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Goudarz Ahmadvand, Masoume Dehghan Banadaki, Javad Alimoradi, Sara Goudarzi, Sasan Ardalani,
Volume 4, Issue 2 (3-2018)
Volume 4, Issue 2 (3-2018)
Abstract
Salt and drought are two major environmental stresses that affect growth and development of plants. In order to study the effects of sodium chloride and polyethylene glycol (6000) on germination characteristics and early seedling growth of redroot pigweed (Amaranthus retroflexus), two completely randomized designs with 4 replications were conducted at Weed Research Laboratory of Bu-Ali Sina University, Hamedan in 2015. The treatments were salt and drought stress as osmotic potential at six levels (zero (control), -2, -4, -6, -8 and -10 bar). The results showed that when stress increased, germination percentage, germination speed, radicle and plumule length, seedling length and seedling vigor index decreased significantly (p≤ 0.05). With an increase in the intensity of salt and drought stress from zero to -10 bars, redroot pigweed seed germination reduced about 96 and 100 percent, respectively, compared with the control. The highest seedling length in both stresses was observed in the control (7.71 cm) and by increasing stress intensity to -10 bars in both salinity and drought stresses, seedling length was reduced to 1.52 cm and 0 cm, respectively. Fitting of the three-parameter logistic model provided a successful estimation of the relationship between salt and drought stress levels and germination percentage of redroot pigweed as well as germination speed. This model showed that salinity and drought stress at -3.58 and -3.75 bars caused a 50% reduction in maximum germination percentage of redroot pigweed. In addition, 50% decrease in germination speed caused by salinity and drought stress was observed in -2.58 and -2.88 bars, respectively.
Highlights:
- The germination characteristics of redroot pigweed were studied under salt and drought stresses.
- Drought stress reduced germination percentage of redroot pigweed.
Jamal Kiani, Ali Abbasi Surki, Abdulrazagh Danesh Shahraki,
Volume 5, Issue 1 (9-2018)
Volume 5, Issue 1 (9-2018)
Abstract
Extended abstract
Introduction: Drought stress is one of the major problems in sugar beet production in Iran, and is the most important limiting factor for germination and establishment of sugar beet in the early stages of growth. Seed priming with chemical, nutrient elements or pre-chilling techniques are the most effective methods to improve germination percentage and speed, leading to uniform and tolerant seedlings in adverse environmental conditions.
Material and Methods: In order to assess the effect of cold stratification and HCl treatments on the germination of sugar beet seed, cv. Ekbatan, under drought stress conditions, a RCBD factorial experiment with three replications was conducted in Seed Science and Technology Lab of Shahrekord University. The first factor was stratification in two levels; the second factor was seven levels of pretreatments including 2, 4 and 6 hours’ soaking in water and 0.03 HCL accompanied with control, and the third factor was four drought levels (control, -2, -4, -6 bar).
Result: Compared with the control, seed germination percentage and germination rate increased by at least 5-fold, relative germination by 50% and root and shoot length by 10%, due to stratification and duration of exposure to HCl treatments. With no stratification, germination traits increased with increases in exposure time in acid, and the highest values were obtained for the seeds exposed to HCl 0.03 normal for 6 hours. Although under optimal conditions, the effect of HCl was compensated for by stratification, in drought conditions, the highest values were observed in stratified seeds and those placed in acid.
Conclusions: Since successful establishment of sugar beet seedlings at drought stress conditions is critical to achieving optimum density and yield, application of stratification treatments for one week and seed exposure to HCl increased the seed performance under stress conditions. This trend continued to increase with drought stress intensity, and placement of seeds in acid doubled seed germination in -2 bar drought conditions, which continued by 4 times in -6 bar, compared with stratified control seeds. Compared to separate application of the treatments, application of stratification and HCl treatments had synergistic effects on sugar beet seed performance, especially under drought stress conditions.
Highlights:
- Cold stratification and hydrochloric acid treatments increase the efficiency of sugar beet seeds under drought stress conditions.
- Cold stratification and Hydrochloric acid treatment have a synergistic effect on sugar beet seeds.
Farzad Mondani, Ashkan Jalilian, Atusa Olfati,
Volume 5, Issue 1 (9-2018)
Volume 5, Issue 1 (9-2018)
Abstract
Extended abstract
Introduction: Malva (Malva neglecta) is one of perennial plants of the Malvaceae family. One of the most important mechanisms for survival of the plants is dormancy, rest or distance in germination and growth; in this case, despite favorable conditions for germination, the seed remains at rest for an indefinite period of time. Seed dormancy is a consistent feature in some seeds, especially weed seeds to optimize distribution of germination over time. Seed dormancy has a very important role in ecological management. The cause of the physical dormancy lies in skin cells outside tier structure that is impermeable to water. In physical dormancy, the seed coat is so hard that it does not allow the embryo to grow during germination. The chemical dormancy of the plants seeds is caused by the presence of inhibitor substances in the outer shell of many fruits and seeds and may also be due to an Enamel layer that blocks the exchange of oxygen. It goes without saying that understanding the ecology of weed germination and dormancy can contribute to long-term management. Therefore, this study was conducted to determine the effects of breaking seed dormancy and the impact of chemical and mechanical treatments on the germination of the Mallow seeds.
Materials and Methods: In order to recognize the effects of chemical and mechanical treatments on breaking seed dormancy and some of the most important features of seed germination of Malva, the experiment was conducted based on a completely randomized design with 4 replications at Crop Physiology Lab, Razi University, during 2016. Treatments were distilled water (control), sulfuric acid 98% (for 2, 3 and 4 minutes), potassium nitrate 3% (for 3, 4 and 7 days), hydrogen peroxide 30% (for 2, 3 and 4 minutes) and scarification with sandpaper and prechilling (for 1, 2 and 3 weeks). Germination percentage, germination rate, length and dry weight of hypocotyl, length and dry weight of radicle, seedling total dry weight and vigor index were evaluated. Group comparisons, analysis of variance and comparison of means were run based on LSD at 5% level, using SAS software (version 9.4).
Results: The results showed that the highest and the lowest germination percentage were 82% and 5% in scarification with a chilling for 3 weeks and control treatments, respectively. The results of treatment group comparisons also showed that using scarification with a chilling had the greatest impact on seed dormancy breaking. The most hypocotyl length (34.92 mm), hypocotyl dry weight (2.60 g), seedling dry weight (3.29 g) and seed vigor index (58.13) were observed in scarification with a chilling for 3 weeks. The highest germination rate (5.21 in day), radicle length (34.92 mm) and radicle dry weight (0.85 g) also belonged to sulfuric acid 98% for 2 minutes. It seems that seed dormancy of Malva was a combination of physiological and physical dormancy, because the effectiveness of the treatments evaluated in both metabolic and physical processes brought about the increase in the seed germination percentage.
Conclusion: Out of the treatments examined and given the results of group comparisons, scarification with sandpaper and prechilling had the most effect on breaking Malva’s seed dormancy. As scarification with chilling had the main role in breaking seed dormancy, it could be said that the dormancy is physiological and factors contributing to this dormancy are the embryo, the existence of inhibiting factors or both. The results indicated that the germination of Malva (Malva neglcta) seeds mechanically scratched with scarification increased. Therefore, seed dormancy is due to hard coated seeds. The seed coat is as one physical barrier against growth of embryo or radicle that inhibits absorption of water and gas exchanges.
Highlights:
1- Investigating dormancy breaking and germination traits of neglcta species of Malva.
2- Evaluation of efficiency of different chemical and mechanical treatments in the germination traits of Malva.
Ebrahim Gholamalipour Alamdari, Behroz Seifolahi, Zeinab Avarseji, Abbass Biabavi,
Volume 5, Issue 1 (9-2018)
Volume 5, Issue 1 (9-2018)
Abstract
Extended abstract
Introduction: Generally speaking, plants contain various organic compounds which could influence the behavior of plant communities. These compounds are basically secondary metabolites which are found in various parts of plants such as rhizomes, roots, stems, leaves, flowers, fruits and seeds. The objective of the present study was to investigate the hetrotoxicity potential of different organs of Euphorbia maculata weed on traits of germination, chlorophyll and carotenoids pigments of wheat cultivars.
Material and Methods: In this experiment Euphorbia maculate weed was collected at full maturity stage from the Moghan region, located in Ardebil Province. Then various organs of Euphorbia maculate such as stems, leaves, and fruits were separated from each other. Another treatment namely, a mixture of different organs, was also made. This experiment was carried out as a factorial, adopting a completely randomized design with three replications in Weeds Science Laboratory of Gonbad–e- Kavous University in 2017. The first factor was wheat cultivar at two levels, consisting of Morvarid and Gonbad and organs in 5 levels (control, stem, leaf, fruit and their mixture, with equal amount of each) were the second factor. For the bioassay experiment, from each organ and their mixture, 5% suspension (w/v) was prepared, using distilled water. 10 ml of concentrated extract of each organ was applied on 50 sterilized seeds of cultivars of interest in a petri dish containing filter paper. After 7 days, traits such as rate and percentage of germination, radical length, shoot length, seed length vigor index, chlorophyll a, b and total content and carotenoids content were measured.
Results: The results showed that unlike the Morvarid cultivar, germination rate and germination percentage of the Gonbad cultivar significantly decreased, using aqueous extract of various organs of Euphorbia maculata and their mixture. The results also showed that the inhibition effect of fruit and leaf organs on the rate and germination percentage of the Gonbad cultivar were higher than that of other organs and their mixture. According to the results, stem, leaf and fruit extracts had a higher toxic effect on the radical length, compared with the shoot length of the Gonbad cultivar. The results of mean comparison also showed that seed length vigor index of the Morvarid and Gonbad cultivars decreased, due to hetrotoxic compounds of all organs of Euphorbia maculate. In terms of this trait, the highest significant decrease was found in the Gonbad cultivar, which was about 84.13%, compared with the control. In this study, the decreases in the photosynthesis pigments of total chlorophyll and carotenoids in both cultivars with aqueous extract of stem, leaf and fruit organs of Euphorbia maculata were different. The highest decrease of pigments was found in the fruit organ of the Morvarid cultivar. However, aqueous extract of mixed organs had a significant decrease and increase on the content of these pigments in the Morvarid and the Gonbad cultivars, respectively, as compared with the control. This may be due to differences in the quantity and quality of some allelochemicals as well as different reactions of the cultivars.
Conclusions: Given the evidence of the hetrotoxicity potential of various organs of Euphorbia maculata weed on traits of germination as well as the chlorophyll and carotenoids content of wheat cultivars, it is advisable to exploit huge biomass generated by these luxuriantly growing weeds as bio-compounds in sustainable agriculture.
Highlights:
1- Study of allelopathic effect of Euphorbia maculate on various wheat cultivars in farms of the Moghan plain.
2- Aqeous extract of Euphorbia maculate organs significantly reduces germination as well as seedling growth of the Gonbad cultivar.
Ali Abbasi Sourki, Zahra Hosseni, Sina Fallah,
Volume 5, Issue 2 (3-2019)
Volume 5, Issue 2 (3-2019)
Abstract
Extended Abstract
Introduction: Seeds are a good option for propagation and protection of medicinal plants. Although Seed dormancy is an adaptive strategy for wild medicinal plants, but it is considered as an undesirable trait in domestication and cultivation of them, need to be solved. Echinophora platyloba seed has dormancy despite its remarkable medicinal properties.
Materials and Methods: In order to break seed dormancy, three separate experiment including stratification, hormonal treatment and combination of both were performed. For stratification 10 samples of were placed in a wet bed at 5 ° C for 2, 4, 6, 8, 10, 12, 14 and 16 Week and were compared using a completely randomized design with three replications. For hormonal treatment, the seeds were placed in GA concentrations of 0, 500 and 1000 ppm for 24 hours and then transferred to germination conditions. However, since the breaking of dormancy did not occur, this experiment was not discussed any more. For combined application of hormone and stratification, seeds were placed at mentioned concentrations of gibberellin for 24 hours at 20 ° C and then gibberellin solutions were removed and the seed transmitted to 5 ° C and compared for 2, 4, 6, 8 weeks with a CRD factorial experiment with three replications. The first factor was concentration of gibberellin in three levels and the second factor was the duration of stratification in 4 levels.
Results: Stratification had a positive effect on seed dormancy breaking and 16 week chilling lead to highest germination percentage and rate and vigor indices. The combined application of hormonal treatments accelerated dormancy release and improved seed germination characteristics, which peaked at 8 weeks. 8-week stratification treatment at 5 ° C with 1000 ppm gibberellic acid was the best treatment to overcoming of dormancy in Echinophora-platyloba seeds.
Conclusion: It seems that seed dormancy of Echinophora seeds is physiological, which broke down by moist chilling and simultaneous application of stratification and gibberellin successfully. Although Gibberellin had no effect on dormancy break, it reduced the need for stratification. Combined application of them showed synergistic effects on dormancy release.
Highlights:
- Echinophora seed’s dormancy was broken under stratification conditions, but GA had no effect on it lonely.
- The application of gibberellin reduced the chilling demands of Echinophora seeds and the combined application of them had a synergistic effect on dormancy break
Seyed Ali Tabatabaei, Omid Ansari,
Volume 5, Issue 2 (3-2019)
Volume 5, Issue 2 (3-2019)
Abstract
Extended abstract
Introduction: Heavy metal pollution is one of the most serious environmental problems. These metals which accumulate in food chain bring about a lot of hazards to both humans and animals. Among heavy metals, lead is considered to be the most dangerous heavy metal in the environment. It contaminates the environment through the lead-acid battery industry, paint and gasoline additives, insecticides, chemical fertilizers, car exhaust pipes and soldering. The objective of this study was to investigate the effect of Pb(NO3)2 on germination characteristics and biochemical changes of two wheat cultivars (Chamran and Kohdasht cultivars).
Materials and Methods: The objective of this research was to evaluate germination and biochemical changes of two wheat cultivars under Pb(NO3)2 stress, using three-parameter sigmoid model. The experimental design adopted was factorial with a completely randomized design, as the base design, with 3 replications. The first factor was 2 wheat cultivars (Kohdasht and Chamran), and the second factor was 6 levels of Pb(NO3)2 (0, 0.25, 0.5, 0.75, 1 and 1.5 mg.L).
Results: The results showed that with increases in levels of Pb(NO3)2 stress, germination percentage, germination rate, normal seedling percentage, seedling length, seedling weight and seed vigor index reduced for both wheat cultivars. The results of fitting three-parameter sigmoidal to characteristics indicated that the highest characteristics and X50 were obtained from the Chamran cultivar. The highest germination percentage (96%), germination rate (23 seeds per day), normal seedling percentage (93.33%), seedling length (13.07 cm), seedling weight (0.07) and seedling vigor index (12.18) were obtained from the Chamran cultivar under non-stress conditions. Pb(NO3)2 stress increased proline and catalase activity but reduced protein, proline and protein for the Chamran cultivar, as compared with the Kohdasht cultivar.
Conclusion: Generally speaking, the results showed that Pb(NO3)2 had a significant effect on germination characteristics and catalase, proline and protein of wheat. Finally, it could be said that in copper-accumulated areas, choosing proper cultivars can slightly mitigate the damages caused by copper. The Chamran cultivar seems to be a better candidate for these conditions.
Highlights:
- Evaluation of the effect of Pb(NO3)2 stress on germination characteristics of wheat.
- Using three-parameter sigmoid model for the evaluation of biochemical changes and germination of wheat under Pb(NO3)2 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.
Maryam Mokhtari, Sina Fallah,
Volume 6, Issue 1 (9-2019)
Volume 6, Issue 1 (9-2019)
Abstract
Extended Abstract
Introduction: In order to take more advantage of the spring growing season, the mechanisms of germination of spring plants are of great importance at temperatures lower than the optimum temperature. Since one of the ways to reduce damage due to low temperature is enhancing the seedling antioxidant system, in this study the effects of salicylic acid and gibberellin on germination and antioxidant system of pumpkin (Cucurbita pepo) seeds were investigated under low temperatures.
Materials and Methods: A factorial experiment including four concentrations of gibberellin (0, 250, 350 and 450 mg/L), four concentrations of salicylic acid (0, 0.5, 1 and 1.5 mM) and three temperature levels (8, 11 and 14 °C) was performed with a completely randomized design within controlled conditions and six replications at Shahrekord University in 2017. The seeds were immersed in containers containing solutions of 0, 250, 350 and 450 mg/L of gibberellin and solutions with 0, 0.5, 1, and 1.5 mM salicylic acid, were placed in a growth chamber for 24 h under dark conditions at 15 °C. Then the seeds were washed at the desired temperatures, and the germination was recorded every 24 hours based on the 2 mm of radicle length. At the end of the eighth day, after the separation of normal and abnormal seedlings, 20 normal seedlings were selected from each petri dish. Following that, the germination rate, germination percentage, soluble protein, malondialdehyde, superoxide dismutase, guiacol peroxide enzyme, and catalase enzyme were measured. Comparison of means was conducted by the least significant difference test at the 0.05 probability level.
Results: The results showed that none of the treatments used at 8 °C helped germination of the plant and, therefore, 8 °C treatment was removed from the experiment. At the temperature of 11 ° C, the use of salicylic acid 1 mM and at 14 °C, the use of gibberellin 350 mg/L showed the maximum germination rate and germination percentage, compared with the control. At 11 °C, the activity of antioxidant enzymes was more affected by gibberellin hormone so that the highest activity of superoxide dismutase enzyme was observed in 350 mg/L and the highest activity of catalase and guaiacol peroxidase enzymes and the lowest amount of soluble protein were observed in gibberellin 250 mg/L. The salicylic acid hormone was more successful at 14 ° C. The salicylic acid 1.5 mM increased the activity of superoxide dismutase enzyme; and salicylic acid 0.5 mM increased the activity of catalase and salicylic acid 1 mM improved the activity of guiacol peroxidase. This hormone also succeeded in reducing the amount of soluble protein.
Conclusion: In this experiment, seedling tolerance at low temperatures was confirmed by gibberellin and salicylic acid treatments. It is generally concluded that the use of gibberellin and salicylic acid increases the activity of antioxidant enzymes and, as a result, makes pumpkin (Cucurbita pepo) seedlings tolerant to low-temperature stress, and thus, can ameliorate the effect of possible chilling on growth of this crop at the beginning of the season.
Highlights:
- Gibberellin and salicylic acid treatments make pumpkin seedling tolerant to low temperatures.
- Application of gibberellin and salicylic acid increases the activity of antioxidant enzymes.
- By using gibberellin and salicylic acid, the effect of possible chilling can be reduced at the beginning of the growing season.
Ebrahim Gholamalipour Alamdari, Rashid Poornamazi, Abbas Biabani, Fakhtak Taliey,
Volume 6, Issue 1 (9-2019)
Volume 6, Issue 1 (9-2019)
Abstract
Extended abstract
Introduction: Interference includes competition for environmental potentials and allelopathy. By releasing chemical compounds, usually of secondary metabolites, in various ways such as root exudation, decomposition, leaching and volatilization, allelopathic weeds may have positive, negative or even neutral effects on crops. Therefore, the purpose of this experiment was to evaluate the hetrotoxic potential of Sorghum halepense, Portulaca oleracea and Centurea depressa in characteristics of germination, chlorophyll content and carotenoid pigments of cress under laboratory conditions.
Materials and methods: For bioassay experiments, various concentrations of 0, 20, 40, 60, 80 and 100% of the weeds such as S. halepense, P. oleracea and C. depressa were prepared with the help of distilled water and were subsequently separately applied on 50 certified seeds of cress. In this experiment, characteristics such as rate and germination percentage, content of chlorophyll a, b, total chlorophyll content and carotenoids were measured based on the chilled acetone method.
Results: Regression model showed that rate and germination percentage of cress significantly decreased at concentrations higher than 80% of S.halepense only. For every unit increase in the concentration, radicle length, seed vigor, content of total chlorophyll and carotenoids of cress decreased about 0.08 cm, 8.68, 0.007 mg/g and 0.007 mg/g, respectively. According to the results, there was an exponential relationship between different concentrations of the P. leracea extract with germination characteristics and photosynthesis pigments of cress so that in most cases, these characteristics up to concentration of 40% had moderate decline, but beyond this concentration, they showed a steep decline. In case of C. depressa, rate and germination percentage, as well as the shoot length of cress decreased about 14.67, 14.67 and 29.81% respectively, using only a concentration of 100%. However, radicle length and seed vigor of cress decreased with increased concentrations of aqueous extract of C. depressa. The most reductive effects were obtained in the treatment of 100%, which were about 52.38 and 55.44% respectively. Amount of total chlorophyll of cress decreased about 14.37, 27.59 and 25.29% respectively in concentrations of 60, 80 and 100% of C. depressa extract, as compared with the control. On the other hand, concentrations of 20 and 40% of C. depressa had no significant effect on the pigment studied. The result of carotenoids content was the same as total chlorophyll.
Conclusions: Based on the results, the weeds studied, especially P. oleracea, with high concentrations, had strong hetrotoxic effect on germination characteristics and photosynthesis pigments. This requires further investigation in a natural environment where targeted plants grow in close proximity.
Highlights:
- Hetrotoxic compounds of Portulaca oleracea, especially in high concentrations significantly decrease seed germination and photosynthetic pigments of cress as compared with Sorghum halepense and Centurea depressa.
- Given the evidence for the hetrotoxic effect of aqueous extract of the weeds studied, they could be introduced as candidates for production of bio-herbicides.
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.
Hosein Sarani, Ebrahim Izadi, Ali Ghanbari, Ali Rahemi,
Volume 6, Issue 1 (9-2019)
Volume 6, Issue 1 (9-2019)
Abstract
Extended Abstract
Introduction: In recent years, Japanese morning glory has been recognized as a new weed in some soybean cultivation areas in the Province of Golestan. Japanese morning glory, an annual herbaceous plant, belongs to Convolvulaceae family. Germination is the first step in the competitiveness of a weed in an ecological niche. Among the factors influencing seed germination, temperature and light are the most important environmental factors. The relationship between temperature and germination rate is mainly determined by nonlinear regression, and various models such as dent-like, segmented, beta, and second-order major models are used for this purpose. In this study, we examined the aspects of germination biology of this weed under the influence of temperature and light.
Materials and Methods: In order to investigate the effect of temperature and light on germination of Japanese morning glory, two separate experiments were conducted. Treatments included constant temperature at 7 levels (10, 15, 20, 25, 30, 35, 40) in the first experiment and alternating temperature at 6 levels (30/25, 10/15, 30/20, 35/25, 40/30, 45/35) and light conditions (14 hours of brightness 250 μmoles/m-2-sec-1) and darkness in the second experiment based on a completely randomized design with four replications. The number of germinated seeds was taken up to 4 days after stopping germination every day. Percentage and speed of germination and time reaching 50% germination were calculated. Three models of dent-like, segmented lines and beta were used to determine the cardinal temperature between the temperature and germination rate.
Results: The results showed that temperature had a significant effect on percentage, speed and time taken to reach 50% (D50) of germination of Japanese morning glory. The highest percentage of germination (95%) and germination rate (19.80 seeds per day) were observed in the alternating temperature of 20/30 ° C treatment, respectively. The lowest percentage of germination (83.33%) was observed at alternating temperatures 25/35 °C, and the lowest germination rate (15.10 seeds per day) was observed at 10-20 °C. The segmented lines, dent-like and beta were best fit based on the highest R2adj 0.95, 0.96 and 0.95, respectively. Light had no significant effect on germination, so that germination occurred under both light and dark conditions. According to the results, Japanese morning glory is able to germinate at a wide range of constant and alternating temperatures, although germination is faster at warmer temperatures. On the other hand, the lack of light for germination is another advantage that increases germination, competition, and expansion in agronomic environments.
Conclusion: The findings of the present study suggest that the highest percentage of germination and rate of germination were observed in alternating temperatures of 20/30 °C respectively. Among the nonlinear regression models, the dent-like model represented the best model for describing the germination rate against the temperature in Japanese morning glory. It seems that this weed has better germination at warmer temperatures. Probably from mid-spring following warmer weather, and upon the availability of water, this weed is in a good situation to germinate and compete. It was also found that light had no significant effect on the germination of this weed.
Highlights:
- Non-photoblastic seeds
- Superiority of dent-like model for predicting germination of Japanese morning glory
Keyvan Maleki, Elias Soltani, Iraj Alahdadi, Majid Ghorbani Javid,
Volume 6, Issue 2 (3-2020)
Volume 6, Issue 2 (3-2020)
Abstract
Extended abstract
Introduction: Conditional dormancy (CD) is a dynamic state between dormancy (D) and nondormancy (ND). Seeds at the conditional dormancy stage germinate over a narrower range of temporal conditions. Conditional dormancy is usually observed in seeds with physiological dormancy. However, primary conditional dormancy has also been seen in some freshly harvested seeds. The purpose of the present study was to investigate whether freshly harvested oilseeds have non-dormancy or conditional dormancy.
Materials and Methods: A factorial experiment was conducted based on a completely randomized design with four replications at Seed Technology Laboratory of Aburaihan Campus, University of Tehran, Iran, in 2018. In this experiment, seeds of rapeseed were collected from 20 different locations in Golestan and Mazandaran provinces. Following that, a germination test was carried out at different temperatures (5, 15, 20, 30, 35°C), and the germination percentage and seed germination rate were recorded. In order to break seed dormancy, two treatments were used: gibberellic acid and after-ripening. For after-ripening treatment, seeds were stored in a paper bag in a dry and dark environment for 6 months. For gibberellic acid treatment, a solution of 100 parts per million (PPM) of gibberellic acid was prepared and added to the Petri dishes. Subsequently, the percentage and rate of germination were recorded.
Results: The results showed that freshly harvested seeds had primary conditional dormancy and germinated in a narrow range of temporal conditions. In addition, cardinal temperatures for freshly harvested seeds were 4.45 and 27.8 for bases and ceilings, respectively. Following gibberellic acid and after-ripening treatments, seeds germinated in a wider range of temperatures and base and ceiling temperatures reached 1.74 and about 40°C, respectively. Thus, germination percentage of seeds treated with gibberellic acid and after-ripening increased at both high and low temperatures. However, the increase in germination percentage was higher at high temperatures than low temperatures. In addition, the effect of gibberellic acid treatment was more than that of after-ripening treatment on the release of dormancy, and after-ripening treatment had an intermediate effect between the gibberellic acid and freshly harvested seeds.
Conclusion: Based on the results of this experiment, the application of gibberellic acid and after-ripening treatments resulted in breaking the dormancy of freshly harvested seeds and increased germination temperature range at high and low temperatures. Of the two treatments, gibberellic acid had the greatest effect on breaking dormancy and increasing temperature range. Among the cultivars, these changes were maximum in the germination capacity of Hyola 50 and Trapar cultivars and Trapar cultivar had minimum changes.
Highlights:
1-Conditional dormancy of oilseed cultivars was investigated under different environmental conditions.
2-Application of gibberellic acid and after-ripening treatments resulted in breaking primary conditional dormancy in oilseed cultivars.
Sepideh Nikoumaram, Naeimeh Bayatian, Omid Ansari,
Volume 6, Issue 2 (3-2020)
Volume 6, Issue 2 (3-2020)
Abstract
Extended abstract
Introduction: Temperature is one of the primary environmental regulators of seed germination. Seed priming technique has been known as a challenge to improving germination and seedling emergence under different environmental stresses. Quantification of germination response to temperature and priming is possible, using non-liner regression models. Therefore, the objective of this study was to evaluate the effect of temperature and priming on germination and determination of cardinal temperatures (base, optimum and maximum) of Brassica napus L.
Material and Methods: Treatments included priming levels (non-priming, priming with water, gibberellin 50 and 100 mg/l) and temperature (5, 10, 15, 20, 30, 35 and 40 °C). Germination percentage and time to 50% maximum seed germination of Brassica napus L. were calculated for different temperatures and priming by fitting 3-parameter logistic functions to cumulative germination data. For the purpose of quantifying the response of germination rate to temperature, use was made of 3 nonlinear regression models (segmented, dent-like and beta). The root mean square of errors (RMSE), coefficient of determination (R2), CV and SE for the relationship between the observed and the predicted germination percentage were used to compare the models and select the superior model from among the methods employed.
Results: The results indicated that temperature and priming were effective in both germination percentage and germination rate. In addition, the results showed that germination percentage and rate increase with increasing temperature to the optimum level and using priming. As for the comparison of the 3 models, according to the root mean square of errors (RMSE) of germination time, the coefficient of determination (R2), CV and SE, the best model for the determination of cardinal temperatures of Brassica napus L. for non-primed seeds was the segmented model. For hydro-priming and hormone-priming with 50 mg/l GA, the best models were segmented and dent-like models and for hormone-priming with 100 mg/l GA, the dent-like model was the best. The results showed that for non-priming, hydropriming with water, gibberellin 50 and 100 mg/l treatments, the segmented model estimated base temperature as 3.54, 2.57, 2.34 and 2.34 °C and dent-model estimated base temperature as 3.34, 2.45, 2.21 and 2.83 °C, respectively. The segmented model estimated optimum temperature as 24.62, 23.23, 23.69 and 24.38 °C. The dent-model estimated lower limit of optimum temperature and upper limit of optimum temperature as 20.01, 19.62, 16.25, 19.87 and 28.81, 27.38, 29.58 and 27.31 °C.
Conclusion: Utilizing non-liner models (segmented, dent-like and beta) for quantification of germination of Brassica napus L. response to different temperatures and priming produced desirable results. Therefore, utilizing the output of these models at different temperatures can be useful in the prediction of germination rate in different treatments.
Highlights:
1-The effect of priming on germination of Brassica napuswas investigated.
2-The temperature range of rapeseed germination of Brassica napus changes with the use of seed priming.
Marziyeh Rostami, Sina Fallah, Ali Abassi Surki, Mohammad Rafieoalhosseini,
Volume 7, Issue 1 (9-2020)
Volume 7, Issue 1 (9-2020)
Abstract
Extended Abstract
Introduction: Plants release much of bioactive chemicals from different parts such as leaves, stems and roots through different mechanisms to their surrounding environement. These biologically active chemicals are often referred to as "allelochemicals". Allelopathic compounds play a major role in reducing germination and the growth of crops.
Materials and methods: In this study, the effect of leaching on the reduction of phytotoxicity effect of soybean, black cumin, dragonhead and dill was investigated on the emergence and early growth of canola (Brassica napus L.). The experiment was conducted as factorial based on a completely randomized design with four replications in 2016. Treatments included four previous crop residue (soybean, black cumin, dragonhead, and dill), and three levels of leaching (without leaching, one-time leaching, and two-times leaching). The leaching-free treatment (control) was sub-irrigated to maintain the uniformity of environment moisture. Five days after the first leaching, the two leaching treatment was irrigated again. Five days after the second leaching, when the soil moisture was suitable for seed planting, 10 seeds of canola were cultivated in each pot at a depth of 3 cm of soil. After three weeks seedlings of canola were removed from the pot and the traits were measured.
Results: The results showed that the growth characteristics of canola, except root length, were affected by the residues of the previous crop. In non-leaching conditions, the residue of the four plants reduced the rate and amount of canola emergence, and the greatest reduction in canola emergence was recorded for the application of black cumin residue (7.5%). In the leaching conditions, the length of canola leaves increased, which was higher in the twice leaching treatment. This trend shows that as the amount of leaching frequency increased, it is highly likely that more inhibitiing materials leave the soil and conditions become suitable for canola germination and growth.. The highest dry weight of canola root was observed in one-time leaching treatment. The dry weight of canola leaf grown in dill and soybean residues was increased as a result of one-time leaching, whereas the dry weight of canola grown in black cumin and dragonhead residues showed a higher increase in two-times leaching. Results show that four studied plants have canola growth inhibiting compounds and leaching can ameliorate this effect. The response of canola in the soil containing black cumin and dragonhead residues is higher in two-times leaching, and in the soil containing plant residues dill, one-time leaching is sufficient. In soils containing soybean residue, the response index was almost similar in case of one and two-times leaching.
Conclusion: Generally, the results showed that the application of leaching before planting canola reduced the inhibitory effects of plant residue on germination and growth of canola. Therefore, it is suggested that in the agricultural ecosystems in which canola is present in crop rotation, cultivation of canola must be avoided in presence of soybean, black cumin, dragonhead, and dill residue to eliminate their inhibitory effects on canola growth. In areas with water restriction, autumn rainfall can act as leaching and reduce the effect of allelopathic compounds. In case leaching is not possible, cultivation of canola inside the residue of these plants must be avoided.
Highlights:
1-Leaching can reduce the effect of allelopathic compounds.
2- Allelopathic compounds of some plants such as black cumin showed better response to two-times leaching.
Fatemeh Lkhoshnoodashkarian, Marjan Diyanat, Gorban Noormohammadi,
Volume 7, Issue 1 (9-2020)
Volume 7, Issue 1 (9-2020)
Abstract
Extended abstract
Introduction: London rocket is an important winter annual weed of the mustard family (Brassicaceae), which is propagated by seed. Germination of a seed population in response to water potential reduction is modeled using the concept of hydro time. This model has outputs that are physiologically and ecologically meaningful. One of the presumptions of the Hydro time model is the normal distribution of the base water potential among the seed population.
Materials and methods: In order to quantify the germination characteristics and determine the cardinal temperature of germination of London rocket (Sisymbrium irio L.), an experiment was done in 2018 at Science Research Branch, Islamic Azad University, Tehran, Iran. The seeds were placed at constant temperatures (5, 10, 15, 20, 25, 30, 35, 40 and 45 °C). Germination percentage, germination rate, root length, shoot length, seedling length and seedling fresh weight were evaluated. Intersected-lines, dent-like and quadratic polynomial models were used to determine cardinal temperatures. London rocket seed germination was tested across a range of water potential (0, -0.2, -0.4, -0.6 and -0.8 MPa) at the optimal temperature of 22.80 °C. The hydro time model, based on the normal distributions was fitted to data.
Results: Results showed that seed of London rocket did not germinate at temperatures of 5, 35, 40 and 45° C, and 25° C was the best temperature for seed germination (48%). The longest root length (4.49 mm) was observed at 20°C, which did not have significant differences with temperatures of 15 and 25 °C. The longest shoot length (10.19 mm) was obtained at 25 °C and there were not any significant differences among this temperature and temperatures of 15 and 20 °C. Similar trend with the trait of root length was observed for the trait of seedling length. The best model for estimating the cardinal temperatures in London rocket was intersected-line model with respect to coefficient of determination and mean square error. According to the intersected-lines model in London rocket, the minimum, optimum and maximum temperatures were calculated 5.83, 22.80 and 37.91°C. According to the hydro-time model based on normal distribution, the hydro-time constant and the base-water potential (which is a threshold for germination beginning) of London rocket degree were 284.28 (MPa/h) and -1.18 (MPa) at 22.80 °C, respectively.
Conclusions: Knowledge of germination and emergence of weeds also helps to predict the potential distribution to new habitats. The obtained coefficient of determination (0.94) between observed germination and predicted germination showed that the hydro time model based on normal distribution fitted well to germination percentage of London rocket seed. Due to the low hydrotime coefficient of this weed and the drought problem that most provinces face, it is expected that this weed will become more problematic in most provinces of Iran in the future.
Highlights:
1- The best temperature for germination of London rocket seed is 25 °C.
2- The best model for estimating the cardinal temperatures in London rocket is intersected-line model
3- The hydro-time constant and the base-water potential of London rocket degree based on normal distribution are 284.28 (MPa/h) and -1.18 (MPa) at 22.80 °C, respectively.
Saeed Sharafi,
Volume 7, Issue 1 (9-2020)
Volume 7, Issue 1 (9-2020)
Abstract
Extended Abstract
Introduction: Germination and seedling establishment are the primary stages of crop growth that are highly sensitive to salinity and drought stresses. On the other hand, seed hardness affects the quality of plant germination. Therefore, the aim of this study was to analyze the effect of seed pre-treatment on germination characteristics of Medicago scutellata var Rabinson.
Material and methods: In the present study, the effects of pre-treatment methods of scarification (sand paper, knife and sand), stratification (0, -5, -10, and -15 °C), ultrasonic waves (3, 6, 9, 12, and 15 min), and magnetic field (two intensities of 125 and 250 mT in 4 times exposure by 6, 12, 18, and 24 h) on seed germination of annual medic germination affected by salinity and drought stresses (0, -3, -6, -9, and -12 bar) were investigated with three replications. Twenty seeds per Petri dish were used for each treatment. Seedlings were incubated in the dark at 20/18±0.3°C in a growth chamber. After ten days, the dry weight of the seedling was obtained after oven drying at 70°C. Root length, shoot length, seed germination percentage, seedling growth rate (SLGR), the weight of mobilized seed reserve (WMSR), seed reserve depletion (SRDP), and seed reserve utilization efficiency (SRUE) were measured.
Results: Based on the preliminary results using Taguchi method, the -15 °C stratification treatments under salinity and drought, 6 and 9 min of exposure to ultrasonic waves under salinity and drought, and magnetic field intensity of 250 mT for 6 and 9 h were chosen for the experiment of salinity and drought, respectively. In salinity experiment, the maximum root length (23.47 mm), shoot length (15.76 mm), weight of mobilized seed reserve (0.119 mg per seed), and seed reserve depletion percentage (58.9 %) was in scarification treatment; the maximum seed germination (47.2 %) was observed in control treatment; the maximum seedling dry weight (0.195 mg) was identified in magnetic field treatment; and the maximum seed reserves utilization efficiency (0.665 mg.mg.seed-1) was obtained in ultrasonic waves treatments. In drought experiment, the maximum root length (22.84 mm), shoot length (8.09 mm), seed germination (49.93 %), the weight of mobilized seed reserve (0.096 mg per seed), and seed reserve depletion percentage (43.1 %) was measured in ultrasonic treatment; the maximum seedling dry weight (0.09 mg) was found in magnetic field treatment; and the maximum SRUE (0.516 mg.mg.seed-1) was observed in control treatment.
Conclusions: According to the results, there is a direct relationship between the decline in seedling dry weight and the decline in the weight of mobilized seed reserve. However, the scarification and ultrasonic waves' treatments had significant effects on seedlings resistance to salinity and drought, respectively. Furthermore, the use of ultrasonic waves and scarification produced higher germination percentage and more vigorous seedlings under drought and saline conditions. In terms of germination and seedling growth, the differences among the treatments increased by the increase in stress intensity. This advantage led to greater seed reserve utilization. Moreover, pre-treatment methods resulted in longer cotyledon length and improvement in vigorous seedlings. Future studies should focus on the study of enzymes activity and/or hormones affecting seed reserve utilization rate in response to drought and salinity stress.
Highlights:
1- The most sensitive growth stage of annual medic (seedling production stage) to salinity and drought stress was evaluated.
2- Various pre-treatments to improve the germination of annual medic to enter crop rotation in arid and semi-arid regions due to self-seeding and short growing period were investigated.
Hadi Pirasteh-Anosheh,
Volume 7, Issue 1 (9-2020)
Volume 7, Issue 1 (9-2020)
Abstract
Extended abstract
Introduction: Camelthorn (Alhagi maurorum) has a high tolerance to salt and water stresses, and its forage quality is greater than cereal straw and is equal to alfalfa. Seeds of camelthorn do not germinate easily due to the hard seed coat. Therefore, camelthorn cultivation as an agricultural crop needs more research, especially on breaking seed dormancy and increasing germination. Despite numerous studies about camelthorn as a weed, there are few studies on evaluating agronomic factors of camelthorn as a field crop. Hence, in this study, some aspects of germination and salinity tolerance of camelthorn were examined.
Materials and Methods: In this research, different aspects of camelthorn germination were examined at the National Salinity Research Center in 2018. In the first experiment, different pretreatments including control, sandpaper, hydro-priming, hot water, and sulphuric acid were assessed. With the selection of sulphuric acid as the best treatment, varying durations (0, 5, 10, 15, 20, and 25 min) and concentrations (98% and 75%) of sulphuric acid priming were compared in the second and third experiments. In the fourth experiment, the seeds collected in 2018 were compared with the seeds collected in 2017 and 2016. The effect of different salt stress levels (0, 6, 12, 18, 24, 30, and 36 dS m-1) was evaluated on camelthorn germination and early growth in the fifth experiment. In the sixth experiment, lighting regimes including continuous dark, continuous light, and an alternative period of dark- light were examined and in the seventh experiment sibling factors (together and individual seeds) were evaluated. Seed germination and seedling length were calculated and salinity tolerance threshold levels and 50% reduction threshold were estimated.
Results: The results of the first experiment showed that the highest germination percentage was obtained in sulphuric acid priming (56.6%), which was six folds greater than the control. In the second experiment, it was shown that the highest germination percentage (81.1%) and seedling growth (5.7 cm) was observed in sulphuric acid priming 98% for 25 min. Important note was that these results were related to domestically produced sulphuric acid, and the highest germination and seedling growth were observed in 75% concentration for the imported sulphuric acid. In the fourth experiment, it was found that at least 3 years of seed longevity had no significant effect on seed germination. Considerable losses in germination and growth were observed from 30 dS m-1 salinity level; however, germination did not completely stop even at 36 dS m-1 salinity. In the sixth and the seventh experiments, it was found that there were no significant differences between seeds germination in the continuous dark, continuous light, and an alternative period of dark- light as well as between individual and together seeds. So, camelthorn seed is not photoblastic and had no negative sibling factor.
Conclusions: Generally, it was concluded that the best method for improving germination is priming with sulphuric acid 98% (internal) or 75% (imported) for 25 min. According to achievement of high germination in sulphuric acid pre-treatments (chemical scarification), it seems that seed dormancy in camelthorn is presumably physical. Furthermore, although the salinity tolerance threshold of this plant is estimated 14.2 dS m-1, it can germinate minimally even in very higher salinity. Light salt stress not only decreases the germination of this plant but also is necessary for growth promoting. Based on the high salinity tolerance of camelthorn in the germination stage, its cultivation in haloculture systems is recommended for more investigation.
Highlights:
1- Sulphuric acid 98% priming for 25 min led to breaking seed dormancy and acceptable camelthorn germination.
2- In moderate salinity, germination was not significantly changed and seedling growth was promoted compared with the non-stress conditions.
3- Salinity tolerance threshold level of camelthorn was estimated 14.2 dS m-1.
Ebrahim Gholamalipour Alamdari, Amir Ghorbani, Hossein Sabouri, Meisam Habibi,
Volume 7, Issue 1 (9-2020)
Volume 7, Issue 1 (9-2020)
Abstract
Extended abstract
Introduction: Without a doubt, plant hetrotoxicity is one of the important factors in determining the distribution and abundance of some species in plant communities. Thus, the purpose of this experiment was to evaluate the effect of phenolic composition obtained from the methanol extract of Echinochola crus-galli on germination traits and cytogenetic behavior of rice.
Materials and methods: This experiment was done to assess hetrotoxic potential of various concentrations (0, 0.024, 0.048, 0.076 and 0.1 mM) of the phenolic composition obtained from the methanol extract of whole-organ of E. crus-galli on germination traits of rice as well as mitosis division of meristematic cells of radicle in a completely randomized design. To extract thephenolic composition, warm extraction method using a methanol solvent was used. For studying mitosis division, first rice seeds were germinated. Then, each of the steps such as fixation, hydrolysis, staining, squashing and microscopic studies were done on the end of the radicle. Mitosis indices and percentage of mitosis inhibition were calculated and also percentage of each of chromosomal abnormalities at four stages of prophase, metaphase, anaphase and telophase as compared to total cells was calculated.
Results: The lowest percentage and rate of germination and relative germination were found in two concentrations of the 0.076 and 0.1 mM of phenolic composition of E. crus-galli, so that no germination was observed in these treatments. In this study, mitosis division was normal in control samples, so that the rice plant included 12 chromosomes in the metaphase stage. Also the chromosomes were normal in the telophase stage and chromosomal abnormalities were not observed in meristem cells of radicle tip of the control. The lowest value of mitosis indices and the number of dividing cells were related to the concentration of 0.048 mM wuth 30.19 and 385 cells, respectively. In the present study, chromosomal abnormalities in the stages of metaphase, anaphase and telophase were increased with increasing concentration of phenolic composition, and were 28.85 and 16.95% in 0.048 mM concentration of phenolic composition, respectively. The most chromosomal abnormalities were of sticky and laggard type, which were related to the concentration of 0.048 mM of phenolic composition with 39.83 and 32.25%, respectively. The highest number of chromosomal bridges and clumping were obtained in 0.024 mM of phenolic composition with about 19.27 and 29.83%, respectively.
Conclusion: In this study, phenolic composition obtained from the methanol extract of E. crus-galli had asignificant inhibitory effect on germination traits and mitosis division in root tip cells of rice. Thus, the amount of E. crus-galli residues in the field should be considered in direct and indirect cultivation of rice.
Highlights:
1-Difference in impact of the phenolic composition obtained from the methanol extract of Echinochola crus-galli on germination and reduced cytogenetic behavior of rice is related to their threshold concentration.
2- It is advised to cultivate varieties of rice resistant to the remnants of harmful compounds of E. crus-galli as direct cultivation or under nursery condition.
Hamed Zamani, Hamidreza Mobasser, Aidin Hamidi, Alireza Daneshmand,
Volume 7, Issue 2 (3-2021)
Volume 7, Issue 2 (3-2021)
Abstract
Extended Abstract
Introduction: Seed is the fundamental input of crop production and tobacco is cultivated as transplanting and its transplant produced as float system. Therefore, seed germination and produced seedling health and diseases and pests management have high importance. So, evaluation of seeds dressing effect on germination and important pests and diseases management in the nursery for healthy transplantable seedling production is important. The study aims to investigate the effect of disinfectant of K326 tobacco seed on germination and percentage of transmissible transplants and management of contamination of sciaridae fly, aphid, and collar rot in a float system tray.
Material and method: This study was conducted as a completely randomized design in 3 replications at Tirtash Research and Education Center in 2014. seeds dressed by pelleting apparatus disinfected with Metalaxyl (Ridomil) and Thiophanate–methyl (TopsinM) fungicides and Imidacloprid (Gaucho), Thiamethoxam (Confidor) and Thiodicarb (Larvin) insecticide and seeds heating by 60ºC temperature warm air during 1 hour, seeds treatment by 50ºC heat water for 10 minutes and treatment by 0.5 percent concentration sodium hypochlorite for 4 minutes. Then normal seedlings percent by standard germination test, seedling emergence percent in float system, transplantable seedling of float system and infected to Sciarid fly, aphid and stem rot seedlings determined.
Results: Results showed that K326 Tobacco Seeds Disinfected by 2.5 g/kg metallaxyl + 2.5 g/kg thiophane-methyl (70% wettable powder) + 10 g/kg imidacloprid + 6 cm3/kg Thiodicarb had the highest percentage of normal seedlings, percentage of seedling emergence in the float system tray and percentage of removable transplants and the least seedling contaminated with sciaridae, aphid and collar rot.
Conclusion: Results of this study showed that all seed disinfection treatments improved seed germination, seedling emergence percentage, and removable seedlings in the float system tray as well as infected seedlings compared to control decreased collar rot, sciaridae fly, and aphids. Also, the mentioned traits were superior to the non-chemical disinfectant treatments in seed disinfection treatments with the studied fungicides and insecticides.
Highlights:
1- The effects of chemical disinfectant treatments (different insecticides and fungicides permitted and common) as coatings on seed germination and percentage of tobacco seedling emergence were evaluated and compared.
ed The effect of non-chemical disinfectant treatments on seed germination and percentage of tobacco seedling emergence and management of pests and diseases seedbed were evaluated and compared.
Introduction: Seed is the fundamental input of crop production and tobacco is cultivated as transplanting and its transplant produced as float system. Therefore, seed germination and produced seedling health and diseases and pests management have high importance. So, evaluation of seeds dressing effect on germination and important pests and diseases management in the nursery for healthy transplantable seedling production is important. The study aims to investigate the effect of disinfectant of K326 tobacco seed on germination and percentage of transmissible transplants and management of contamination of sciaridae fly, aphid, and collar rot in a float system tray.
Material and method: This study was conducted as a completely randomized design in 3 replications at Tirtash Research and Education Center in 2014. seeds dressed by pelleting apparatus disinfected with Metalaxyl (Ridomil) and Thiophanate–methyl (TopsinM) fungicides and Imidacloprid (Gaucho), Thiamethoxam (Confidor) and Thiodicarb (Larvin) insecticide and seeds heating by 60ºC temperature warm air during 1 hour, seeds treatment by 50ºC heat water for 10 minutes and treatment by 0.5 percent concentration sodium hypochlorite for 4 minutes. Then normal seedlings percent by standard germination test, seedling emergence percent in float system, transplantable seedling of float system and infected to Sciarid fly, aphid and stem rot seedlings determined.
Results: Results showed that K326 Tobacco Seeds Disinfected by 2.5 g/kg metallaxyl + 2.5 g/kg thiophane-methyl (70% wettable powder) + 10 g/kg imidacloprid + 6 cm3/kg Thiodicarb had the highest percentage of normal seedlings, percentage of seedling emergence in the float system tray and percentage of removable transplants and the least seedling contaminated with sciaridae, aphid and collar rot.
Conclusion: Results of this study showed that all seed disinfection treatments improved seed germination, seedling emergence percentage, and removable seedlings in the float system tray as well as infected seedlings compared to control decreased collar rot, sciaridae fly, and aphids. Also, the mentioned traits were superior to the non-chemical disinfectant treatments in seed disinfection treatments with the studied fungicides and insecticides.
Highlights:
1- The effects of chemical disinfectant treatments (different insecticides and fungicides permitted and common) as coatings on seed germination and percentage of tobacco seedling emergence were evaluated and compared.
ed The effect of non-chemical disinfectant treatments on seed germination and percentage of tobacco seedling emergence and management of pests and diseases seedbed were evaluated and compared.
Amin Haghighi, Yazdan Izady, Miad Haji Mahmoudi, Seyed Amir Moosavi,
Volume 7, Issue 2 (3-2021)
Volume 7, Issue 2 (3-2021)
Abstract
Extended Abstract
Introduction: Seed germination and seedling emergence depend on the genetics of plant species and are also influenced by environmental factors. Genetics and nutritional status of the maternal plant, maturity stage at a time of harvest, and environmental factors such as temperature, salinity, drought, and soil fertility influence seed germination. Seed vigor as the main parameter of seed quality decreases due to accelerated aging and storage. The objective of this study was to evaluate the response of accelerated aged Chia seed to different levels of salinity stress.
Material and Methods: Two-way factorial experiment with experimental factors, including five levels of seed accelerated aging durations (0, 24, 48, 72, 96 h) and six levels of salinity stress (0, 50, 100, 150, 200, and 250 mM) was arranged based on a complete randomized block design with three replications. The experiment was conducted at seed technology laboratory Khuzestan Agricultural Sciences and Natural Resources, University of Khuzestan, in 2019.
Results: Results of analysis of variance revealed that the effect of seed accelerating aging, salinity stress, and interaction effects of both factors on all measured germination traits were significant (p<0.01). The best pattern of seed germination was evaluated using three-parameter sigmoid models (logistic, Gompertz, and sigmoidal) and two polynomial models (quadratic and cubic), then the performance of all models was compared using (R2adj), root square of the mean (RMSE) and corrected Akaike index (AICc). Results showed that at accelerated aging duration, models' performance to describe Chia seed germination response varied at different levels of salinity stress. At no aging and 72h of accelerated aging treatments, the sigmoidal model exhibited the best fit on final seed germination, whereas for the other levels of accelerated aging, Gompertz exhibited the best fit. Based on the output of the sigmoidal model, for no aging and 72 hours of accelerated aging, 50% of seed germination was declined at 171.7 and 76.9 mM, respectively, and based on the results of the Gompertz model, after 24 and 48 h of accelerated aging, seed germination declined to 50% at 163.8 and 129.6 mM. Results obtained from fitting polynomial models on seed germination showed that the cubic model provides reasonable descriptions for studied traits such as seed vigor.
Conclusion: Chia seed germination was sensitive to salinity and accelerated aging treatments. At no aging condition, Chia seeds tolerate salinity stress up to 200 mM and were able to germinate. By increasing aging durations, seed germination declined dramatically at all salinity levels and after 96 hours of aging, there was no seed germination at 150 mM.
Highlights:
1- The best nonlinear model to study accelerated Chia seed response to salinity stress was selected using the model selection criterion.
2- Chia seed germination threshold to salinity stress was determined for not- aged and aged seeds.
Introduction: Seed germination and seedling emergence depend on the genetics of plant species and are also influenced by environmental factors. Genetics and nutritional status of the maternal plant, maturity stage at a time of harvest, and environmental factors such as temperature, salinity, drought, and soil fertility influence seed germination. Seed vigor as the main parameter of seed quality decreases due to accelerated aging and storage. The objective of this study was to evaluate the response of accelerated aged Chia seed to different levels of salinity stress.
Material and Methods: Two-way factorial experiment with experimental factors, including five levels of seed accelerated aging durations (0, 24, 48, 72, 96 h) and six levels of salinity stress (0, 50, 100, 150, 200, and 250 mM) was arranged based on a complete randomized block design with three replications. The experiment was conducted at seed technology laboratory Khuzestan Agricultural Sciences and Natural Resources, University of Khuzestan, in 2019.
Results: Results of analysis of variance revealed that the effect of seed accelerating aging, salinity stress, and interaction effects of both factors on all measured germination traits were significant (p<0.01). The best pattern of seed germination was evaluated using three-parameter sigmoid models (logistic, Gompertz, and sigmoidal) and two polynomial models (quadratic and cubic), then the performance of all models was compared using (R2adj), root square of the mean (RMSE) and corrected Akaike index (AICc). Results showed that at accelerated aging duration, models' performance to describe Chia seed germination response varied at different levels of salinity stress. At no aging and 72h of accelerated aging treatments, the sigmoidal model exhibited the best fit on final seed germination, whereas for the other levels of accelerated aging, Gompertz exhibited the best fit. Based on the output of the sigmoidal model, for no aging and 72 hours of accelerated aging, 50% of seed germination was declined at 171.7 and 76.9 mM, respectively, and based on the results of the Gompertz model, after 24 and 48 h of accelerated aging, seed germination declined to 50% at 163.8 and 129.6 mM. Results obtained from fitting polynomial models on seed germination showed that the cubic model provides reasonable descriptions for studied traits such as seed vigor.
Conclusion: Chia seed germination was sensitive to salinity and accelerated aging treatments. At no aging condition, Chia seeds tolerate salinity stress up to 200 mM and were able to germinate. By increasing aging durations, seed germination declined dramatically at all salinity levels and after 96 hours of aging, there was no seed germination at 150 mM.
Highlights:
1- The best nonlinear model to study accelerated Chia seed response to salinity stress was selected using the model selection criterion.
2- Chia seed germination threshold to salinity stress was determined for not- aged and aged seeds.
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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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