Pomology
Javad Samimi; Yahya Selahvarzi; Ali Tehranifar; Nasser Beikzadeh
Abstract
IntroductionPear (Pyrus communis L.) is a cold-climate fruit tree belonging to the Rosaceae family, and it is native to Western Asia and Eastern Europe. Fire blight disease is caused by the gram-negative bacterium Erwinia amylovora, and it is considered one of the most damaging and harmful diseases in ...
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IntroductionPear (Pyrus communis L.) is a cold-climate fruit tree belonging to the Rosaceae family, and it is native to Western Asia and Eastern Europe. Fire blight disease is caused by the gram-negative bacterium Erwinia amylovora, and it is considered one of the most damaging and harmful diseases in pome fruit trees in cold and temperate regions worldwide. The most sensitive plant organ in pome fruit trees to this disease is flowers. Fire blight disease has five important stages, from initial infection to the final death of the tree trunk. These five stages include blossom blight, fruit blight, leaf blight, main branches, and trunk blight, and finally, root blight. The first and most important stage of pathogenicity in fire blight disease begins in early spring under high humidity, causing the burning and death of the flower. Materials and MethodsThe Rootstock used in this experiment were Dargazi and Pyrodwarf, and the cultivars studied were Koshia and Dargazi. The experiment was conducted in two conditions, orchard and greenhouse. In the orchard, a factorial experiment was carried out in a completely randomized block design with five repetitions. The factors studied were Rootstocks (Dargazi and Pyrodwarf) and cultivars (Koshia and Dargazi). In the greenhouse, a factorial experiment was carried out in a completely randomized design with three repetitions. The factors studied were Rootstocks (Dargazi and Pyrodwarf) and cultivars (Dargazi and Kosha). Gardner scale was used to measure the severity of fire blight infection. In addition, the levels of sucrose, sorbitol, and pH in leaf tissue were measured. The sucrose content in the leaf tissue of Koshia/Pyrodwarf Rootstock increased from day 0 to 6 and reached its highest level (10%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Pyrodwarf base, sucrose levels increased from day 0 to 6 and reached its highest level (8%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Dargazi base, sucrose levels increased from day 0 to 6 and reached its highest level (7%) on the 6th day, then decreased to 4% on the 12th day. The sorbitol content in the leaf tissue of Koshia/Pyrodwarf base increased from day 0 to 6 and reached its highest level (2%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Pyrodwarf Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1.5%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Dargazi Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1%) on the 6th day, then decreased to 0.5% on the 12th day. On the other hand, the pH of the leaf tissue in the Dargazi/Pyrodwarf base remained constant at 6.2 from day 0 to 12 and increased to 7.4 on the 12th day. Results and DiscussionThe rootstock used in this experiment were Dargazi and Pyrodwarf, and the cultivars studied were Koshia and Dargazi. The experiment was conducted in two conditions, orchard and greenhouse. In the orchard, a factorial experiment was carried out in a completely randomized block design with five repetitions. The factors studied were rootstocks (Dargazi and Pyrodwarf) and cultivars (Koshia and Dargazi). In the greenhouse, a factorial experiment was carried out in a completely randomized design with three repetitions. The factors studied were Rootstocks (Dargazi and Pyrodwarf) and cultivars (Dargazi and Koshia). Gardner scale was used to measure the severity of fire blight infection. In addition, the levels of sucrose, sorbitol, and pH in leaf tissue were measured. The sucrose content in the leaf tissue of Koshia/Pyrodwarf Rootstocks increased from day 0 to 6 and reached its highest level (10%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Pyrodwarf Rootstock, sucrose levels increased from day 0 to 6 and reached its highest level (8%) on the 6th day, then decreased to 5% on the 12th day. In the Dargazi/Dargazi Rootstock, sucrose levels increased from day 0 to 6 and reached its highest level (7%) on the 6th day, then decreased to 4% on the 12th day. The sorbitol content in the leaf tissue of Koshia/Pyrodwarf Rootstock increased from day 0 to 6 and reached its highest level (2%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Pyrodwarf Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1.5%) on the 6th day, then decreased to 1% on the 12th day. In the Dargazi/Dargazi Rootstock, sorbitol levels increased from day 0 to 6 and reached its highest level (1%) on the 6th day, then decreased to 0.5% on the 12th day. On the other hand, the pH of the leaf tissue in the Dargazi/Pyrodwarf Rootstock remained constant at 6.2 from day 0 to 12 and increased to 7.4 on the 12th day. The collected data from both orchard and greenhouse experiments were analyzed to determine the effects of Rootstock and cultivar on fire blight resistance. ConclusionThe results showed that the combination of Koshia/Dargaz had higher resistance to fire blight compared to Koshia/Pyrodwarf. Additionally, the pH and carbohydrate content in the leaf tissue of the rootstock affected the growth and proliferation of fire blight bacteria. This study demonstrated varying levels of resistance to fire blight among the studied combinations, indicating significant potential for breeding and improving pear resistance to this disease. The Dargazi cultivar exhibited very high resistance to fire blight in both orchard and greenhouse conditions. Overall, the resistance of the Dargazi rootstock contributed to the resistance of the sensitive Koshia cultivar.
Postharvest physiology
Fatemeh Ahmadi; Mohammad Mehdi Sharifani; Amir Mousavi; Negin Akhlaghi Amiri; Mostafa Khoshhal Sarmast; Khalil Zaynali Nezhad
Abstract
IntroductionExternal and internal quality of citrus such as color, shape and taste increase economic benefit. The vigour of each rootstock causes qualitative and quantitative change and the effective factor on commercial maturity, which is important for gardeners and producers. Considering the characteristics ...
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IntroductionExternal and internal quality of citrus such as color, shape and taste increase economic benefit. The vigour of each rootstock causes qualitative and quantitative change and the effective factor on commercial maturity, which is important for gardeners and producers. Considering the characteristics of the fruit in grafted trees, the present research was conducted with the aim of evaluating the effects of trifoliate orange, Citrange and Citrumelo rootstocks on some morphological, phytochemical and molecular traits of ‘Thomson Navel’ orange fruit. Materials and MethodsThis research was carried out in 2018 at Ghaemshahr Horticultural Research Station, Mazandaran. It was conducted in the form of randomized complete block design (RCBD) of uniform and 10-year-old ‘Thomson Navel’ orange grafted on ‘trifoliate orange’, ‘Citrange’ and ‘Citrumelo’ rootstocks with four replications. The samples were collected at the end of October and were transferred to the research laboratory of Horticulture Department, Gorgan University of Agricultural Sciences and Natural Resources for further research. Measurements were made on the morphological traits, quality characteristics of the fruit, the phenolic compounds of the peel and the pulp of the fruit and relative expression of fruit pulp sucrose phosphate synthase1 gene. Data variance analysis was done using SAS software (version 9.0). Mean comparisons were done with Duncan's multiple range test. Results and DiscussionThe results of analysis of variance showed that the rootstock effect on traits of length-to-diameter ratio, weight and density of ‘Thomson Navel’orange was significant at the five percent probability level (p<0.05) and the fruit length and diameter traits were significant at the one percent probability level (p<0.01). The results of mean comparison showed that the characteristics of length, diameter, length-to-diameter ratio, weight and density of ‘Thomson Navel’ orange at commercial maturity on the trifoliate orange rootstock were more than the two other rootstocks. Due to the early harvest, the density of the fruit was recorded lower than one, so that the highest amount (0.5 g per cm3) was observed in the rootstock of trifoliate orange however it was not significantly different from Citrange rootstock. Based on the results of analysis of variance, it showed that the effect of rootstock on total soluble solids was significant at the level of five percent. Also, the rootstock had a significant effect on titratable acidity, taste index, vitamin C, acidity, EC and total sugar at the level of one percent. However, the amount of vitamin C was higher in the Citrumelo rootstock. The highest amount of acidity and EC belonged to trifoliate orange rootstock and the lowest amount belonged to Citrange rootstock. The highest amount of total sugar was observed in the dwarfing trifoliate orange rootstock, while its lowest amount was recorded in the vigorous Citrumelo rootstock. The highest amount of total soluble solids was observed at the rootstock of the trifoliate orange. The amount of titratable acid in the Citrange rootstock was higher than the other two rootstocks. The taste index was higher in the trifoliate orange rootstock than the other rootstocks. According to the results of analysis of variance, the rootstock effect on the index of total phenol of fruit peel and pulp and total flavonoid of fruit peel was significant at the five percent probability level (p<0.05) and only on the antioxidant activity of the fruit peel at the statistical level of one percent (p<0.01). Also, there was no significant difference in total flavonoid traits and antioxidant capacity of fruit pulp. The highest amount of total phenolic, total flavonoid and percentage of antioxidant activity was found in the trifoliate orange rootstock. Also, between the fruit organs, phenolic compounds were recorded more in the fruit peel compare to the fruit pulp. The peel of orange is more exposed to ultraviolet rays and changes in environmental conditions, Therefore more secondary metabolites accumulate in that part of the plant. The highest relative expression of fruit pulp sucrose phosphate synthase1 gene was obtained in the Citrange rootstock. ConclusionThe vigor of different citrus rootstocks caused the dwarf trees to have a higher accumulation rate of phytochemical indices than the vigorous trees. The trifoliate orange rootstock is suitable for fresh consumption due to the early commercial maturity of the fruit. Fruit peel rich in phenolic compounds is used for medicinal purposes. The technical knowledge from this research will be useful for citrus producers in East Mazandaran.
Ali Tajabadipour; Mohammadreza Fattahi; Zabihollah Zamani; Fatemeh Nasibi; Hossein Hokmabadi
Abstract
Introduction: Spring cold injury is one of the main limiting factors to production and distribution of pistachio. Pistachio is one of the most valuable and exported agricultural crops of Iran. Since, spring frosts results to considerabe damage to this plant, hence, it is important to investigate methods ...
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Introduction: Spring cold injury is one of the main limiting factors to production and distribution of pistachio. Pistachio is one of the most valuable and exported agricultural crops of Iran. Since, spring frosts results to considerabe damage to this plant, hence, it is important to investigate methods for reducing freezing damage. For this reason, selection of rootstocks and cultivars are an important objective in breeding programs. Freezing temperatures (below 0ºC) cause the movement of water from the protoplast to the extracellular space, resulting in the growth of extracellular ice crystals and ultimately, cell dehydration. Plants have developed complex processes to survive and recover from unfavorable conditions. To tolerate cold stresses, plants develop multiple mechanisms, including the accumulation of cryoprotective molecules and proteins, alterations in membrane lipid composition, and primary and secondary metabolite composition, as well as changes in global gene and protein expression Frost affects cell membranes, which become less permeable, and even break, giving rise to the leakage of solute from damaged cells. There is often a good correlation between ion leakage and freezing tolerance (22). Sugars may depress the freezing point of the tissue and act as a nutrient and energy reserve, alter phase properties of membranes in the dry state and act as cryoprotectants to preserve protein structure and function. Other compounds acting similarly are lipids, soluble proteins and free proline (44). Proline seems to have diverse roles under osmotic stress conditions, such as stabilization of proteins, membranes and subcellular structures and protecting cellular functions by scavenging reactive oxygen species (23). The aim of the present study was to evaluate different degrees of sensitivity to low temperatures in different genotypes and ‘Ahmad-Aghaii’ cultivar in relation to physiological and biochemical changes in field conditions.
Materials and Methods: In order to determine the effects of rootstock on pistachio cultivar ‘Ahmad-Aghaii’ under freezing stress conditions, an experiment was carried out as factorial based on a randomized completely design (RCD) with four replications. Treatments consisted of two levels: 1- rootstock genotype (four cold sensitive and tolerant rootstocks) and 2- temperatures (-2 and -4 ºC). The sampling was performed in full bloom stage from apical branches of pistachio cultivar ‘Ahmad-Aghaii’ budded on these rootstock genotypes. The branches in pots contain distillted water treated under -2 and -4 °C for 2 h. After treatment, the chilling index was determined. Flower clusters were used for measuring physiological and biochemical parameters. All determinations were carried out in four triplicates and data were subjected to analysis of variance. Analysis of variance was performed using the ANOVA procedure. Statistical analyses were performed according to the SAS software. Significant differences between means were determined by Duncan’s multiple range tests. P values less than 0.05 were considered statistically significant.
Results and Discussion: The results showed that chilling index was significantly lower in the cold-tolerant rootstocks than cold-sensitive rootstocks at -2 and -4 ºC. Also, Results indicated that electrolyte leakage, hydrogen peroxide (H2O2) and malondialdehyde (MDA) were significantly lower in tolerant rootstocks than sensitive ones. The content of soluble carbohydrate, total protein and proline were significantly higher intolerant rootstocks than sensitive ones. The activity of anti-oxidant enzymes ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and catalase (CAT) in tolerant rootstocks was greater than sensitive rootstocks. The reaction of temperature and rootstock indicated that electronic leakage, proline, H2O2,و and MDA significantly increased in -4 ºC. The activity of anti-oxidant enzymes APX, GPX and CAT decreased in -4 ºC as compared to -2 °C especially in cold-sensitive rootstocks. Some researchers believe that the accumulation of proline is as an index to select the drought-resistance varieties (26, 48). Stated that there was no comprehensive information about the relationship between the accumulation of proline and tension resistance. Research on apricot and peach confirmed the results of the present study because this pattern is also seen in their proline level (26 and 41). While the starch concentration decreases during the dormancy, the amount of proline increases which is in accordance with their results (36).
Conclusions: In this study, the damage of the membrane increased with decreasing temperature. The results showed that the rootstocks could increase the resistance to cold by increasing the amount of soluble sugars, protein, proline and the activity of the antioxidant system in the shoots and leaves of the scion. Regarding physiological and biochemical studies, it was determined that ‘Ahmad-Aghaii’ cultivar budded on cold tolerant rootstocks had higher soluble sugars, total protein, proline and CAT, APX and GPX enzymes activity and had less chilling index, ion leakage, H2O2 and MDA, which indicates less damage to the membrane of the cell and its contents compared with the cultivar 'Ahmad-Aghaii' budding to sensitive rootstocks. Consequently, the findings of this study selected TR1 as the most tolerant rootstock compared to other ones.
Reihane Mesgari; Taher Barzegar; Zahra Ghahremani
Abstract
Introduction: Cucumber is one of the most important vegetable crops for the local consumption and exportation. The use of grafted vegetable seedlings has been popular in many countries during recent years. Growing fruit-bearing vegetables, chiefly tomato, cucumber and watermelon through grafted seedlings ...
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Introduction: Cucumber is one of the most important vegetable crops for the local consumption and exportation. The use of grafted vegetable seedlings has been popular in many countries during recent years. Growing fruit-bearing vegetables, chiefly tomato, cucumber and watermelon through grafted seedlings become a widespread practice worldwide. Grafting is a valuable technique to avoid soil-borne diseases, provide biotic and abiotic stress tolerance, enhance nutrient uptake, optimize water use, and increase fruit yield and quality. Vegetable grafting is a new topic in Iran and there are a limited number of studies on grafted vegetable production. However, attention to grafting by researchers has recently increased. Suitable rootstocks should be identified and characterized for the effective utilization of grafting. The rootstock's vigorous root system increases the efficiency of water and nutrient absorption, and may also serve as a source of endogenous plant hormones, thus leading to increased growth and yield in addition to disease control. In the present study, we investigated the response of two Cucurbita sp. and an Iranian melon as rootstocks for cucumber.
Materials and methods: In order to study the effect of cucurbit rootstocks and grafting method on growth, yield and fruit quality of cucumber (Cucumis sativus cv. Super Dominus), an experiment was conducted as a factorial design in the base of RCBD with three replications in the greenhouse and research farm, University of Zanjan. Treatments were included three rootstocks (Cucurbita moschata L., Lagenaria siceraria and Cucumis melo L.) and ungrafted plants (control) and two grafting method (hole insertion and splice grafting). Seeds were sown simultaneously in plastic pots. For obtaining the same stem diameter of scion and rootstocks, cucumber seeds were planted four days earlier than rootstocks seeds. The seedlings were grown in an environment-controlled greenhouse with 25/20 day/night temperatures. When seedlings reached the first true leaf stage (diameter of the leaf was about 2 cm) the grafting was performed. After grafting, grafted plants were transferred to a mist chamber for post-graft care (>95% RH, 27-30 °C) for 10 days, after which the relative humidity was reduced gradually for acclimatization. After 20 days of grafting, surviving grafted plants and ungrafted plants were transplanted to the field. Common agricultural practices like fertilizer application, insects and disease control were adopted. Vegetative growth, yield and fruit quality were measured. Data were analyzed using the SAS statistical program (SAS Institute Inc., Cary, NC, USA), and means were compared by Duncan’s multiple range tests at the 5% probability level.
Results and Discussion : The result showed that rootstocks had a significant effect on growth indexes. Cucumber was grafted on cucurbita moschata L. rootstock had the highest stem length and leaf numbers, while, the lowest values of plant height, leaf area, leaf number and yield were recorded with grafted plant on melon rootstock. Fruit numbers were significantly influenced by rootstock. The highest fruit number per plant was observed in cucumber plants that were grafted on cucurbita moschata rootstock. The results of the study showed that cucumber grafting on suitable rootstocks had positive effects on the yield. But rootstock had no significant effects on fruit quality like flesh firmness and total soluble solid. The Soluble solid content of fruit was reported to decrease in tomato, cucumber and eggplant due to grafting. chlorophyll content of leaf showed significantly different between grafted and non-grafted plants. The highest amount of leaf area was obtained from non-grafted plants. Grafting methods had no significant difference in growth, yield and fruit quality. Nitrogen and potassium leaf contents of grafted cucumber and ungrafted plants had no significant difference. The interaction between rootstocks and grafting method had no significant effect on yield and the other growth indexes.
Conclusion: Our findings showed that vegetative growth and yield of cucumber were affected by grafting. On the basis of these results, Cucurbita moschata rootstock had the highest effect on growth and yield of cucumber. It may also be concluded that the grafting method had relatively same growth response. Although the cost of a grafted seedling is surely one of the main concerns of growers, especially since grafted seedling costs from three to five times more than non-grafted seedling. However, investigation proved that, on-farm grafted cucumber transplant production can be successful and the results indicate that grafting of cucumber onto cucurbit rootstocks can increase on-farm net returns due to improve growth and yield.
Mahmood Ghasemnejad; Ali Momenpour; Ali Reza Abdolahpour; Ali Reza Sheiykh Eshkevari
Abstract
In this research, the effect of irrigation duration on growth characteristics of Thomson navel orange grafted on three rootstocks was evaluated in Complete Randomized Block Design in Iran Citrus Research Institute. Factors included rootstock in three levels (Poncirus (Poncitus trifoliate), citrange (Citrus ...
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In this research, the effect of irrigation duration on growth characteristics of Thomson navel orange grafted on three rootstocks was evaluated in Complete Randomized Block Design in Iran Citrus Research Institute. Factors included rootstock in three levels (Poncirus (Poncitus trifoliate), citrange (Citrus sinensis Poncitus trifoliata) and sour orange (Citrus aurantium)) duration of irrigation in four levels (2, 4, 6 and 8 once days) and time in six levels (T1, T2, T3, T4, T5 and T6). In the during irrigation, vegetative traits such as scion height, leaf number, diameter of rootstock and scion, leaf water content and chlorophyll value were measured. Also, at the end of the experimental period, amount of nitrogen, phosphorus and potassium in soils mixtures were determined. The results showed that time of sampling, type of rootstock and duration of irrigation can affect on growth characteristics of studied rootstock and scion. Height of scion, leaf number, diameter of rootstock and scion were increased so that the increase for all traits to time T3 was significant, but from time T3 to T6 was not. The difference among different rootstocks in the absorption of nutritional elements in short time (two days) was more. Poncirus rootstock in uptake of nutritional elements in drought stress was more efficient than other rootstocks and with increase in intervals of irrigation, amount of nitrogen, phosphorus and potassium in soil mixture of Poncirus rootstock, was less. Overall, studied rootstocks in this research which are common citrus rootstocks in north of Iran, in drought stress conditions, did not show superiority over others in growth characteristics.
