunb.) is an important fruit that is consumed due to high nutritional, desirable taste and flavor. Unfortunately, most persimmon fruit producers do not use the suitable technology to preserve the fruit quality, consequently, marketing their product at lower prices. The fruit of Karaj cultivar is one of the best and highest quality cultivars in Iran but this fruit is sensitive to chilling injury and shows drastic softening and reduced nutritional value as chilling damage. Appliacation of effective treatments for reducing chilling symptoms and preserve quality can lead to the increase of shelf life in this fruit. Ascorbic acid is an important nutrient that it is required for the functioning of several enzymes and is important for immune system function. It also functions as an antioxidant. Recently this treatment has gained much attention for use as an environmentally friendly technology for the maintenance of postharvest quality of many horticultural crops. In this regard, the aim of the present study was to assess the effect of ascorbic acid and storage time on the postharvest life of persimmon fruit.
Materials and Methods
Persimmon fruit (cv.‘Karaj’) was first harvested at physiological maturity stage from a commercial orchard in Karaj city, then immediately transported to the postharvest laboratory at University of Zanjan. Fruit selected for uniformity of size, shape, color and free from disease or mechanical damage. The treatments included ascorbic acid at three levels (15, 30 and distilled water as a control mmol.L-1) and storage time at three levels (15, 30 and 45 day). Fruit was dipped in solution of Ascorbic acid 15 and 30 mmol.L-1 and distilled water (control) for 10 min. After treatment, the fruits were stored at +4°C and 85-90% relative humidity for 45 days. Fruits were sampled during storage after (15, 30 and 45 days) and 24 hours maintaining at room temperature and fruit firmness, weight loss, TSS, TA, vitamin C, total flavonoids, total phenol, soluble tannins, total carotenoids, antioxidant capacity and MDA were measured at the end of each period. Persimmon fruit samples were weighed before and after the storage to calculate weight loss (%) during storage by using the formula of [(weight of fruits before the storage − weight of fruits after the storage)/weight of fruits before storage] × 100. Fruit firmness was determined using OSK 1618 penetrometer equipped with an 8 mm tip at 3 equatorial points, and the results were expressed as kg/cm2, Soluble tannin was measured by using the method of Tiara (1996). Total carotenoid was measured based on wang et al (2006), Total soluble solid (TSS) was measured by using refractometer, Ascorbic acid content was determined by using the method of Jalilimarandi (2000) and Antioxidant activity was evaluated by measuring the scavenging activity of the examined extracts on the 2,2-diphenylhydrazil (DPPH) radical as described by Dehghan and Khoshkam (2012). Statistical analysis was performed using SAS V9 software and the treatment means were separated by Duncan’s multiple range tests.
Results and Discussion
Results showed that all treatments showed significant effect on evaluated traits. All treatments preserved vitamin C and antioxidant activity of fruit compared with control. Ascorbic acid 30 mmol.L-1 significantly preserved firmness, soluble tannin, total phenol, flavonoid, antioxidant capacity. Based on current results that ascorbic acid 15 and 30 mmol.L-1 treatments were the most effective in delaying decrease weight loss by reduced metabolic activity, delayed senescence, and maintained better cellular integrity thereby worked in an integrated manner to reduce fresh weight loss of persimmon fruit. Increasing Ascorbic acid suppressed oxidative damage possibly by quenching hydrogen peroxide and superoxide anion. Therefore, positively correlated with higher membrane integrity and less MDA of persimmon fruit. Ascorbic acid is not only an important nutraceutical compound but also a critical antioxidant that positively eliminates certain reactive oxygen species and preserve antioxidant compounds such as phenol, flavonoid, carotenoid and vitamin C in post-harvest. Ascorbic acid 15 and 30 mmol.L-1 treatments used in this experiment had no effect in changes TSS and total carotenoid. So ascorbic acid can improve effectively the quality and increase shelf life of fresh persimmon fruit in post-harvest.
Conclusion
In conclusion, our research indicates that ascorbic acid could prolong postharvest life of persimmon fruit by maintaining fruit quality attributes. Ascorbic acid treatment significantly is effective in preserving, firmness antioxidant compounds, quality properties and increasing the storage time of persimmon fruit of Karaj cultivar without harmful for human health. Hence, ascorbic acid treatment is a safe and applicable method of increasing the shelf life and preserving the quality in persimmon during cold storage.
