مجله علوم باغبانی ایران
سال پنجاه و چهارم شماره 1 (بهار 1402)

Applying the Dickson quality index (DQI) is an efficient but destructive and time-consuming method for predicting sapling quality in nurseries.Fast and low-cost prediction of the quality, establishment, and growing strength of fruit tree saplings in the orchard through the identification of morphological characteristics, which are so highly correlated with this index, is necessary for different stages of sapling production.To evaluate the relationship between the morphological characteristics in peach and nectarine saplings, bare-root saplings of 16 commercial cultivars with three replicates from 10 nurseries, located in four provinces, were studied. The samples provided from two types of non-certified sapling, grafted on the seedling rootstocks, and certified sapling on the vegetative rootstocks during the transplanting seasons of 2020-2021. Sapling height, diameter above grafting line (DAGL), root length, number of roots and branches, shoot and root fresh and dry weights, height to diameter ratio, and DQI were evaluated, and simple correlations between them were estimated. The correlation coefficients were broken down into direct and indirect effects through path analysis, with DQI as the dependent variable.The results showed that the average DQI for non-certified saplings, produced in different climates, was 14. The higher values were observed in areas with more than 3100 AGDD. In certified saplings, DQI reached to 47. Based on the results of the path analysis for DQI evaluation, the highest direct effect was related to the DAGL.DAGL is the most efficient index in the quality assessment of the saplings, due to having the highest correlation with the DQI and most of the morphological traits.

Solidago virga-urea L. is a valuable medicinal plant that has anti-inflammatory, antimicrobial, antispasmodic, diuretic and analgesic effects. In order to evaluate the phenolic and flavonoid compositions in different organs extract (rosette leaf, stem leaf and flower) and also in extracts obtained from different growth stages (before bloom, first bloom, full bloom and after bloom) of S. virga-urea L.'Phasa F type', two separate experiments were conducted in the form of a randomized complete block design with three replications. The experiment carried out in the Research Institute of Plants and Medicinal Raw Materials of Shahid Beheshti University of Tehran in 2019. Phytochemical properties including total phenol content, total flavonoids and leiocarposide content were measured by Folin–Ciocalteu, Aluminum Chloride method and high performance liquid chromatographic analysis, respectively. The results showed that among different organs, the highest amount of phenol (29.36 mg GAE.g-1 dry weight) was in flowers, flavonoids (8.63 mg RUT. g-1 dry weight) in rosette leaves, and leiocarposide (5.17 mg.g-1 dry weight) in stem leaves. Among the growth stages, the highest total phenol (28.84 mg GAE.g-1 dry weight) and total flavonoids (7.95 mg RUT. g-1 dry weight) were obtained in the full bloom stage, while the highest amount of leiocarposide (9.65 mg.g-1 dry matter) obtained before blooming. According to the results obtained from this study, the best organ and harvest time for having high amounts of total phenol, total flavonoids or leiocarposide can be chosen based on pharmaceutical and food industries requirements, in the climatic conditions of Tehran.

In order to investigate the role of nutrients on yield and quality of two commercial cucumber cultivars, Royal and Hike, the effect of poultry manure at levels of 0, 6, and 12 tons per hectare and chemical fertilizers in four different combinations including the one-time application of 50 kg of urea without micronutrient fertilizer; one-time application of 109 kg ammonium sulfate without micronutrient fertilizer; application of urea, phosphorus, and potassium fertilizers as well as complete micronutrient fertilizer according to soil test; and ammonium sulfate, phosphorus, and potassium fertilizers as well as complete micronutrient fertilizer according to soil test, were studied at three harvesting time. Total yield increased in both cultivars by using fertilizers consisting of poultry manure in the amount of 6 tons per hectare in combination with urea, phosphorus, potassium, and complete micronutrient fertilizers based on soil tests. With increasing poultry manure, the quantity of nitrate accumulation increased, but it was below the allowed threshold in all treatments. In most treatments, tissue firmness in the first and second harvests was higher than in the third harvest and its amount decreased with more nitrogen application. In the Hike cultivar, at all levels of chemical fertilizers, the amount of chlorophyll accumulation in the first and third harvests was higher than in the second harvest. The green color index in the Royal cultivar increased with the application of ammonium sulfate and poultry manure fertilizers. In total, the consumption of six tons of poultry manure with chemical fertilizers based on soil tests and also foliar application of the micronutrient fertilizers improved the yield and quality of cucumber fruit..

This study was conducted to evaluate the morpho-physiological and pomological traits of 21 peach cultivars/genotypes under the Mashhad climatic conditions, during two years (2017-2019), based on a randomized complete block design with three replications. The results indicated significant differences between cultivars and genotypes in terms of morphological, pomological, and qualitative traits. The results showed that ‘Early-Red’ and ‘Vizivo’ were among the early flowering genotypes with a long flowering period (20 days). ‘Baby Gold-5’ and ‘PMsh-5’ were the earliest-ripening, and ‘PMsh-2’ and ‘PMsh-4’ were the latest-ripening genotypes. ‘Dixie Red’ and ‘PMsh-5’with 1.85 and 1.77 m3 respectively had the highest volume of the crown of the tree. ‘J.H.Hale’ had the highest fruit weight with an average of 148.92 g, while ‘Apago’, ‘Early-Red’, and ‘PMsh-5’ had the lowest fruit weight. ‘PMsh-1’, ‘Vizivo’, ‘PMsh-6’, and ‘Sorkho-Sefid Mashhad’ cultivars and genotypes had the highest fruit length, width, and shape index and placed statistically in the same group with ‘J.H.Hale’ cultivar. ‘Sorkho-Sefid Mashhad’ cultivar showed 59.1% more yield efficiency, compared to the control cultivar (‘J.H.Hale’). The highest yield efficiency belonged to ‘Baby Gold-5’, ‘PMsh-3’, ‘Suncrest’, and ‘PMsh-8’. The lowest acidity achieved in ‘Apago’, ‘Shasta’, and ‘PMsh-8’. ‘Sorkho-Sefid Mashhad’, had the highest TSS content, which was increased by 3.68% compared to the control cultivar (‘J.H.Hale’). ‘Apago’, ‘PMsh-1’, ‘Shasta’, and ‘Sorkho-Sefid Mashhad’, compared to ‘J.H.Hale’ cultivar, had higher flavor index, 16.17, 27.25, 26.29 and 26.67%, respectively. In general, based on the studied traits, ‘Sorkho-Sefid Mashhad’, ‘Vizivo’, ‘PMsh-1’, and ‘PMsh-6’ are recommended as promising cultivars and genotypes under Mashhad climatic conditions.

The use of modifiers in drought stress conditions is an optimal and low cost strategy and understanding the different characteristics of the plant in these conditions leads to achieve appropriate production management methods. The main aim of this study was to investigate the role of salicylic acid concentrations (0, 0.5, 1 and 2 mM) in increasing the tolerance of physalis (Physalis peruviana L.) to deficit water stress in three levels (control, 85 and 75% of the field capacity), which was done in the form of a factorial experiment based on a completely randomized design with 3 replications. The results showed that deficit water stress reduced relative water content (RWC), gas exchanges and stomatal characteristics in the plant. Deficit water stress also affected the activity of antioxidant enzymes, the amount of electrolyte leakage and malondialdehyde caused the amount of these characteristics to increase. Salicylic acid application in this study, reduced the negative effects of stress. According to the obtained results, the length and width of the stomatal guard cell decreased and the stomatal density enhanced under deficit water stress conditions. The amounts of stomatal conductivity, transpiration, carbon dioxide in stomatal chamber (INT Co2), as well as photosynthesis rate showed a decreasing trend at 85% and 75% of field capacity. The highest photosynthesis rate belonged to foliar application of salicylic acid at concentration of 1 and 2 mM. Hence, for the cultivation of physalis in arid and semi-arid regions, irrigation levels of 95% and 85% of the field capacity along with the application of salicylic acid in concentrations of 1 and 2 mM can be suggested, while the irrigation level of 75% FC is not recommended due to the negative effect on the measured parameters.

The present research was conducted to investigate the efficacy of preharvest NaHS application as foliar spraying on the quality and antioxidant capacity of kiwifruits cv. Hayward during cold storage. In the present investigation, the effects of a preharvest treatment with H2S donor NaHS in four levels (0, 0.5, 1 and 1.5 mM) at 110, 125, and 140 days after full bloom on nutritional quality and antioxidant capacity of kiwifruit (Actinidia deliciosa 'Hayward') were evaluated during 90 days of storage at 1 °C and 90% relative humidity. Sampling was done to measure the desired traits during four periods of 0, 30, 60 and 90 days after storage. The results showed that NaHS treatment had a significant effect on the evaluated traits. At the end of 90 days of storage, NaHS treatment prevented fruit weight loss and maintained fruit firmness in comparison to the control. The percentage of electrolyte leakage and the amount of accumulated malondialdehyde (MAD) in all concentrations of NaHS was lower in comparison to the control. Preserving ascorbic acid content and increasing the activity of phenylalanine ammonialyase (PAL) lead to higher production of total phenol and flavonoids and improve the antioxidant capacity of fruits. NaHS treatment decreased the activity of polyphenol oxidase in comparison to the control. NaHS at 1.5 mM showed the best effect among the applied treatments. According to the obtained results, this concentration can be recommended as a suitable treatment to maintain the quality of kiwifruit cv. Hayward.

In order to determine cold requirements for flower induction (vernalization), the adult bulbs of Ghermez Azarshahr and Sefid Qom onion cultivars were studied in four time periods (two, four, six and eight weeks) and three temperatures (5, 10 and 15 °C) in a factorial experiment based on a completely randomized design with three replicates. Scaning electron microscope (SEM) was used to determine swelling of reproductive meristem (meristem dome) after applying the treatments. Also, the temporal expression patterns of flowering integrator gene (AcFT2) were analyzed in cv; Ghermez Azarshahr, using Real-Time PCR. According to obtained results, the maximum meristem inflation of Sefid Ghom was observed in 10 and 15 °C, while in Ghermez Azarshahr at 5 °C. Bulbs showed the lowest meristem inflation (30.53%) after 2 weeks of cold storage, and with increasing vernalization time, up to 6 weeks, the meristem inflation (75.35%) increased. The highest relative expression of AcFT2 was observed in the Ghermez Azarshahr after 6 weeks of cold storage at 5 °C, which coincides with meristem inflation results. Ultimately, the best vernalization condition were determined as 6 weeks cold storage at 10 ° or 15 °C for Sefid Ghom and 5 °C for Ghermez Azarshahr.

Tomato is the second most important vegetable in the world after potato, which is rich in minerals and vitamins and has a special place among vegetables, agricultural and commercial economy, although one of the postharvest problems of this product is its high wastes. In 2021, an experiment was conducted to study the quality and storage life of ‘Sena’ cultivar of tomato by application of chitosan, vanillin and acetic acid treatments in the postharvest laboratory of department of horticultural sciences and engineering in Vali-e-Asr University of Rafsanjan. The statistical design of the experiment was a factorial in the form of a completely randomized design. The first factor included the control (distilled water), chitosan 1% (Chit), acetic acid 1% (AA), vanillin 1% (Van), and a combined treatment (AA1%+Van1%+ Chit1%), while the second factor comprised the storage time during 3 storage periods (7, 14 and 21 days) at a temperature of 4±1°C and relative humidity of 85±5%. The results of the experiment showed that acetic acid prevented ionic leakage, microbial contamination, weight loss and maintained firmness. Vanillin treatment kept the fruit firmness during storage up to two times and prevented weight loss (3%) and ion leakage (14%), compared to the control. The lowest content of malondialdehyde, pectin methyl esterase activity, and microbial activity were observed in vanillin. In general, among the investigated treatments, vanillin, due to its antioxidant properties, performed more impressively in the preservation of tomato products than other treatments, and in the last period of storage samples treated with vanillin had the highest score. The vanillin treatment best preserved the evaluated characteristics of tomato fruit and is recommended for the tomato storage process. The treatment of acetic acid as a chitosan solvent was evaluated separately and this application led to the prevention of ionic leakage, microbial contamination, weight loss and maintaining firmness. With regard to results obtained from this research, chitosan and combined treatment had destructive effects on tomatoes, therefore the use of chitosan with low molecular weight is not recommended for the storage of tomato products.

In order to investigate the effect of benzyladenine and a kind of natural phytoncide on various quantitative and qualitative traits related to the marketing value of the strawberry (Fragaria×ananassa Duch.) plant a factorial experiment, based on a randomized complete block design was carried out with three replications in the Albion greenhouse, located in Damavand county. The first factor was benzyladenine (6-BAP) at two levels (0 and 100 mg/l) and the second, phytoncide nanoemulsion (PNE) at three levels (0, 0.75% and 1.5%). Young plants were sprayed twice with 6-BAP during the vegetative growth phase and thrice during the reproductive phase with PNE, which was comprised of the essential oils of Pinus nigra and Picea spp. Application of 6-BAP during the vegetative stage resulted in production of more leaves and higher leaf area. Also, 6-BAP increased crown diameter significantly, compared to control plants, and had a positive effect on all the studied traits at the reproductive stage, as well. This kind of cytokinin improved taste and other quality attributes of the fruits, along with plant yield. PNE was effective on increasing the fruit firmness and longevity. Furthermore, it had a significant effect on delaying the fruit weight loss and maintaining the appearance quality of the fruits for a longer time. Based on the results, taking advantage of 6-BAP and the studied PNE during pre-harvest phase is recommended for improving strawberry fruit characteristics.

In order to investigate the fruit puffiness status and the effect of calcium nitrate spray on quality and puffiness of Satsuma mandarin fruit, two separate experiments were conducted. In the first experiment, the puffing rate of Satsuma mandarin (Citrus unshiu 'Sugiyama') fruit in different orchards in the eastern region of Mazandaran was compared. In the second experiment, the effect of calcium nitrate application as foliar spray on reduction of fruit puffines was examined. The experiment was performed in a commercial orchard, with sour orange rootstock, based on a randomized complete block design, with six treatments and four replications. Treatments included: T1. Control (no Calcium nitrate spray); T2. Calcium nitrate spray in late May; T3. Calcium nitrate spray in mid- June; T4. Calcium nitrate spray in early July; T5. Calcium nitrate spray in late May and mid- June; T6. Calcium nitrate spray in late May, mid- June and early July. The results of the first experiment showed that the percentage of puffed fruits in the orchards of different regions varied from 27 to 46%, and the number of puffed fruits increased significantly from the early of November. The results obtained from the second experiment indicated that calcium nitrate spray in T5 (late May and mid- June) and T6 (late May, mid- June and early July) treatments had a significant effect on puffiness, so that the number of puffy fruits reduced by about 20% compared to the control, but this anomaly did not completely prevented. Also, calcium nitrate spray had a significant effect on Ca concentration in fruits. The highest concentration of Ca in whole fruit, fruit peel and inner skin (albedo) occurred in T5 and T6 treatments. Therefore, calcium nitrate spray is recommended at least 2 times (late May and mid- June) up to a maximum of 3 times (late May, mid- June and early July) in Satsuma mandarin Orchards.