جستجوی مقالات مرتبط با کلیدواژه "seedling establishment" در نشریات گروه "زراعت"

Seed priming is the simplest and the best method to increase seed germination speed.

To address this, in a study aimed at the effect of priming of different barley (Hordeum vulgare L.) cultivars on various germination characteristics, in the form of a factorial experiment was conducted using a completely randomized design with four replications in the research greenhouse of the Agricultural and Natural Resources Research Center of Hamadan province in 2022. Treatments including priming of seeds with fertilizers 1. Biozar, 2. Seafull amino zinc, 3. Sabzine, 4. Royesh, 5. Ecobooster, and 6. control (no fertilizer application), and different barley cultivars including Jolgeh, Bahman, Azaran, Abidar, Ghaflan, and Sahand.

The results indicated a significant effect of seed priming on the evaluated characteristics compared to the control treatment. The highest enzyme activities of catalase (0.117 Unit/ml) and peroxidase (85.08 Unit/ml) were obtained in seedlings obtained from seeds priming with Seafull amino zinc, which were 72 and 33% more than control treatments, respectively. The highest seedling vigor index was related to the seeds priming with seafull amino zinc fertilizer (26.55), which was significantly higher than the control treatment (22.84) and other treatments. Also, the germination percentage of seeds priming with seafull amino zinc fertilizer was significantly higher (3.5%) than the control.

Considering that seed priming is a cost-effective and easy method and at the same time it is simple and does not require complex technical knowledge, it can be easily implemented by farmers. Therefore, this method is recommended to improve germination, seedling growth, and the quality and strength of barley seeds.

This project was carried out to study and classify the lentil (Lens culinaris Medik) genotypes during germination and seedling establishment, in Greenhouse and in two stages. First stage was carried out with 43 genotypes and Mardom cultivar of lentil in 4 levels of salinity and 3 replications in factorial experiment in as a completely randomized design in a combination of non-saline and saline soil in the 1, 2-1, 1-1 and 1-2 weight ratios (respectively non-saline soil and saline soil). Second stage was carried out with 3 genotypes and Mardom cultivar of lentil in 4 levels of salinity of NaCl (0, 60, 120, 180 mM) and 3 replications in a factorial experiment based on a completely randomized design. In this project, some morphological characteristics as well as the content of chlorophyll a and b, carotenoids and proline were evaluated. Analysis of the results showed that as the salinity increased, morphological traits in most genotypes were significantly damaged. For clustering genotypes in the first experiment, cluster analysis and principal component analysis was carried out and genotypes were classified in four different groups. 4 genotypes for second experiment were selected according to the results of cluster analysis. Results showed that there was high diversity in lentil genotypes in response to salt stress, and we can use this diversity in cultivars breeding programs.

About 6.8 million hectares of agricultural lands in the country have different degrees of salinity, of which 4.3 million hectares have only salinity limits. The response of plants to salt stress is complex and depends on various factors such as concentration and type of solutes, plant species, plant growth stage and environmental factors. The use of salinity tolerant cultivars is currently one of the most effective ways to exploit and increase yield in saline and low saline soils. Chenopodium quinoa Willd. is a native plant of the Andean region of South America that was cultivated there from 5,000 to 7,000 years ago. The Food and Agriculture Organization (FAO 2002) designated Quinoa as one of the most important crops for food security of the world's population in the last century. Most Quinoa cultivars are capable of growing in salinity at concentrations of 40 (dSm-1) and even higher. This salinity is too high for most crops. Increasing the concentration of NaCl in the nutrient solution, followed by increasing the osmotic potential, adsorption of Na+ and Cl- ions during seed germination causes cell damage and ultimately inhibits or reduces germination. Therefore, the purpose of this study was to evaluate the effect of salinity caused by the use of poor quality water on yield and yield components of Quinoa as well as germination components of different Quinoa cultivars.

This study was carried out in cultivation in controlled environment (germination apparatus) at the Faculty of Agriculture, Shahid Chamran University, Ahvaz, Iran, in order to evaluate the reaction of cultivars and genotypes to salt stress conditions. In the experiment conducted under controlled conditions, the experimental treatments included salinity (NaCl) at six levels (0, 10, 20, 30, 40 and 50 dSm-1) and three genotypes and genotypes of Quinoa (Giz, Titicaca, Q26) was performed as factorial experiment in a completely randomized design with three replications. To find plant respanses and chose the best one using seed number and germination rate, percentage and germination rate, seed Vigor index, mean germination time, time to 10% germination, time to 50% germination and time to 90% germination were calculated according to the equations.

The results of analysis of variance showed that salinity stress had a significant effect on germination percentage and rate, and other measured germination indices (p < 0.01). Interaction of cultivar and salinity stress on root length, stem length, root dry weight and shoot dry weight, seed vigor index, germination uniformity, D10, D50 at 1% and germination percentage at 5% were significant. With increasing salinity levels from the control treatment to the highest salinity level (50 dSm-1), the decreasing trend of root and shoot length as well as root and shoot dry weight was observed. Titicaca showed the highest germination percentage and the highest seed vigor index in control treatment. In the salinity-free treatment, Titicaca showed the best and worst yield in Q26 at 50 (dSm-1) for 10% germination. Among other cultivars, Titicaca showed the highest root and shoot length and the lowest root and shoot length at 50 (dSm-1) under non-salinity stress conditions. Titicaca cultivar had the highest and Giz cultivar had the lowest germination and root dry weight. Titicaca cultivar in control treatment showed the highest root and shoot length with an average of 5.53 and 5.57 cm, respectively, while in salinity treatment of 50 dS/m-1 with an average of 0.4 and 0.3 cm minimum root and shoot length. Also, the best uniformity in germination with 20.2 hours was observed in Titicaca cultivar in control treatment.

At low salinity levels, acceptable yield was observed but in sever salinity condition most of the crops could not grow during the phenological stages. According to the results of this study and the study of quinoa behavior and high tolerance of the plant in the germination stage in the face of salinity stress, to improve salinity resistance in crops through breeding programs, and further study of salinity defense mechanisms in susceptible cultivars It is recommended. It seems that despite the significant effectiveness of all three cultivars and significant reduction in germination indices at high salinity levels Titicaca cultivar had a higher tolerance threshold than the other two cultivars, indicating the diversity of cultivars in response to physiological processes to salinity stress. It is also possible to use this cultivar with further research into breeding and breeding programs of other sensitive quinoa cultivars.

The effect of environmental factors on the developmental stages of a plant causes the planting date to vary from one region to another. Temperature is a very important factor in the maximum percentage germination and germination rate. Priming improves germination rate, brings about the uniformity of germination and reduces seed susceptibility to environmental factors. The purposes of this experiment were to study the effects of priming treatments at different temperatures on the germination characteristics of Hibiscus sabdariffa under laboratory conditions,  to investigate priming treatments on different planting dates and to compare early planting dates on the farms.

The experimental study was carried out as a factorial experiment in a completely randomized design with four replications in the Laboratory of Seed Technology of Kashmar University Jihad. The first factor is five primings (Concentrations of ZnSO4 (10 mM), Humic acid (2.5 cc) and the combination of Humic acid and Zinc sulfate, Biological materials (Pota Barvar 2), no treatment (control) and the second factor is five levels of temperature: 10, 12, 14, 16 and 18 °C. Field studies were carried out in Agricultural and Natural Resources Research Center of Kashmar in three separate experiments in 2018. The research was carried out in a completely randomized block design with three replications on three planting dates (March 25th, April 15th, and May 4th, 2018). In each experiment, priming treatments were applied similarly to field experiments.

The results of the current experimental study showed that temperature, priming and temperature interaction with priming had a significant effect on all the traits studied. The highest percentage and rate of germination were observed at 18 °C and priming with Pota Barvar 2. The results also showed that planting date had a significant effect on all the traits studied in the field experiment. Priming showed a significant difference only in stem fresh weight. The interaction effect of priming and planting date was not significant for the traits studied. The highest germination percentage was obtained on April 15’s planting date. By planting later than March 25 to 15 April, a decrease of 74% was observed in the rate of germination. Among priming treatments, the combination of Zinc Sulfate and Humic acid showed a significant superiority, compared with other treatments.

The findigns suggest that due to the high sensitivity of seed germination of sour tea at low temperatures, the planting date in each area should be carefully chosen so that it does not coincide with temperatures below 18 °C.

IntroductionDrought and salinity are major environmental factors that influence crop productivity worldwide .Plants are normally subjected to a combination of various types of abiotic stresses in nature, such as the combined effects of drought and salinity .Studies have revealed that the physiological and biochemical responses of plants to the interaction of drought and salinity are unique and cannot be directly extrapolated from the responses to the two stresses individually.Storage of orthodox seeds for prolonged period induces their deterioration leading ultimately to loss of their viability. The rate of seed deterioration varies among plant species and seed lots, but high moisture content and high temperature accelerate this process. During long-term storage, all seeds undergo aging processes leading to deterioration in seed quality, especially in the humid tropical regions. However, the rate of seed deterioration can vary among various plant species. When aged seeds are sown, they show decreased viability, lower germinability performance, and produce weak seedlings which could not manage to survive in their habitat. Seed priming (osmoconditioning) has been successfully demonstrated to improve seed germination and seedling establishment for many field crops.The beneficial effects of priming have also been demonstrated on germination and seed emergence, as well as seedling establishment of many crops, particularly under drought and salt stress.Use of chemical compounds as priming agents has been found to improve plant tolerancesignificantly in various crop and non-crop species against a range of different individually applied abiotic stresses.Melatonin, due to its pleiotropic effects can play important roles in improving plant tolerance to adverse conditions.Safflower (Carthamus tinctorius L.) is one of the prospective oilseed crops because it yields about 32–40 % seed oil. However, due to its considerable salt resistance than commonly grown oilseed crops, it is cultivated in arid and semi-arid regions where soil salinity is one of the major threats to agriculture.Drought is very unpredictable among abiotic stresses in terms to occurrence, severity, timing. and duration and safflower can be a promising alternate crop in dryland agro-ecosystems due to its growth potential under water stress without a substantial reduction of oil and seed yields. Safflower cultivation constitutes a more profitable crop for the farmers in some countries, compared to other conventional crops such as barley, lentil, and chickpea.The fact that safflower can overcome environmental stresses such as extreme temperatures, drought, and salinity has facilitated its expansion in areas around the world, where soil and climatic restrictions have impeded the cultivation of conventional food and cash crops.In particular, safflower has demonstrated drought resistance with a slight decrease in crop yield and significant stability in water use efficiency Materials and methods In order to study the effect of seed priming of naturally aged seed by melatonin on seedling emergence and growth characteristic of safflower, three experiments were conducted at seed science technology laboratory, greenhouse and research farm of Aburaihan Campus, the University of Tehran in 2017. The experimental design for all experiment was factorial in completely randomized design (laboratory) and randomized complete block design (research farm and greenhouse) with 4 replicates. The main treatments that common between experiments consist of seed quality (1-naturally aged seed 2- new seed) and seed priming (1-without priming 2- hydropriming 3- Melatonin 0.1 mM 4- Melatonin 0.5 mM). Soil water was determined based on soil moisture release curve, which indicates the relationship between soil water potential andsoil moisture content. Prior to the pot experiments, three samples of wet soil (wet soil = drysoil ? soil moisture content) were dried and soil moisture content at the beginning of experiment was determined.Then pots were equally filled with wet soil. Two pots were considered as references and were weighted each day: one for drought stress and one for other abiotic stresses. The soil moisture content could be obtainable after weighing and it was possible to calculate soil water potential from soil moisture release curve. Results and discussionThe results of this research indicated that the highest percentage of seedling emergence of naturally aged seed obtained by hydropriming and melatonin priming at 0.1 mM by %54.50 and %57.50 that increased the seedling emergence up to %39.74 and %47 respectively, in comparison to control in the farm condition. Also, the results showed that highest percentage of seedling emergence under drought condition belong to melatonin priming at 0.1 mM concentration that increased the seedling emergence up to %154 in comparison to control in the greenhouse condition. The results of this experiment indicated melatonin priming at 0.1 mM concentration led to the highest rate and percentage of seedling emergence under salinity and combination of salinity and drought condition while melatonin priming at 0.5 mM concentration has decreased the rate of seedling emergence.ConclusionsIn general, using of seed priming as a cost-effective method also hydropriming and melatonin priming could enhance the seed quality for growth under salinity and drought conditions.

Accurate prediction of seedling emergence in the field is crucial for the performance of growth models. In order to determine thresholds of seedling emergence response to temperature, two replicated field experiments were carried out at Ramin Agriculture and Natural Resource University of Khuzestan during 2015-2016 and 2016-2017. In these experiments, seedling emergence of two spring canola cultivars (Hyola 401 and Sarigol) was evaluated in a randomized complete block design with four replications in fifteen planting dates (as environment). Thermal-time model was developed based on the Weibull probability distribution function, and thermal thresholds for seedling emergence response of two spring canola cultivars in field conditions was modeled based on this function. Based on model outputs, the base temperature for seedling emergence (Tb) was estimated to be 5.83 °C in the hybrid Hyola 401 and 4.16 °C in the cultivar Sarigol. The thermal-time required to initiate seedling emergence at sub-optimal temperature range (θT(0)) and the thermal-time needed to complete seedling emergence at supra-optimal temperature regimes without significant differences between two cultivars was estimated to be 55.5 and 5.65 °C d, respectively. Maximum temperature for the 50% probability of the thermoinhibition of seedling emergence (Tm(50)) in hybrid Hyola 401 and cultivar Sarigol was estimated to be 33.02 and 33.30 °C, respectively. The optimum temperature for 50% seedling emergence in the field (To(50)) for hybrid Hyola 401 and cultivar Sarigol was determined to be 30.99 and 31.22 °C, respectively.

Lentil (Lens culinaris Medic.) is one of the most important pulse crops in the world. High protein content in lentil seed (about 20-28%) makes it as a good food source for developing countries and low-income people. In the west of Iran, such as Kermanshah Province, lentil is an important pulse crop of rain-fed systems, traditionally grown in rotation with wheat and barley. Many seed tests have been proposed to evaluation of seed vigor, such as standard germination test, cold test, electrical conductivity test, hiltner test, tetrazolium test, controlled deterioration test, accelerated aging test, osmotic stress test, etc. To osmotic stress test, the seeds germinate at a specific osmotic potential. Osmotic potential is prepared by various chemicals such as sodium chloride, glycerol, sucrose, polyethylene glycol (PEG) or mannitol. Some of these chemicals enter the seed during germination. But PEG has the ability to reduce the osmotic potential of the solution without entering the seed. Therefore, it is often used for osmotic stress test to prepare the solution. Regarding the fact that smotic stress test to predict seedling emergence in the field for common lentil cultivars has not been carried out under dry land conditions of Iran. Therefore, in the present study, the relationship between osmotic stress test and emergence and establishment of lentil seedlings in the field was investigated.

This research was carried out in two experiments in the laboratory and the field at Razi University during 2015. In laboratory, osmotic stress test was done as a factorial based on CRD with three replications. Treatments included eight lentil seed lots and four osmotic stress levels (0, -3, -6 and -9 bar). Eight lentil seed lots belonging to the four cultivars Kimia, Bilesavar, Qazvin and Local which were different in seed age were considered for testing. PEG-6000 solution was used to prepare osmotic potential. The seeds germinated at 20 ± 1 °C. During germination, various traits related to seed vigor were investigated. In the field, eight above mentioned lentil seed lots were planted as rainfed in RCBD with three replications. Each plot consisted of four rows at intervals of 25 cm, seed spacing 2.5 cm and sowing depth 4-5 cm. The seeding date was March 2014. The first rainfall after planting was considered as seeding date. By observing the first emergence of seedlings in the field, the seedlings were counted daily in each plot, and counting continued until the number of seedlings was fixed. In the field, indices related to the seedling vigor were studied.

Analysis of variance for osmotic stress test showed that the effects of seed lot, osmotic potential and their interaction were significant on most traits. Mean comparisons showed that with decreasing of osmotic potential from 0 to -6 bar, the final germination percentage, germination rate and other characteristics related to seed vigor decreased. Analysis of variance and mean comparisons in field experiment showed that the lentil seed lots were different in terms of the traits final emergence percentage, mean daily emergence, mean time to emergence and seedling emergence rate. In orthogonal comparisons of laboratory and field tests, new seed lots had higher germination and emergence characteristics than stored seed lots. Correlation analysis showed that in the osmotic potential 0 bar traits of the use of seed storage, root and stem dry weight; at -3 bar traits of the mean daily germination and the use of seed storage; at -6 bar traits of the mean daily germination, germination rate, normal seedling percentage and the use of seed storage had positive and significant correlations with the seedling emergence percentage in the field. In the osmotic potential 0 bar, traits of the germination rate, seed vigor index, stem length, root and stem dry weight; at -3 bar traits of the final germination percentage, mean daily germination, germination rate and normal seedling percentage; at -6 bar traits of the final germination percentage, mean daily germination, germination rate, normal seedling percentage and seedling vigor index showed higher correlations with the seedling emergence rate in the field.

The highest positive and significant correlations were observed between seedling emergence percentage in the field with the osmotic stress test associated with mean daily germination and normal seedling percentage in -6 bar. Also, the highest positive and significant correlations were observed between seedling emergence rate in the field with the osmotic stress test associated with mean daily germination, germination rate and normal seedling percentage in -6 bar. Therefore, it seems that osmotic stress test at -6 bar can predict the emergence of lentil seedlings in the field under rainfed conditions.

In this research, the effect of concentration and time of seed priming with salicylic acid on germination and early growth and it’s application methods under salinity stress conditions on phenology characteristics of barley, variety Reyhan, was studied in two separate experiments. The effect of concentration (in five levels, control, 0.5, 0.75, 1.0 and 1.5 mM) and time (in three levels, 6, 12 and 24 h) of seed priming by salicylic acid (SA) in the first experiment and different application methods of SA (no application, priming and spraying at the stages of establishment, double ridges and anthesis) under different salinity conditions (no stress and salinity of 6 and 12 dS.m-1)in the second experiment was evaluated. Both experiments were conducted as completely randomized design with four replications at College of Agriculture, Shiraz University, Iran, in 2014. The results of the first experiment showed that SA-priming with 1.5 mM for 12 h had the highest positive effect on germination and early growth, which was selected for the second experiment. The results of the second experiment showed that salinity stress of 6 dS.m-1 reduced the planting to anthesis period as well as planting to physiological ripening and 12 dS.m-1salinity stress also reduced the planting to booting, planting to anthesis and planting to physiological ripeningperiods. Seed priming with SA prolonged the growth periods, whereas the delay in SA application decreased its positive effect. Foliar application at establishment increased planting to booting, planting to anthesis as well as planting to physiological ripening periods,however foliar application at anthesis had no significant effect on phenology of barley plants. In total, seed priming or foliar application at establishment at early growth stages ameliorated the acceleration of the developmental stages due to salinity stress and early application of SA was found to be more important with increasing salinity stress.

This study aimed to determine the role of seed priming on different methods of rice cultivation was performed. A factorial experiment in randomized complete block design with four replications was conducted at the experimental field of Rice Research Institute of Iran (RRII), Rasht, Iran, duringtwo years (2013 and 2014). The experimental factors were included two rice varieties (KhazarandHashemi) and ten cultivation methods (eight priming, combined with seed tape technology plus two treatments, linear direct seeding and transplanting). The measured characteristics were including characteristics of seeds and seedlings in the lab and other phenological and morphological characteristics. Also, the descriptions of the three planting methods were discussed (direct seeding with seed tap technology, linear direct seeding and transplanting). The combined analysis of variance showed that seed priming had significant effects on seed and seedling traits. Most of seedling establishment in the field was related to dry seed treatment. There was no significant seed priming effect on yield, while there was significant impacts of cultivar, the interaction between cultivar and priming on yield. Most grain yield was, Khazar cultivar of transplantation treat, and in Hashem cultivar was in seed priming treat with calcium chloride. results showed that the direct seeding using seed tap technology, declined by 11 percent during the growing season, 32% of the number of workers, the experiment was better than transplanting method. The overall result of this experiment showed that direct seeding with seed tap technology can be 12 percent reduced in rice production cost.

Success of seed germination and seedling establishment of perennial grasses, which are sensitive to environmental stresses, is of great importance in the renovation and amendment of pastures. To achieve this, seed priming technique was evaluated in improving germination rate and seedling vigor of five perennial cool season grasses including Bromus confinis, Elymus elongatum, Agropyron pectiniforme، Festuca ovina، Festuca arundinaceae using Polyethylene Glycol 8000 for 0, 0. 5, 1, 1. 5, 2, and 2. 5 MPa concentrations and 0, 2, 4, 6, and 8 days duration (D). The study was conducted as a factorial experiment based on CRD with four replications. ANOVA results showed that there were significant differences between all studied traits and their interactions for germination rate and seedling components (P<0. 01). Seed priming significantly increased germination rate comparing with the control (non primed), so that there were 127. 9, 77. 8, and 66. 5% increase in germination rate comparing with the control (2 days in 2 MPa) for B. confinis, A. pectiniforme and E. elongatum, respectively, and 96. 5% increase for F. arundinaceae (6 days in 1. 5 MPa) whereas the lowest increase in germination rate (15%) was observed for F. ovina (4 days in 2. 5 MPa). The regression analysis revealed that increasing PEG concentration decreased shoot and root dry weight for all species except F. arundinaceae and F. ovina. The greatest seedling growth reduction was detected for large seeded species B. confinis, and E. elongatum when treated for long duration (more than 2 days) and low concentrations of PEG. Overall, The results of this study suggested that seed priming with higher concentrations of PEG about 2 and 2. 5 MPa and 2 days seed storage duration plays an important role in the success of grasses seed priming technique and also it revealed that small seeded species might show a better response to priming in improving seed germination and seedling establishment than that of large seeded ones.

Effects of seed priming in Zn and P solutions (with 10, 50 and 100mM Zn from ZnSO4 and 10, 50 and 100mM P from KH2PO4, respectively) on seed vigor, seedling establishment and grain yield of barley were evaluated in laboratory and field conditions (in autumn and spring plantings) in 2005- 2006 cropping season. Laboratory experiments were conducted as factorial on the basis of completely randomized design and field experiment was carried out as y randomized complete block design. Analysis of variance of laboratory data showed that percentages of viable seeds and germination, electrical conductivity (EC) of seed leakages, germination rate, root and shoot dry weight and seedling dry weight were significantly affected by Zn priming. All, but EC, were affected by P priming. Zn×P priming interaction was also significant on all traits. All of these traits decreased, with increasing Zn concentration in priming solutions. However, these qualitative traits increased, with increasing P concentration up to 50 mM. Further increases of P concentration resulted in reducing the traits. Priming in 10 mM Zn, 50 mM P, 100 mM P, 10 mM Zn + 50 mM P and 10 mM Zn + 100 mM P solutions were superior as compared to the other priming solutions, in the laboratory. Thus, these priming treatments were applied on seeds taht were used for autumn and spring plantings. Field traits were not significantly affected by priming treatments in spring sowing. However, in autumn sowing, the highest emergence rate and winter survival was achieved by 100 mM P + 10 mM Zn priming. In general, priming treatments, particularly 50 mM P + 10 mM Zn and 100 mM P + 10 mM Zn improved grain yield of barley up to 41% in autumn planting. Highest biological yield in autumn belonged to 100 mM P priming treatment and was 34% greater as compared with check. In conclusion, priming could icrease grain yield and biological yield in average by 29% and 16%, respectively. Therefore, these priming solutions can be applied to improve field performance of winter barley in rainfed conditions.