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Showing 29 results for Stress
Azam Roumani, Seyed Mohammadreza Ehteshami,
Volume 1, Issue 1 (5-2014)
Volume 1, Issue 1 (5-2014)
Abstract
In order to study the effect of different levels of salinity stress on germination indices and early growth of Trigonella foenum-greacum L., an experiment was conducted in agronomy laboratory of Faculty of Agricultural at the University of Guilan in 2012. The experiment was arranged base on completely randomized design with four replications. The used treatments were different levels of salinity stress due to NaCl (0, -0.2, -0.4, -0.6, -0.8, -1, -1.2, -1.4, -1.6 and -1.8 MPa). Results showed, by increasing of salinity levels, decreased germination percentage, germination speed, germination energy, germination rate index, water percentage of seedling tissue, seedling length, the dry and fresh weight of seedling and vigor index significantly. However, the levels of salinity (-0.2 and -0.4 MPa) increased the dry and fresh weight of seedling in comparing with control by growth stimulation. Moreover, germination rate reduction had increased trend in comparing with control. Results indicated that there was a positive significant correlation between percent of germination and other germination indices except for germination rate. Generally, the results showed fenugreek seed can tolerate salinity amount until -1.2 MPa (38.9 ds/m) in germination time.
Hamdollah Eskandari, Ashraf Alizadeh-Amraie,
Volume 1, Issue 1 (5-2014)
Volume 1, Issue 1 (5-2014)
Abstract
A laboratory experiment was conducted to evaluate the effect of seed priming under salt and drought conditions on seed germination and early seedling development of millet. A factorial experiment (3×2×5) based on completely randomized design with three replications was employed. The first factor was the effect of seed priming (control, hydro priming and KNO3), the second factor was the effect of salt and drought stresses including NaCl and PEG 6000 and the third factor was the effect of osmotic potential levels (-0.3, -0.6, -0.9 and -1.2 MPa). Results showed that germination performance was negatively affected by decreasing osmotic potential. There was a variable germination with different stress condition, in which seeds were able to germinate at all concentration of NaCl but no significant germination was occurred at -0.6 MPa of PEG for no primed and KNO3. However, both seed priming treatments (Hydropriming and KNO3), improved seed germination performance with the clear effectiveness of Hydropriming in improving germination properties under salt and drought conditions. It was concluded that germination inhibition resulted from osmotic effect rather than salt toxicity.
Mansour Taghvaei, Neda Aliolad,
Volume 1, Issue 2 (1-2015)
Volume 1, Issue 2 (1-2015)
Abstract
Trittipyrum is an important annual grass plant for forage production in arid and semiarid regions. The effects of drought stress on Trittipyrum lines were evaluated in the field experiment in a randomized complete block design with a factorial experiment involving three replications in 2012. Treatments were water stress (field capacity (FC), 75% of FC, 50% of FC and 25% of FC throughout the experimental period and 13 primary Trittipyrum lines ((St/b)(Cr/b)F4, (Ma/b)(Cr/b)F4, (Ma/b)(Cr/b)F3, (Ka/b)(Cr/b)F2, (Ka/b)(Cr/b)F3, (Ka/b)(Cr/b)F5, (Ka/b)(Cr/b)F6, La(4b,4d)/b, St/b, Cr/b, La/b, Ka/b, Az/b). The results showed that drought stress had significant effects on seedling traits. Drought stress significantly decreased shoot length, root length, shoot dry weight, root dry weight, seedling dry weight, seedling length vigor index and seedling weight vigor index. The results of mean comparison revealed that (az/b)(cr/b)F5 and Kz/b lines were the most sensitive and the most tolerant lines to drought stress in early vigor stage, respectively. Although the response of Trittipyrum lines was different to drought stress; but the result indicated that Trittipyrum lines are sensitive to drought at emergence stage.
Leila Aslani, Mostafa Mobli, Mohammad Solemani,
Volume 2, Issue 1 (9-2015)
Volume 2, Issue 1 (9-2015)
Abstract
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. The 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 cultivar were placed on filter papers inside sterilized Petry dishes and spermidine solutions were added to them according to each treatment. All petry dishes were placed at a 13°C temperature of the incubator until end of the experiment and germinated seeds were counted daily. The measured traits were the percentage of germination, plumule length, radicle length, the dry and fresh weight of the plumule and radicle. The results showed that treating seeds of ‘Rashid’ cultivar with 0.1 mM spermidine increased the 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 the percentage of germination, plumule and radicle length, the fresh and dry weight of radicle.
Rahele Ahmadpour, Saeedreza Hosseinzadeh, Nezam Armand, Ebrahim Fani, Fariba Noedoust,
Volume 2, Issue 1 (9-2015)
Volume 2, Issue 1 (9-2015)
Abstract
Rapid germination is an important factor determining the final yield. This study was performed to investigate the effects of different levels of methanol and drought stress on germination characteristics of lentil seedlings. The experiment was conducted in completely randomized design with three replications in summer 2014 at the Khatam Alanbia University of Behbahan. The first factor was different levels of methanol equal to 0 (control), 5, 10 and 15 volumetric percentage (v/v), and the second factor we negative water potential in four levels 0, -3, -6 and -9 bar by PEG. Results showed that there was a significant difference between different methanol concentrations regarding germination percentage, germination speed index, plumule and radical length, plumule and radical dry weight, radical area, radical diameter and consumed endosperm (P 0.01). Different levels of methanol caused a significant decrease in germination characteristics compared with to control. Drought stress with -9 bar level significantly decreased germination percentage, germination speed index, plumule and radical length, plumule and radical dry weight, radical area, radical diameter and consumed endosperm compared to other levels. Effects of drought and methanol were significant differences regarding the germination speed index, plumule length, plumule dry weight and consumed endosperm (P 0.05).
Rrahele Aahmadpour, Nezam Armand, Saeed Reza Hossinzadeh,
Volume 2, Issue 2 (2-2016)
Volume 2, Issue 2 (2-2016)
Abstract
This study was performed to investigate interactions of different levels of vermicompost extract and salinity stress on germination characteristics of chickpea seedlings. The factorial experiment was conducted in completely randomized design with three replications. Concentrations of vermicompost extract (0, 5, 10 and 20 volumetric percentage) and salinity levels (0, 30, 60 and 90 mM NaCl). Results showed that there were significant differences (P 0.01) between vermicompost extract and salinity levels regarding germination percentage, radicle length, and shoot dry weight. Salinity stress with 90 (Mm NaCl) level significantly decreased all of the traits compared to the non-stress condition. Effects of vermicompost extract and salinity stress were significant differences (P 0.05) on the germination rate index, radicle length, radicle dry weight and consumed endosperm. vermicompost extract at concentrations of 5 volumetric percentage in moderate salinity stress (30 mM NaCl) and non-salinity stress caused a significant increase (P 0.01) in radicle length, radicle dry weigh and consumed endosperm compared to control.
Ali Ghatei, Ghasem Parmoon, Zahra Amin Deldar, Hadi Ghamary,
Volume 2, Issue 2 (2-2016)
Volume 2, Issue 2 (2-2016)
Abstract
In order to evaluate the effect of hydropriming on seed germination of Vigna radiata under salinity stress, an experiment was arranged in a factorial based on a completely randomized design with three replications in the laboratory of the Agricultural College of the University of Ramin Khuzestan. Treatments were salinity stress at 4 levels (0, 3, 6 and 9 Mmhos) and hydro priming at 3 levels (1, 1.5 and 3 h) and two sizes of seed (small and large seeds) that was carried out by NaCl. Results showed that all of the germination characteristics decreased with increased salinity, but this decrement for seeds that primed at a long time, was less. Also at all characteristics, small seeds, showed better reactions than large seeds. Generally, hydropriming was improved germination characteristics of Vigna radiata under saline conditions. According to this experiment, hydropriming improved germination and establishment.
Fatemeh Aliyari, Ali Soltani, Mehrdad Zarafshar,
Volume 2, Issue 2 (2-2016)
Volume 2, Issue 2 (2-2016)
Abstract
Select the appropriate tree species and compatible with harsh environmental conditions, with a high survival rate and optimal growth, is very important in the principled forestation projects. Offering moisture - temperature - time seed germination model is one of the solutions to the prediction of seed germination patterns as in this study, germination behavior model in four replications of 50 seeds of Cupressus arizonica (dishes 11cm) on the incubator was examined by applying five levels of water stress (0, -0.5, -1, -1.5, -2 MPa) and temperature treatments (10, 15, 20, 25, 30 °C). The results showed that the optimum temperature (To) and the basic temperature (Tb) for germination is 19.23±0.5 and 6.54 ± 0.0 °C respectively, and amount of the hydro time constant (θH) for this species is 0.29±0.11. According to the results, temperature and water potential factors and their interaction affected significantly on time and percent germination. Value of the hydrothermal time model was determined by using θHT= [(Ψ-Ψb (g)) (T-Tb)] tough model that its rate was 126.3 MPa°C. d with 0.87 coefficients of determination.
Nasrin Farhadi, Ahmad Estaji, Saeedeh Alizadeh Salteh,
Volume 3, Issue 1 (8-2016)
Volume 3, Issue 1 (8-2016)
Abstract
The seed pretreatment with salicylic acid has an important role in improving seed germination and increasing plant resistance to environmental stresses. This study was performed to investigate the effect of salicylic acid on seed germination of Milk thistle under salinity and drought stress. A factorial experiment was conducted in a completely randomized design with three replications. Treatments consisted of 4 levels of salicylic acid (0, 100, 200 and 300 mg/l) and four levels of each drought and salinity stress (0, - 4, - 6, - 8 Bar). The results showed an interaction effect between pretreatment with salicylic acid and drought and salinity stresses was significant at the 1 % level. On high salinity level (-8 Bar), seed germination percentage and rate, root and shoot length, fresh and seedling dry weight reduced significantly. The short length, fresh weight and percent germination reduced in all three levels of drought stress. Pretreatment with salicylic acid (200 and 300 mg/L) significantly reduce the harmful effects of drought and salinity stress (-6 and -8 Bar) on germination and seedling growth parameters of Milk thistle. The results of this experiment showed that seed treatment with salicylic acid can lead to increase the resistance of Milk thistle to salinity and drought stress in seed germination.
Somayeh Rastegar, Akbar Peikari,
Volume 3, Issue 1 (8-2016)
Volume 3, Issue 1 (8-2016)
Abstract
In order to study the salt tolerance of three species, Coreopsis grandiflora, Celosia cristata and Matthiola incana in germination stage, an experiment was carried out based on a completely randomized design with three replications in Hormozgan University laboratory in 2015. Salinity levels, including 3, 6, 9, and 12 dS/m were applied by dilution seawater and distilled water used as a control. In this research, some seed germination indices such as germination percentage, germination rate and mean germination time, length, fresh and dry weight of seedling, seed vigor germination, were measured. Germination percentage, germination rate, seed vigor and dry weight of Coreopsis grandiflora seedling, were significantly different compared with control. In Celosia cristata, germination percent, seed vigor germination and seedling length didn’t show a significant difference in 9 dS/m salinity. In more characters, significant increases were seen with increasing salinity (9 dS/m). Germination percentage was decreased in comparisons with control (24.6%). In addition, the fresh and dry weight of seedling didn’t show a significant difference. The effect of salinity on seed germination of Matthiola incana in a different level of salinity was not significant. Although seed germination decreases gradually by salinity. In general, according to the observed results, Coreopsis grandiflora and Celosia cristata showed more tolerance to salt in comparison with Matthiola incana.
Asad Masoumi Asl, Zohreh Chahabkar, Sakineh Khalili, Reza Amiri-Fahliani,
Volume 4, Issue 1 (9-2017)
Volume 4, Issue 1 (9-2017)
Abstract
Salinity is one of the environmental stresses limiting rice cultivation. Evaluation of the tolerance and sensitivity of offsprings of segregated generations under salinity condition is one way of finding tolerant cultivars. In order to study the effects of salinity (80 mM NaCl) stress on the second generation offspring of crosses of three rice varieties (Dollars and Gharib with 304) and to compare them with their parents and their classification in terms of salinity stress, the first experiment was conducted, adopting a Completely Randomized Design with four replications (i.e., crossing parents with Yasouj and Kamfirooz varieties). In the second experiment, check cultivars and the second generation progeny were evaluated, using an augment with a completely randomized design. At the germination stage, the Dollar cultivar was sensitive to salinity stress because it had the lowest ratio of all traits except germination percentage. However, Gharib and Kamfirooz Cultivars were salt tolerant. In both crosses, second-generation offsprings showed genetic variations in terms of the traits measured. Broad-sense heritability values for Dollars×304 and Gharib×304 crosses for shoot height (5.98% and 96%), root length (8.90% and 86%) and shoot fresh weight (8.95% and 7.92%), were relatively high, indicating that we can select these traits based on their phenotypes. General irritability for the shoot and root length traits in the second generation offsprings of Dollar and 304 crosses was higher than that of the second generation progeny of 304 and Gharib crosses. Based on these results, we concluded that for the purpose of improving salt tolerance at germination stage, 304 and Dollars crosses are more useful in rice breeding programs.
Highlights:
- For the first time, an augment design was adopted in an experimental study to investigate the non-repeat genotypes in the generations.
- The tolerance and sensitivity of genotypes were evaluated, consistent with the definition of statistical intervals.
- The results of this research led to the introduction of superior crossings for replications at the farm level.
Seyedeh Arhameh Fallah-Shamsi, Hemmatollah Pirdashti, Aliakbar Ebadi, Masoud Esfahani, Mahmood Raeini,
Volume 4, Issue 1 (9-2017)
Volume 4, Issue 1 (9-2017)
Abstract
In order to study drought stress effect at the reproductive stage on seed germination characteristics of seven rice genotypes, an experiment was carried out at Sari Agricultural Sciences and Natural Resources University in 2014. This study was conducted on drought-stressed seeds and seeds grown under normal conditions. The results of orthogonal mean comparison among non-stressed seeds showed that local genotypes had a lower germination index, germination rate, water percentage of seedling tissue, shoot length and root dry weight than the improved genotypes. Among stressed seeds, however, local genotypes had a higher germination index and germination rates than those of improved genotypes. Comparison of non-stressed seeds of susceptible and tolerant genotypes indicated that susceptible genotypes had a higher germination index, germination rate and germination percentage than tolerant genotypes. On the other hand, the comparison of the stressed seeds of susceptible and tolerant genotypes revealed that drought stress increased the time to 10, 50, 90 and 95% germination, water percentage of seedling tissue and plantlet length in susceptible genotypes, which were higher than those of tolerant genotypes. In conclusion, it seems that drought stress at reproductive stage has a significant effect on germination characteristics of the plant’s following generation. However, their responses are different, depending on the level tolerance of the genotype to stress and genetic origin.
Highlights:
1- Drought stress at reproductive stage has a significant effect on germination characteristics of the following generation of the rice plant.
2- Among stressed seeds, local genotypes have a higher germination index and germination rates than those of the improved genotypes.
3- Drought stress increases the time of germination in susceptible genotypes, which is higher than that in the tolerant genotypes.
Highlights:
1- Drought stress at reproductive stage has a significant effect on germination characteristics of the following generation of the rice plant.
2- Among stressed seeds, local genotypes have a higher germination index and germination rates than those of the improved genotypes.
3- Drought stress increases the time of germination in susceptible genotypes, which is higher than that in the tolerant genotypes.
Shirin Taghi Zoghi , Elias Soltani , Iraj Alahdadi , Reza Sadeghi ,
Volume 4, Issue 2 (3-2018)
Volume 4, Issue 2 (3-2018)
Abstract
This study was conducted to study the effects of different priming methods on germination rate and percentage under salinity stress and to determine the stability of primed seeds. In order to accomplish this, three different experiments were conducted separately, including the experiment of water uptake, the experiment of salinity stress, and the experiment of storability of primed seeds. Priming treatments were five levels of control (unprimed), hydropriming (Hyd), priming with humic acid (HA), priming with salicylic acid (SA) and priming with gibberellic acid (GA). Salinity stresses were four levels of 0, 4, 8 and 12 ds/m of NaCl. The stability of prime seeds was investigated over a period of 226 days after priming. The results of water uptake showed that rapeseeds entered into the third phase of water uptake after 18 hours of hydration. The results of the salinity experiment showed that salinity levels of 12 and 0 ds/m had the lowest (74.3 %) and highest (83 %) germination percentage, respectively. In terms of germination rate, there were significant differences between GA (0.034 h-1), HA (0.036 h-1) and Hyd (0.036 h-1) with C (0.019 h-1) and SA (0.027 h-1). Generally speaking, primed seeds germinated better than control seeds at all levels of salinity. The storability of primed seeds and control seeds had no significant decrease during storage. Finally, it was concluded that seed priming increased the tolerance to salinity stress; in terms of storability, there was no significant difference between primed seeds and primed seeds could be stored in the same way as control seeds.
Highlights:
- At the current research, the stability of prime seeds was investigated for the first time.
- There was no significant difference between the storability of primed seeds and control (unprimed) at each sampling time (with an exception for SA).
- Primed seeds had better germination performance than control at the all salinity stress levels.
- Seed priming treatments using gibberellic acid, humic acid and hydropriming were the best compared with the other treatments.
Ali Namvar, Raouf Seyed Sharifi, Hashem Hadi,
Volume 4, Issue 2 (3-2018)
Volume 4, Issue 2 (3-2018)
Abstract
In order to study the effects of different levels of salinity on germination components of wheat cultivars, a factorial experiment was conducted based on a completely randomized design with three replications. Experimental factors were wheat cultivars at eight levels (Saysons, Gaspard, Finkan, MV-17, Chamran, Sardari, Atila-4 and Azar-2) and six levels of salinity (0, 25, 50, 100, 150 and 200 mM NaCl). The results indicated that salinity had significant effects on all of the traits studied (i.e., radicle length and dry weight, plumule length and dry weight, remaining seed weight after germination, seedling weight, the longest radicle and plumule, number of radicle per seed, ratio of radicle weight to plumule weight and rate, and uniformity and percentage of germination). All of these traits declined with an increase in the salinity (except the ratio of radicle weight to plumule weight, remaining seed weight after germination and seedling weight). The highest ratio of radicle weight to plumule weight, remaining seed weight after germination and seedling weight were recorded in the salinity of 200 mM NaCl. The cultivars showed significant effects on all of the traits studied (except remaining seed weight after germination and seedling weight). Chamran cultivar showed the highest number of radicle per seed, the ratio of radicle weight to plumule weight, rate and percentage of germination. The highest radicle length and the longest radicle were obtained from the Sardari cultivar while in Azar-2 cultivar it was vice versa in plumule. Atila-4 cultivar showed the highest radicle and plumule weight. It seems that compared with other cultivars, out of the cultivars studied, Chamran, Azar-2, Sardari and Atila-4 were more resistant to salinity stress.
Highlights:
- Introduction of wheat cultivars with more tolerance to salinity conditions at germination stage.
- Study of eight different wheat cultivars in terms of germination indices under salinity stress conditions.
Samaneh Hosseini, Mohammad Rafieolhossaini, Parto Roshandel,
Volume 5, Issue 1 (9-2018)
Volume 5, Issue 1 (9-2018)
Abstract
Extended abstract
Introduction: Niger with the scientific name of Guizotia abyssinica (L.F.) Cass. belongs to the Asteraceae family. Niger seed contains 50-75 percentage of oil which is used in the treatment of rheumatism and burns, and as a substitute for olive oil. Its meal is also used for animal feeding. Environmental crises sustained by living systems are considered as stress. Drought stress is one of the non-biological stresses. Yield reduction due to this type of stress is reported to be higher than that related to other stresses. Since plant development starts from germination and for survival, the seeds should germinate to adapt themselves to the environmental conditions and establish themselves in the soil, the success of passing the germination stage will play an important role in other stages of plant establishment. Different studies have shown the positive effect of magnetic field on increasing germination characteristics. In this regard, applying a magnetic field before planting is a safe and inexpensive method for increasing germination and seedling growth. Seed priming is useful for a faster and more powerful response to drought stress and among different types of priming, physical priming is of particular importance for ecological reasons and for not having a negative impact on the environment.
Materials and Methods: In order to study the effect of seed physical pre-treatment and drought stress on seed germination characteristics of Niger, an experiment was conducted as factorial in a completely randomized design with three replications at the Research Laboratory of Seed Science and Technology at Shahrekord University. Different magnetic field intensities at five levels including (0, 50, 100, 150 and 200 mT (at 5 minutes period)) as the first factor and drought stress at five levels (0, -4, -5, -6 and -7 bar Polyethylene Glycol6000) as the second factor were considered.
Results: The results of variance analysis showed that the effect of drought stress, magnetic field intensity and their interaction were significant on all of the evaluated characteristics. The maximum germination percentage and rate and the minimum of T10 and T50 were observed in 50 mT field intensity under normal conditions. The minimum germination index under normal conditions and the maximum length and shoot dry weight under non-treatment conditions and the maximum root and shoot fresh weight in 200 mT field intensity under normal conditions were obtained. The maximum root length and dry weight were observed in 50 and 100 mT field intensity under normal conditions, respectively.
Conclusions: Seeds which cross through a magnetic field, become swollen and probably as a result, the activity of auxin hormone in these seeds increases. In addition, the respiration level also increases in them and they have higher levels of energy and activity, which results in faster and more uniform germination and the creation of stress-resistant plants. In this study, although by increasing drought stress intensity, negative effects were observed on germination characteristics, the magnetic field under these conditions improved some germination characteristics. In general, for the purpose of improving germination and alleviating drought stress conditions, for 0, -5 and -7 bar potentials, the field intensity of 50 mT and for -4 and -6 bar potentials, the field intensity of 150 mT are recommended.
Highlights:
- The effect of magnetic field on germination of multipurpose seed of Niger plant.
- The effect of drought stress on germination of multipurpose seed of Niger plant, given Iran’s being located in dry belt.
- The positive effect of magnetic field on germination of Niger seed to improve the negative effects of drought stress.
Hasan Teimori, Hamidreza Balouchi, Ali Moradi, Elias Soltani,
Volume 5, Issue 2 (3-2019)
Volume 5, Issue 2 (3-2019)
Abstract
Extended abstract
Introduction: Seed germination is one of the first important and complex stages in the plant life cycle and is affected by many hereditary and environmental factors. Various factors affect germination and seedling establishment. Among these factors are the characteristics of the maternal plant (nutrition, genetics), seed treatment stage at harvest time, as well as environmental factors (temperature, water potential, and ventilation and soil compaction). Also, under the influence of seed loss during storage, seed vigor, which is known as the first component of seed quality, decrease. The aim of this study was investigation of germination and biochemichal responses of the aged seed of Fenugreek to different temperature and humidity ranges.
Materials and Methods: This experiment was conducted as a factorial based on a completely randomized design with four replications in the Laboratory of Seed Science and Technology, Faculty of Agriculture, Yasouj University in 2016. The experimental treatments consisted of nine levels of temperature (5, 10, 15, 20, 25, 30, 35, 40 and 45 degrees Celsius), water potential included seven levels (zero (control), -0.2, -0.4, -0.6, -0.8, -1 and -1.2 MPa) and seed aging at two levels (no aged (control) and aged seed).
Results: In this experiment, the effect of seed aging, water potential and their interactions on each environment on germination indices (germination percentage and germination rate, length and weight vigor index) and biochemical indices (soluble sugar, proline, soluble protein and catalase enzymes) of Fenugreek seeds were significant. The results showed that in the aged seed the germination percentage and rate and seedling vigor index tended to decrease with water potential reduce in temperature lower and higher than 20 degrees Celsius, and the amount of biochemical components of the seed (soluble sugar, soluble protein, proline, and catalase enzyme) also increase.
Conclusion: In general, germination and biochemical indices of seed of Fenugreek are sensitive to water potentials, aging, and seed germination temperatures, respectively. In terms of osmotic potential decrese, the germination temperature of less than 20 ° C resulted in increased germination resistance of fenugreek seed to a more negative water potential.
Highlights:
- Study of germination and biochemical properties of fenugreek seed aged under different level of osmotic potantials and temperatures.
- In areas with a lower osmotic potential it is better to cultivate Fenugreek seed at temperatures below 20 °C.
Forough Hajivand Ghasemabadi, Hamid Reza Eisvand, Naser Akbari, Omid Ali Akbarpour,
Volume 6, Issue 1 (9-2019)
Volume 6, Issue 1 (9-2019)
Abstract
Extended Abstract
Introduction: Agriculture has been influenced by different abiotic stresses such as temperature, drought and salinity, which reduces roughly half of the yield of crops. In many forage plants, germination and early seedling growth are the most sensitive stages of their growth in the face of environmental stresses. Current research was conducted to study the effects of drought and salinity iso-osmosis stresses on germination indices and growth parameters of three clover species, including Trifolium resupinatum, T. alexandrinum and T. incarnatum.
Material and Methods: Two separate experiments (drought and salinity) were conducted as a factorial experiment based on a completely randomized design with three replications. The test factors included clover species with three levels, including T. resupinatum, T. alexandrinum and T. incarnatum and different levels of drought and salinity potentials (0, -2, -4, -6, -8, -10 and -12 bar) due to polyethylene glycol 6000 (PEG 6000) and sodium chloride (NaCl), respectively. Sterile disposable petri dishes with a diameter of 10 cm were used, in each of which, 27 seeds were placed on filter paper and then 5 ml of the desired treatment solution was added to each. Petri dishes were then placed in a germinator at 20°C and relative humidity of 75%. After the end of the desired time germination (About 14 days), from each petri, germination percentage and rate, number of secondary roots, time to get 50% germination (D50), root to shoot ratio and the number of abnormal seedlings were recorded.
Results: Inhibitory effects of salinity and drought stresses affected all germination indices. Germination percentage, rate of germination, root and shoot length all decreased with increasing stress levels, while time to get 50% germination (D50) increased with the increase in stress levels. Under both drought and salinity, all growth parameters of Trifolium resupinatum were higher than the other two species. Germination percentage of T. incarnatum was 0% at -12 bar of drought, but germination of T. resupinatum and T. alexandrinum was 70.33% and 7.33% at -12 bar of these stresses, respectively. Under salinity conditions, all the seeds of the three species germinated at -12 bar. Root to shoot ratio increased with increasing stress levels and at high stress levels, it decreased. The decreases were 41.39% and 0% in drought and salinity, respectively. The number of secondary roots increased with increasing stress levels and the maximum number was observed in Trifolium alexandrinum which was 5.42 and 1 in drought and salinity, respectively. The number of abnormal seedling increased with increasing salinity levels, while under drought conditions there was no abnormal seedling.
Conclusion: Comparison of the effects of sodium chloride and polyethylene glycol showed that sodium chloride reduced germination index due to toxic effects or osmotic effects more than polyethylene glycol solution. It seems that Trifolium resupinatum has the best yield in both drought and salinity stresses, and that in drought condition, Trifolium alexandrinum, and in salinity stress, Trifolium incarnatum have the best performance.
Highlights:
- Introduction of clover species with more tolerance to drought and salinity in germination stage.
- Evaluation of germination indices of clover species under drought and salinity iso-osmotic conditions.
Habib Nejadgharebaghi, Esfandiar Fateh, Amir Aynehband,
Volume 6, Issue 1 (9-2019)
Volume 6, Issue 1 (9-2019)
Abstract
Extended Abstract
Introduction: Strangle wort (Cynanchum acutum) is a perennial weed that could be propagated by seeds and vegetative organs. This brings about harvesting problems for some crops such as cotton, sugar beet, wheat and maize. In recent years, this weed has caused huge losses in sugar cane fields. The role of environmental conditions in weed management is highly important. Given this, the present study seeks to investigate the effects of environmental conditions (salinity and drought stress) on germination characteristics of strangle wort weed.
Materials and Methods: In order to investe the effect of different salinity and drought levels on strangle wort (Cynanchum acutum), two seperate experiments were conducted at Hakim Farabi Khuzestan Sugar Cane Research Institute in 2014-2015. The experimental design was completely randomized, with four replications. The treatments were different salinity levels at 8 levels (0, 2.5, 4.5, 6.5, 8.5, 12.5, 16.5 and 20.5ds/m) and the second experiment involved different drought stresses (osmotic potential) at 7 levels (0, -1, -3, -6, -9, -12 and -15 bar).
Results: The results of salinity stress experiment showed that with increases in salinity levels from 0 to 20.5 ds/m, germination, radicle length, plumule length and seedling weight decreased by 61, 80, 91 and 99%, respectively. The results of drought stress experiment showed that with increases in salinity levels from 0 to -15 bar, all studied traits, i.e., germination, radicle length, plumule length and seedling weight all decreased by 100%.
The analysis of variance results showed that in all the traits, there were significant differences between salinity and drought stress in 1% probability level. In this research, in the salinity experiment, in most of traits, especially radicle length quickly decreased after 8.5 ds/m salinity to higher levels and in drought stress experiment, after -3 bar to higher levels.
Conclusion: On the whole, it seems that sufficient information about this weed is vital for the adoption of the best control method, and gaining insights into how strangle wort responds to environmental stress, especially salinity stress, could help us to come up with new control approaches for this invasive weed. This can present a proper ecological approach that could be adopted in sustainable agriculture programs, which is environmentally sound as it decreases the use of chemical inputs. In addition, in order to lower the tolerance of this weed to salinity and especially drought stress, it is suggested that it be used for weed management programs. According to the results of this study, soil salinity higher than 8.5 ds/m and drought tension above than -3 bar can cause sizeable reduction in most traits (growth parameters) especially in root length. In most of the traits scrutinized, the tolerance of the weed to salinity and drought stress was 12.5 ds/m and -6 bar, respectively.
Highlights:
- Evaluation of germination characteristics of strangles wort under salinity and drought stress conditions.
- Determination of tolerance threshold of strangles wort germination seed to salinity and drought stress.
Majid Ghanbari, Ali Mokhtassi-Bidgoli, Kamran Mansour Ghanaei-Pashaki, Soheil Karamniya,
Volume 7, Issue 1 (9-2020)
Volume 7, Issue 1 (9-2020)
Abstract
Extended abstract
Introduction: Legumes are the most important source of plant protein and Mung bean has a high nutritional value for humans, as it produces seeds containing high protein percentage. The major problem of salinity in seed germination of higher plants is due to excessive amounts of sodium chloride, osmotic pressure, disruption of nutrient uptake and transport, and direct effects of ionic toxicity on the membrane and enzymatic systems that in turn reduce germination. External use of methyl jasmonate can modulate the effects of various stresses, such as salinity and drought, by increasing the antioxidant activity of the seed. Therefore, the purpose of this research was to evaluate the effect of methyl jasmonate and salinity stress on germination and enzymatic properties of Mung bean.
Material and Method: This study was conducted as factorial based on a completely randomized design with three replications during 2015-16 at the laboratory of Department of Agronomy, Tarbiat Modares University. The experimental treatments included four methyl jasmonate solution (0, 50, 100 and 150 mM) and four salinity stress levels (0, 2, 4 and 6 dS/m salinity from NaCl). Petri dishes were placed in a germinator at 25 ° C and in full darkness for 14 days. In this experiment, germination rate and percentage, time to reach 50% germination, alpha and beta amylase, catalase and peroxidase were measured.
Results: The results of the experiment showed that the lowest rate of slope and final germination percentage were obtained in 50 and 100 mM solutions of methyl jasmonate. In terms of T50, an increase of 4.7 days was observed per one dS/m increase in salinity stress and the lowest T50 was estimated at a methyl jasmonate solution concentration of 78.68 mM. In terms of the activity of germination enzymes, reduction of 0.031 μmol/ml/min per 1 dS.m increase in salinity stress and the highest amount of α-amylase were estimated 72.6 μmol/ml/min at a methyl jasmonate solution concentration of 73.33 mM. Also, the lowest activity of β-amylase enzyme was 0.79 μmol/ml/min at a concentration of 5.6 dS/m salinity stress and the highest activity of β-amylase enzyme was estimated to be 1.7 μmol/ml/min at a methyl jasmonate solution concentration of 86.67 mM. The highest activity of catalase (25.7 ∆A/mg protein/min) was observed at 14.72 dS/m salinity stress and the lowest activity of catalase enzyme (8.9 ∆A/mg protein/min) was estimated at 5.88 mM methyl jasmonate solution. The highest activity of peroxidase enzyme (22.06 ∆A/mg protein/min) was at 24.3 dS/m salinity stress and the lowest activity of the enzyme peroxidase (2.5 ∆A/ mg protein/min) was determined at a methyl jasmonate solution concentration of 266.66 mM.
Conclusions: In general, pre-treatment of methyl jasmonate can reduce the germination time, increase the rate of germination and reduce the oxidative stress in salt stress conditions by improving the activity of germination enzymes, increasing the activity of enzymes, increasing the activity of hydrolyzing enzymes and increasing the easy availability of seedlings to nutrients during germination.
Highlights:
1- Germination rate and percentage and morpho-physiological changes of Mung bean seed as affected by methyl jasmonate were investigated.
2- The role of alpha and beta amylase germination enzymes in accelerating the production of Mungbean seedlings under saline conditions were estimated.
3- Methyl jasmonate- induced catalase and peroxidase enzymes activity in resistance to salinity stress were estimated.
Asgar Ganje, Ali Ebadie, Ghasem Parmoon, Soodabeh Jahanbaksh,
Volume 7, Issue 2 (3-2021)
Volume 7, Issue 2 (3-2021)
Abstract
Extended Abstract
Introduction: Water deficit stress is one of the important factors affecting seed germination. This stress decrease germination rate and affects germination percentage under high levels as well. Seed priming improves germination by changing metabolic activities before radicle emergence. This investigation was conducted to evaluate the effect of seed priming by salicylic acid on the emergence index and grain weight of spring wheat under water deficit stress.
Material and Method: These experiments were conducted as factorial based on the completely randomized design with three replicates in the greenhouse of the Faculty of the Agriculture Sciences University of Mohaghegh Ardabili. Experiment treatments included different salicylic acid concentrations (0, 1, 2 mM) and water deficit stresses (25%, 45%, 65% and 85% Field capacity).
Result: According to results, emergence index (emergence percentage and emergence rate, uniformity emergence, and times to 10, 50, and 90% emergence) was influenced at 1% by water deficit stress. The effect of salicylic acid was significant on the emergence index. The interactions of water deficit stress and salicylic acid were effective at 1% on emergence uniformity and time to 90% emergence. Changes in plant height and heading rate were lower under water deficit stress. Also, both slope (b) and maximum content (a) decreased by water stress (22% and 7%). Priming by salicylic acid at 2 mM had the highest effect on both traits and resulted in a decrease in their slopes (17% and 13%) and an increase in their maximum content (34 and 10%). Plant dry weight was influenced by the interactions of water deficit stress and salicylic acid at 5% level. The plant's final height and grain weight was influenced by water deficit stress and salicylic acid. The highest grain weight was obtained at 80% and 60% field capacity with means of 0.79 and 0.75 g, which had no significant differences with eachother. The heights grain weight (0.72 g) was obtained by application of 2 mM salicylic acid which led to an increase of 250% compared to control.
Conclusions: Overall, we showed that water deficit stress resulted in decreased emergence rate and emergence percentage of wheat and finally declined plant growth and grain weight. Application of salicylic acid in seed priming resulted in improvement in the emergence index, growth, and grain weight of wheat. Also, the highest grain weight was observed at 2 mM concentration and it can be considered as the enhancing treatment.
Highlights:
1- Response of plant growth stage to stress was quantified using nonlinear regression
2- Relationship between emergence and grain weight was investigated under stress and priming by salicylic acid.
Introduction: Water deficit stress is one of the important factors affecting seed germination. This stress decrease germination rate and affects germination percentage under high levels as well. Seed priming improves germination by changing metabolic activities before radicle emergence. This investigation was conducted to evaluate the effect of seed priming by salicylic acid on the emergence index and grain weight of spring wheat under water deficit stress.
Material and Method: These experiments were conducted as factorial based on the completely randomized design with three replicates in the greenhouse of the Faculty of the Agriculture Sciences University of Mohaghegh Ardabili. Experiment treatments included different salicylic acid concentrations (0, 1, 2 mM) and water deficit stresses (25%, 45%, 65% and 85% Field capacity).
Result: According to results, emergence index (emergence percentage and emergence rate, uniformity emergence, and times to 10, 50, and 90% emergence) was influenced at 1% by water deficit stress. The effect of salicylic acid was significant on the emergence index. The interactions of water deficit stress and salicylic acid were effective at 1% on emergence uniformity and time to 90% emergence. Changes in plant height and heading rate were lower under water deficit stress. Also, both slope (b) and maximum content (a) decreased by water stress (22% and 7%). Priming by salicylic acid at 2 mM had the highest effect on both traits and resulted in a decrease in their slopes (17% and 13%) and an increase in their maximum content (34 and 10%). Plant dry weight was influenced by the interactions of water deficit stress and salicylic acid at 5% level. The plant's final height and grain weight was influenced by water deficit stress and salicylic acid. The highest grain weight was obtained at 80% and 60% field capacity with means of 0.79 and 0.75 g, which had no significant differences with eachother. The heights grain weight (0.72 g) was obtained by application of 2 mM salicylic acid which led to an increase of 250% compared to control.
Conclusions: Overall, we showed that water deficit stress resulted in decreased emergence rate and emergence percentage of wheat and finally declined plant growth and grain weight. Application of salicylic acid in seed priming resulted in improvement in the emergence index, growth, and grain weight of wheat. Also, the highest grain weight was observed at 2 mM concentration and it can be considered as the enhancing treatment.
Highlights:
1- Response of plant growth stage to stress was quantified using nonlinear regression
2- Relationship between emergence and grain weight was investigated under stress and priming by salicylic acid.
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Site Keywords
Seed Science and Technology, Seed Physiology, Seed Ecology, Modeling, Seed Health, Germination Characteristics, Seed Dormancy, Seed Ageing, Seed Storage, Seed PrimingVote
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