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The beet cyst nematode (BCN) (Heterodera schachtii), and beet curly top virus-severe (BCTV-Svr) (Curtovirus betae) are two important pathogens of sugar beet fields worldwide. Therefore, the reaction of 14 genotypes was separately assessed, using Jolgeh and Sanetta cultivars as susceptible and resistant controls, respectively, in completely randomized design experiments for BCN and BCTV-Svr. Reactions were based on the cyst and egg counts and symptoms severity index. Experiments were performed in the greenhouse of Tarbiat Modares University, Tehran, Iran, and were repeated twice independently. Based on the results of initial experiments, the S1-960090, S1-940324, S1-960294, and S1-960284 genotypes resistant to the BCN were selected for further investigation. Furthermore, the reaction of the four selected genotypes to BCN, BCTV-Svr, and the combination (mixture) of the two pathogens was evaluated by analyzing their growth, physiological, and biochemical characteristics, and virus accumulation. Resistant genotypes showed higher levels of defense-related enzymes such as catalase, guaiacol peroxidase, and polyphenol oxidase, whereas susceptible genotypes exhibited significant reductions in photosynthesis, greenness, and chlorophyll a, b, and carotenoid content compared to non-inoculated and resistant plants. This is the first study conducted to search for dual-resistance sources against two devastating pathogens that frequently occur in the sugar beet-growing regions of Iran. Based on the results of this experiment, genotypes S1-960090 and S1-940324 were identified as resistant to both pathogens and are recommended for breeding purposes.
 

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This project was carried out in order to  Study of possibity of uses from Grape seed extract for prevention of melanosis in cultured shrimp and its instead to synthethic matterial.Treatments including of Grape seed extract processed with 10g/l concentration and control samples. The samples were kept at -18^oC. Chemical and sensory examinations were carried out for a period of six months. No statistically significant difference was observed in peroxide value and free faty acids in test samples compared with the control samples during storage period (P<0.05). No statistically significant difference was observed in thiobarbotouric acid and pH in test and control samples during storage period(P<0.05). TVN )Total Volatile Nitrogen( and trimetylamin factors were decreased in test samples compared with control samples. Statistically significant difference was observed in TVN, moisture and trimetylamin in test and control samples during storage period(P<0.05). No statistically significant difference was observed in colour and melanosis in test samples compared with control samples during storage period(P<0.05). No statistically significant difference was observed in Humidity, protein, lipid and ash in test samples compared with the control samples(P>0.05). Test samples had better quality compared with the control samples. The covered samples had a favorable quality until the end of storage period. But, the control samples had a favorable quality for a period of 20 days.

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Mushrooms have low stability and therefore, use of applied scientific methods to increasing their stability has more important role to increasing product development. In order to study effect of nitric oxide treatment and maintenance time on physicochemical properties of mushroom (Agaricus bisporus) . A factorial experiment using completely randomized design with two concentrations of nitric oxide (0 & 4.5 mM) & 3 replication . In first time, two concentrations : 0 & 4.5 mM SNP (sodium nitroprusside) were prepared and mushrooms were dipped for 10 minutes in the solutions of nitric oxide donor, then packed in polystyrene bags, and stored at 4 ° C for 9 days, and mushroom properties were measured such as: firmness, total phenolics, ascorbic acid rate & activities of polyphenol oxidase in the days of 3, 6 and 9. The treatment of mushroom with nitric oxide significantly maintained quality at the end of the storage , So that mushrooms that containing 4.5 mM concentration nitric oxide compared with control and showed a high level of firmness, , maintained, Total phenol , ascorbic acid and reduce on activities of polyphenol oxidase on the third day in the storage. The results indicated that, the application of nitric oxide may be used as an effective and successful strategy to increase the shelf life of mushroom (Agaricus bisporus) .

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In order to maintain the quality of pistachio fruit and evaluation of fruits color changes and browning an experiment was conducted as block completely randomizes design as factorial with three factors: perharvest polyamines forms applications: putrescine, spermidine, and spermine at 1 mM; chitosan (0 and 1%) and storage periods (0, 20 and 40 days of storage) with three replications on ‘Akbari’ cultivar. In this study fruits and hull water, hull and shell indices, pigments, hull and kernel phenolic compounds, polyphenol oxidase and antioxidant activity were measured. The results showed that hull and kernel phenolic compounds, polyphenol oxidase, antioxidant activity, anthocyanin, hull water, hull color indices were decreased during storage period and perharvested application of polyamines maintained these traits during storage. Among polyamines, putrescine had the highest influence on these traits compared to spermidine and spermine. The results also showed that chitosan application also maintains hull and kernel phenolic compounds, polyphenol oxidase, antioxidant activity, anthocyanin, hull water, hull color indices in pistachio treated-fruits and untreated-fruits with polyamines during storage. The results also indicated that combined application of putrescine and chitosan had the greatest effect on maintaining pistachio characteristics and reducing the percentage of fruits browning during storage. Therefore, according to the results of this study, the use of putrescine with a concentration of 1 mM before harvest following chitosan coating can plays an important role in maintaining the quality of fresh pistachio fruit during storage.

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Pistachio is one of the most important horticultural produce is used both in dry and fresh form. The fresh pistachio is very perishable due to its high respiration, heat production and moisture resulting to short shelf life. Therefore, in order to maintain quality and improve the shelf life of this produce, a factorial experiment with two treatment factors (control, 2 g activated carbon sachets, 4 g activated carbon, 2 g activated carbon impregnated with potassium permanganate saturation, 4 g activated carbon impregnated with potassium permanganate Saturation) and storage time (0, 20 and 45 days) was designed in a complete block with four replications on pistachio cultivar Ahmad Ahaghei. The results showed that different indices of evaluated fruit quality included weight loss, hull firmness, total chlorophyll, lightness, total color changes, antioxidant activity, anthocyanin, hull and kernel phenolic compounds and PPO activity was affected by the treatments. hull firmness, total chlorophyll, lightness, antioxidant activity, anthocyanin, phenolic compounds decreased during storage time but weight loss, total color changes, and PPO activity increased then control and treatments maintained these traits. Among the treatments 4 g activated carbon impregnated with potassium permanganate had the most effective on maintaining the quantitative and qualitative characteristics of this pistachio cultivar.

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In recent years, the use of natural and healthy compounds has been considered as a new method to control chilling and maintain postharvest quality of horticultural products. In this study, for the first time, pomegranate fruits were immersed in L-arginine solution at concentrations of 0, 1 and 2 mM and Its effects on the quality of pomegranate fruits ‘Malas-e-Saveh’ grown in Sari region was evaluated during 120 days in cold storage. Based on the obtained results, the treatment significantly increased the total phenol and antioxidant properties of the fruit compared to the control. Fruits treated with 1 mM L-arginine showed more antioxidant activity compared to the control. Moreover, the activity of antioxidant enzymes (CAT, SOD, APX) as well as PAL enzyme increased accordingly. Whereas, H₂O₂ accumulation and PPO enzyme activity in fruits treated with 1 mM L-arginine were significantly reduced. Based on our results, L-arginine treatment can be used as a useful and practical method to maintain nutritional quality and increase the pomegranate storability due to its safety and effectiveness.

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Riboflavin (vitamin B₂) affects plant growth and development and participates in a variety of redox processes that affect plant defense responses. Two rice cultivars Fajr (improved) and Tarom Mahali (traditional) were foliar sprayed with increasing concentrations of riboflavin (0, 0.5, 1, 1.5 and 2 mM) and subsequently infected by Pyricularia oryzae. Then, leaves were collected at 0, 2, 4, 6 and 8 days after infection and activity of Peroxidase (POD), PolyPhenol Oxidase (PPO), and Phenylalanine Ammonia Lyase (PAL) were measured. Results revealed that lesion size and percentage of infected rice plants in Fajr was higher than Tarom Mahali. In addition, riboflavin-induced resistance was higher in Fajr than in Tarom Mahali due to higher activity of POD, PPO and PAL in Fajr than Tarom Mahali, especially upon exposure of plant to 2 mM riboflavin. The intensity of the bands of peroxidase isoenzymes with low molecular weight was enhanced by increasing concentrations of riboflavin in both rice cultivars, while elevated riboflavin concentration caused the synthesis of three new isoenzymes in Fajr (g, h, i) and one (f) in Tarom Mahali cultivars. It can be concluded that Fajr is more sensitive to infection of P. oryzae than Tarom Mahali. In addition, the activity of POD, PPO, and PAL enhanced intensity of peroxidase isoenzymes bands. Also, the synthesis of new isoenzymes by riboflavin showed that riboflavin-induced resistance was more effective in Fajr than in Tarom Mahali.
 

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In this study, the effect of vine training system and storage time were evaluated on some grape characteristics, such as berry contamination percentage, berry shedding percentage, berry browning rate, titratable acidity, soluble solids, total phenol and the activity of peroxidase, polyphenol oxidase and phenylalanine ammonia-lyase enzymes, in order to maintain the quality of grape during storage time. Factorial experiment was conducted based on completely randomized design with two factors of vine training system (khazandeh, pergola and cordon) and storage time (zero, 20, 40 and 60 days after storage) with three replications during 2018-2019. After transferring the fruits to the cold storage with temperature of +4◦C, relative humidity of 85-90% and storage for two months, some characteristics of grape were examined on different days after storage. The results showed that the effect of storage time on berry browning was significant at the level of 1% probability. Also, the effect of interaction between vine training system and storage time on titratable acidity and on the other measured characteristics was significant at the level of 5% and 1% probability, respectively. In general, the results showed that the cordon training system had the best effect in maintaining the characteristics of grape during the storage period compared to other training methods.
 

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The study was conducted exploit the proteins of the pods of some types of plants, such as Prosopis juliflora pods, that are considered by-products in many countries and considered a good source of protein in the preparation of protein hydrolysers and evaluating their effect on inhibiting brown discoloration of apple slices and compared with anti-browning agents (ascorbic acid, acetic acid, and sodium chloride) when stored in the refrigerator for 0, 5 and 8 days. The chemical composition of the moisture, protein, fat, ash, and carbohydrate of the P. juliflora pods was estimated, then the hydrolysis process was carried out using the enzymes trypsin and papain for 300 minutes. Amino acids and FTIR analysis of protein hydrolysates were determined. Significant changes (p≤0.05) in pH, total soluble solids, and non-significant changes in titration acidity of apple slices treated with protein hydrolysis and anti-browning agents were studied and significantly decreased (p≤0.05) in the activity of polyphenol oxidase until the end of the storage. The brown coloration decreased when treated with protein hydrolysates compared to other treatments, but non-significant changes. As a result, apple slices can be preserved with protein hydrolysers for several days in the refrigerator.
 

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Carrot juice color changes from orange to brown immediately after production. Blanching is a suitable way to preserve and commercialize this product. In this study, an ohmic device was used as a heating source, and polyphenol oxidase enzyme was selected as an indicator of enzyme inactivation sufficiency to color change of carrot juice. Fresh carrot juice was subjected to thermal processing under 3 temperature levels of 70, 80, and 90 degrees of Celsius and 4 time levels of 0, 20, 40 and 60 seconds with a constant voltage of 100 volts and the enzyme inactivation, Brix, pH and color indexes L* , a* and b* were checked. Constant values of reaction rate, activation energy, D-value and Q10   were investigated. The kinetics of inactivation of polyphenol oxidase of carrot juice samples were calculated at 70, 80 and 90 degrees of Celsius. The changes of enzyme inactivation, Brix, pH and a* parameter with increasing temperature and time were significant at 1% probability level by completely random design. The level of enzyme inactivation was also measured by the conventional water bath method and compared with the ohmic method, and the results indicated the greater efficiency of the ohmic method. As the temperature increased, the Brix level increased and the color of carrot juice changed from orange-yellow to orange-red (p≤0.05).