جستجوی مقالات مرتبط با کلیدواژه « خیار » در نشریات گروه « زراعت »

Magnesium is an essential element for plant growth. Additionally, magnesium plays an important role in carbohydrate partitioning and dry matter production between the root and shoot. One of the main challenges facing vegetable producers in greenhouses in southern Iran is magnesium deficiency, especially in the middle of the growing season, due to various reasons such as poor water quality and excessive use and irrational consumption of potassium fertilizers in the reproductive phase. Therefore, finding practical solutions that help reduce the use of chemical fertilizers, production costs, environmental risks, increase efficiency, performance, and improve food security and sustainable agriculture is essential. The present study aims to propose a practical solution for improving the growth and quality of greenhouse cucumbers under conditions of reduced magnesium in the nutrient solution, while reducing fertilizer consumption, by using magnesium amino chelates and native seaweed extracts from the Persian Gulf. This experiment was conducted in the autumn and winter of 2022-2023 in the educational-research greenhouse in Shahid Chamran University of Ahvaz, in a split-plot design as a basic block with complete randomization and three replicates. The experimental treatments included foliar application of different concentrations of magnesium aminochelate (0, 2.5, and 5 ml/L) and seaweed extract of Sargassum angustifolium (0, 1.5, and 3 g/L). The foliar application of magnesium aminochelate and seaweed extract started two weeks after transplanting and continued once a week until one week before harvest (a total of 8 weeks out of 11 weeks). During the growing season and after the treatment effects, growth and quantitative factors such as root, stem, and leaf fresh and dry weight, leaf number and area, fruit fresh weight, fruit length and diameter, and qualitative factors such as TSS, pH, and EC of fruit juice, titratable acidity, fruit firmness, and fruit dry matter percentage were measured in cucumber plants. The results of the interaction between different concentrations of magnesium aminochelate and seaweed extract showed that with increasing magnesium concentration up to 5 ml/L and seaweed extract up to 3 g/L, there was a significant increase in root, stem, and leaf fresh and dry weight, leaf number and area, and fruit fresh weight. The Mg3×S3 treatment (5 ml/L of magnesium aminochelate and 3 g per liter of seaweed extract) and the control treatment (Mg1×S1) (zero ml/L of magnesium aminochlate and zero g/L of algal extract) had the highest and lowest values of growth indices, respectively. Increasing the levels of seaweed extract up to the 3 g/L and concentration of magnesium aminochlate up to the level of 5 ml/L led to a twofold increase in fruit fresh weight. The highest TSS of fruit juice was observed in the Mg3×S3 treatment (4.73%) and the lowest in the control treatment (Mg1×S1) (2.13%). The results of this study showed that in the reduced magnesium solution, simultaneous increase in seaweed extract and magnesium aminochelate led to an increase in cucumber fruit dry matter percentage. The lowest fruit dry matter percentage was observed in the Mg1×S1 treatment (2.27%), while the highest was observed in the Mg3×S3 treatment (4.78%). The findings of this experiment showed that the use of magnesium aminochelate probably increases chlorophyll production and seaweed extract through biomass improvement and growth stimulation ameliorates the growth, yield, and quality characteristics of cucumber fruit. Based on the results of this study, the use of 5 ml/L of magnesium aminochelate and 3 g/L of seaweed extract is recommended to improve the growth, yield, and quality indices of greenhouse cucumber under magnesium deficiency conditions.

Selenium is a beneficial element with antioxidant and antivirus function and it can increase plant growthand tolerance to environmental stress.Inthis study, the effects of selenium in stress conditions caused by heavy metals cadmium, nickel and lead in cucumber (Cucumis sativus L. cv Super Dominus) was investigated.The research was conducted using a completely randomized design with factorial arrangement in three replications for two germination tests .The first experiment was carried out to determine the optimal effectiveness of selenium and heavy metal toxicity threshold levels, Which contains levels of selenium (0, 4, 6, 8, 10 mgL-1) from sodium selenate, cadmium (0, 10, 15, 20, 25 µM) from cadmium chloride, nickel (0, 50, 100, 150, 200 µM) from nickel chloride and lead (0, 20, 40, 60, 100 µM) from lead chloride sources. The second experiment were consisted of two levels of selenium (0, 8 mgL-1) and toxicity threshold levels of heavy metals, including cadmium (0, 25 µM), nickel (0, 200 µM) and lead (0, 100 µM) treatments.The results showed that the germination index was significantly reduced as presence of toxic concentrations of heavy metals in the medium of cucumber seed germination. However, the application of selenium was improves the rate and percentage of germination, increase the length of shoot and root and seedling wet and dry weight in stress condition.Selenium was significantly increased cell membrane stability and decrease malondialdehyde under stress condition.Selenium improved antioxidant activity and increase activity of catalase, ascorbate peroxidase and guaiacol peroxidase enzyms in heavy metal toxicity condition .In general, the results of this study showed that the optimum concentration of selenium was reduces symptoms of toxicity due to the presence of heavy metals incucumber seedgermination mediumas  improving germination, growth and antioxidant activity.

Chromosomes number of haploid plants at the sporophyte (2n) stage is equal to the chromosomes number of the gametophyte (n) stage. The objective of haploid plant production is to obtain doubled haploid (DH) lines universally suited to breeding programs. Crop productivity can be greatly improved by using F1 hybrids, which are made by crossing pure lines with some important traits. These pure lines are very valuable in breeding programs and genetic researches. Production of pure lines in a conventional breeding program via self-fertilization takes a long time and requires high costs, but still may not be 100% homozygous. Alternative biotechnological approaches are by far more efficient and sustainable than traditional methods. The most common and best-known method of obtaining haploid cucurbit plants is via pollination with irradiated pollen, which induces parthenogenetic development of haploid embryos in plants. According to the previous reports, there has not been consensus for superiority of gamma ray doses between 300 and 500 Gy; however these two doses have not been simultaneously compared in any research study published so far. The aim of this study was to investigate the possibility of haploid embryos induction in different cucumber cultivars through pollination with gamma-irradiated pollen and determine the optimal dose of irradiation for cucumber haploid plants production. This research study was performed in a factorial experiment with two factors (gamma irradiation dose and plant genotype) based on a completely randomized design (CRD) with 6 replications. In this study the effects of irradiation doses and maternal genotypes on fruit set, seed production, parthenogenetic embryo induction were investigated after pollination by irradiated pollen and production of haploid plants in cucumber. Seven cucumber (Cucumis sativus L.) genotypes including, Extreme F1, Negin F1, Karim F1, Super Dominus F1, Beith Alpha OP, Basmenj and Dasgerdi were pollinated with gamma-rays irradiated pollen grains at doses including 300 and 500 Gy. The pollen viability and pollen tube behavior after irradiation were evaluated. The seeds extracted from the fruits were rescued by in vitro embryo culture, and the ploidy level of the plantlets obtained was determined by flow cytometry. The impact of different doses of gamma irradiation, genotype, and interaction of dose and genotype on total number of seeds produced were significant. The highest number of parthenogenic embryo were observed in genotype Extreme irradiated with dose of 300 Gy (2.25) and genotype Karim irradiated with dose of 500 Gy (1.75). No embryo and plant was obtained in genotypes Negin, Extreme and Beith Alpha irradiated with the dose of 500 Gy. The difference of various doses of irradiation on production of haploid plants was not significant, but genotype and especially interaction effect of dose and genotype were significant on production of haploid plants. Pollination of genotype Extreme by 300 Gy – irradiated pollen grains gave rise to the highest number of haploids (1.25Hs/fruit) produced in this experiment. In this research study similar to previous studies, it was confirmed that production of haploid plants using irradiated pollen grains is an efficient method for producing haploid inbred lines in cucumber. According to our results, different genotypes exhibited different responses to various doses applied and parthenogenic embryogenesis can be induced when optimal dose of irradiation was applied in each genotype.

This experiment was conducted to investigate heritability, combining ability and genetic control of important traits of greenhouse cucumber inbred lines in 2015-2016. The genetic materials used in this experiment were 52 hybrids from 10 male and 27 female cucumber inberd lines which were examined in two separate experiments. These experiments were carried out as North Carolina Design I using randomized complete block design with three replications. The results showed that male parents 1, 2 and 13 had the highest values of vegetative traits in both experiments. Estimation of genetic parameters for vegetative traits also indicated low levels of additive variance and narrow-sense heritability. The highest total number of fruits in the first experiment was observed in male parent number 7. Regarding fruit yield related traits, male lines number 7 and 15 in the first experiment had higher fruit yield. The results of second experiment showed that the longer fruit production duration and higher number of fruit per node belonged to male parents 10 and 3, respectively. There was no significant differences for other fruit related traits. Estimation of genetic parameters showed that in many of traits associated with fruit such as fruit diameter, fruit firmness, fruit number and yield, the additive variance and narrow-sense heritability were high, therefore, it is possible to select successfully for these traits. In general, male inbred lines number 7, 13, 15, and 24 contributed to increasing of fruit-related traits and fruit yield in progenies.

In this research, the effect of ovary co-culture on androgenesis efficiency in anther cultures of four cultivars of cucumber was studied. A factorial experiment based on Completely Randomized Design with three replications was used in this study. Cultivars of cucumber (Beta Alfa, Esfahani, Basmanj and Korki), type of culture medium (solid and liquid) and number of cucumber ovaries (0, 10, and 20) were considered as the experimental factors. Different cultivars of cucumber, two type of culture medium, different numbers of ovaries in culture medium, two-way interaction effects and triple interaction effect of cultivar × culture medium × ovary number showed significant differences (p

The effect of spermidine on seed germination of three different cucumber cultivars under cold stress was studied as a 4×2 factorial experiment by using a completely randomized design with 4 replications. First factor was 4 concentrations of spermidine consisted of 0 (control)، 0. 1، 0. 5 and 1 mM and the second one was three cucumber cultivars consisted of ‘Emperator’، ‘Amiran’ and ‘Rashid’. For this purpose، 50 seeds of each cultivars were placed on filter papers inside steriled petry dishes and spermidine solutions were added to them according to each treatment. All petry dishes were placed in a 13°C temperature of the incubator until end of the experiment and germinated seeds were counted daily. The measured traits were percentage of germination، plumule length، radicle length، dry and fresh weight of the plumule and radicle. The results showed that treating seeds of ‘Rashid’ cultivar with 0. 1 mM spermidine increased percentage of germination، plumule and radicle length، fresh and dry weights of radical compared with control. Treating ‘Rashid’ seeds with high concentration (1 mM) of spermidine showed inhibitory effects on all measured characteristics، but in ‘Amiran’ cultivar only decreased percentage of germination، plumule and radicle length، fresh and dry weight of ridicle.

Chitosan، is non-toxic، biodegradable and biocompatible material، which can be used as edible coatings to maintain quality and enhance postharvest life of fruits and vegetables. In this study، the effect of chitosan at 0، 0. 5، 1 and 2% concentrations on storage life of cucumber cv. «Zomorod» was investigated. After treatment and keeping in an incubator at 12 °C and 90% relative humidity، the fruits were assessed in 5-days intervals to determine parameters such as firmness، weight loss، vitamin C، titratable acidity، soluble solids and chlorophyll content. Experiment was performed as a split-plot design in time in a completely randomized design with three replications. The results of the experiment showed that chitosan coating، had a significant effect on all traits except titrable acidity. The lowest weight loss and the highest firmness were recorded with 1% chitosan treatment which significantly differed from the control. It is appeared that chitosan coatings could be used to increase the storage life of cucumber fruit and to maintain its quality for a longer period.

One of the important factors for successful agriculture is suitable planting date. For off-season cultures، we need to protect plants from adverse environmental conditions. This experiment was conducted to determine the most suitable planting date for cucumber under semi tunnel and polyethylene mulch conditions at Kaboutar-abad research station of Isfahan during two years. The experimental design was a completely randomized block design in a split plot arrangement with four replications. Four planting dates (February 4th، February 19th، March 6th and March 21) formed the main plots and soil covers (semi tunnel with black and transparent polyethylene mulches and semi tunnel without mulch) formed the subplots. The results indicated that planting dates had no significant effect on yield but was effective in early maturing yield. Planting date of February 19th produced the highest yield (6. 4 T/ha). Soil cover had a significant effect on the traits. The highest yield، plant vegetative growth and early maturing fruits were obtained in semi tunnel with transparent mulch. Applying semi tunnel with transparent and black mulches during February 19th till March 6th had the best efficiency for producing out of season cucumber in Isfahan climatic conditions. Polyethylene mulches reduced the salt accumulation on furrows.

Ten greenhouse cucumber cultivars (Al-Biruni F1، Borhan، Donia، Ivor، Cluster5، Jiroft F1، Karim F1، Katrina، Negin، Terminator and Tunca) were screened for resistance against the root-knot nematode، Meloidogyne javanica under controlled environmental conditions in greenhouse. Seedlings of cucumber cultivars were inoculated with five J2s/g soil. Seven weeks after inoculation، the reaction of the cultivars was evaluated. According to the results، none of the tested cultivars were resistant to the nematode. Based on the stem-related parameters، cultivars Karim F1، Al-Biruni F1، Donia and Borhan، and regarding root-related parameters، cultivars Al-Biruni F1، Donia، Katrina and Ivor showed good performance against the nematode. Based on the nematode reproduction factors، cultivars Karim F1، Jiroft F1 and Ivor had the lowest number of nematode. Considering the resistance index، cultivar Karim F1 was evaluated as moderately susceptible، cultivars Jiroft F1 and Ivor as susceptible and the remaining cultivars were very susceptible. In cluster analysis of growth-related parameters، two separate groups were recognized. Cultivars Karim F1، Al-Biruni F1، Tunca and Borhan were classified in one group and five other in another group. Based on the results of cluster analysis of nematode-related parameters، maximum similarity was observed in a group composed of the cultivars Terminator، Ivor، Donia، Karim F1 and Jiroft F1. Two cultivars Biruni F1 and Negin were completely different from other cultivars.

This study was conducted to evaluate genetic diversity in eight native populations of Iranian cucumber including Birjand, Roudbar, Gorgan, Kashan, Yazd, Taft, Sanandaj, and Isfahan in comparison with Super Daminus hybrid as control in a randomized complete block design with three replications for two years (2007 and 2008) in two regions (Varamin and Isfahan). Studied traits were days to flowering, number of fertile flowers, the ratio of female/ male flowers, number of branches, days to first harvest, average number of fruits per plant, weight of fruits per plant, average fruits length per population, the ratio of three first harvest / total yield and average yield per plant. The results indicated the existence of high genetic differences between local populations and Super Daminus hybrid. Based on cluster analysis, populations were classified in three groups. According to clusters segregation in the highest difference level, Super Daminus had the highest difference with other populations showing that this hybrid has a genetic different from other populations. After control cultivar, Yazd and Taft populations had the most differences with other populations, respectively. Maximum similarity was observed between Isfahan and Kashan populations and amang Gorgan, Roudbar and Sanandaj populations as well. Furthermore, Isfahan and Kashan populations were similar to Birjand population and three of them were somewhat similar to Gorgan, Roudbar and Sanandaj populations.

Root and foot rot caused by Phytophthora drechsleri is an important disease of cucumber in field and greenhouse. One of the best control methods of the disease is use of resistant cucumber cultivars or grafting cucumber plants on resistant cucurbit rootstocks. In the present study, resistance of fourteen cucurbit and cucumber cultivars at different growth stages was evaluated in greenhouse conditions using a completely randomized design in two replications. Susceptibility of cultivars was assessed by percentage of dead plants. Cultivars showed different responses to the disease and were classified into five very susceptible, susceptible, moderately susceptible, moderately resistant and resistant groups. Cucurbit cultivars Kadu Halvaee and Kadu Khoreshti Toopor va Kootah, and cucumber cultivars Boskoo and Dastgerdi with 100, 100, 99.30 and 92.34 percentage of dead plants, respectively were very susceptible and cucurbit hybrids RS841, RS107 and RS152 and Kadu Tanbal cucurbit cultivar with 23.60, 20.12, 15.03 and 10.18 percentage of dead plants, respectively were resistant.

Based on the previous investigation results, fifteen Iranian cucumber landraces, eight as male and seven as female, were crossed with each with each other in an 8×7 factorial design, North Carolina Design II (NCD II). Eight quantitative and qualitative components including flesh texture firmness, skin texture firmness, aroma, taste, crunchy, fruit dry matter content, fruit flesh size and placental diameter/fruit diameter ratio were evaluated in F1 hybrids. In factorial design, male and female were not significant for most of the traits. indicating that the additive genetic variance did not contribute on controlling the traits. Male × female interaction was significant for all of the traits. Therefore, F1 hydrids can be used for getting hetrosis in all of the characters. High broad-sense heritability of hybrids showed high genetic variations of the traits in the germplams. The genetic correlations showed that decreasing placental diameter/fruit diameter ratio increased fruit crunchy and more crunchy fruits had the better taste. The 97 × 39 hybrid was the best hybrid via aroma, taste traits related to mid-parents and superior parent. The best selection criteria for breeding of the flavor was aroma, taste and crunchy selection. Ratio of gain from selection index related to that from aroma, taste and crunchy selection, separately were about 1.009, 1.004 and 1.001 percent more, respectively.

Two greenhouse-cucumber cultivars, Festival and Negeen that are resistant and susceptible to Fusarium oxysporum f.sp. radicis-cucumerinum, respectively, were used for histopathological studies. On days 3, 6, 10 and 18 after artificially inoculation with fungal plugs that were placed as close as possible to the crown and root of seedlings, samples were prepared from crown and roots of infected plants. After sectioning, fixation and staining, samples were investigated microscopically. Cortex tissue discoloration, tissue disintegration, development of mycelium in cortex of root and increasing in production of pectic compounds occurred in infected tissues. Pathogen growth, disintegration and discoloration in resistant cultivar restricted to the superficial layers of cortex, while in susceptible cultivar these phenomena developed in whole root system and reached to the vascular stele. The pectic compounds production in infected tissues started a few days after inoculation and the level of these compounds in resistant cultivar was higher than susceptible cultivar at day 18 after inoculation. According to these results, cell wall rigidity and level of cell wall pectic compounds can be considered as two important components of resistance in breeding programs for development of resistant cultivars to the disease.

This experimental was conducted to investigate the efficiency of polyethylene mulches and suitable sowing method on row, for cucumber in field in Isfahan during 2000 and 2001. Cultivar of cucumber was Super dominos hybrid. Statistical design was split plot on randomized complete block with four replications. Soil cover in three levels (black mulch, transparent mulch and without mulch) were considered as the main plot and sowing method in two levels (single and double rows) as sub plot. Field management and data collection from different treatments were done during growth period. Results showed that transparent polyethylene mulch had a positive effect on early germination of seeds and precocity production. Yield in transparent, black and non mulch treatments were 57.5, 40.2 and 33.6 (tha-1), respectively. Maximum plant vegetative growth and minimum weed were obtained from black polyethylene mulch treatment. Polyethylene mulches had a favorite effect on soil moisture maintenance in bed. Maximum yield was obtained in double row sowing method, but single row sowing increased the marketability of fruits, length and weight of plants.

Cucurbit wilt caused by Phytophthora drechsleri is one of the most important diseases in Varamin and Garmsar areas. Reduction of yield of cucurbit by this disease has been reported about 25%. Soil salinity which can cause the important damage to the plant metabolism and nutrition, is common in these regions. Cucumber is susceptible to salinity stress. Therefore salinity stress may increase the susceptibility of cucumber to Phytophthora drechsleri. Different levels of salinity (control, 0, 10, 25 and 50 mM NaCl) on three current cultivars (Tezier, Super 2000 and U. S. A.) of cucumber were investigated at the presence of P. drechsleri in greenhouse conditions. A factorial analysis for completely randomized design with 3 replications, was used for these experiments. Significant differences were observed among the different levels of salinity. Increasing stress due to salinity increased the susceptibility to the disease. Cucumber cultivars had different responses to salinity. The effects of different levels of salinity (0, 10, 25, 50 and 75 mM NaCl/l) were also investigated on growth of P. drechsleri on CMA culture at a completely randomized design with 3 replications. Variance analysis of growth area of fungus on CMA culture showed significant differences among different levels of salinity. Growth area of fungus was 6359 mm2 for control and 4725 and 4797 mm2 for 50 and 75mM NaCl, respectively.