نشریه علوم و فناوری بذر ایران
سال دهم شماره 2 (پیاپی 22، تابستان 1400)

In order to knowledge the dormancy and seed germination of field dodder in response to environmental factors (sulfuric acid (physical dormancy), light, temperature, salinity and drought stress) four separate experiments were conducted at agricultural scientists and natural recourses university of Khuzestan. Treatments of sulfuric acid (96%) immersion (0, 10, 20, 30, 60, 90 and 120 m exposure to sulfuric acid), temperature (5, 10, 15, 20, 25, 30, 35, 40, 45°C). Light (light/dark and darkness), salinity (0, 50, 100, 150, 200, 250, 300, 350, 400 and 400 mM) and drought stress (0, -0.2,-0.4, -0.6, -0.8, -1 and -1.2 MPa) were considered. Seed immersion for 30 m increased germination up to 100% while by increasing of seed immersion in sulfuric acid to 120 minutes, germination decreased to 60%. Seed germination were at 10°C (53%), 20 (88%), 25 (100%), 30 (100%), 35 (100%) and 40°C (42%). Germination of field dodder wasn’t dependent on light. The salinity required to 50% inhibition for traits germination percentage, germination index and germination rate were predicted 154.89, 139.71 and 119.11mM respectively. From the results of drought stress indicated that for 50% inhibition of germination percentage, germination index and germination rate (logistic equation) were predicted -0.57, -0.43 and 0.52 MPa respectively.

This research was carried out to evaluate the storage of wheat seed which produced under different conditions of water deficit and application of chemical nitrogen and biological fertilizers as the first factor was water deficit in milky stage, drought stress at dough stage and without stress (control), and nitrogen fertilizer resources in Urea fertilizer 100%, 75%, 50% and 25% of plant requirement with nitroxin and nitragin. The second factor was storage conditions in 7 and 14% seed moisture within 20 and 4 °C storage, and the third factor was the storage period at 50, 100, 150 and 200 days. The results showed that the content of soluble protein and seed vigor index in seeds that received nitroxin and nitragin fertilizers with 25% urea, by increasing the water deficit, from 1.208 to 0.581 mg/g fresh weight and from 1.945 to 0.376 increased relative to 100% urea, respectively. The amount of catalase activity in seeds with drought stress and biofertilizer was higher and its activity increased at higher storage temperatures. In general, if the irrigation of the maternal plant is discontinued at the seed dough stage and the plant is fed with integrated of chemical and biological fertilizers, then the seed produced had more storage capability.

In this study, the effect of ultrasound on the germination and vigor index of Iranian black cumin (Bunium persicum Boiss.), was studied. Response surface methodologhy and central composite design were used ti analyze the data and optimize the experiment. A factorial experiment based on completely randomized design was conducted. Experimental factors included time of ultrasound treatment (5, 7 and 9 minutes), ultrasonic power (130, 180 and 230 watts) and sonication temperatures (10, 20 and 30 °C) as well as control and germination percentage and seed vigor index were measured. The highest germination percentage and seed vigor index were determined by Response Surface Methodology (RSM). The results indicated significant effect of time and ultrasound power on studied traits, but temperature had no significant effect on them. The highest germination percentage (61%) and seed vigor index (800) were observed at 180 W and 7 min duration time and 20 °C. The lowest germination percentage (24.5%) and seed vigor index (462) were observed in 230 W ultrasound power, 9 min duration time and 20 °C. Also, the optimization results showed that the best points for power, time and temperature for achieving the highest values of germination percentage and seed vigor index were 175.47 W, 6.37 min and 19.36 °C, respectively and the output values (germination and seed vigor index) were obtained the this points 63.02% and 808.39 respectively. Finally it seems that the increasing or decreasing time and power of ultrasonication in a certain range decreases the seed germination percentage and vigor index.

AbstractObjective of this research was identification and determination of the most suitable treatments to improve seed germination characteristics of Thyme medicinal plant. In order to evaluate different priming treatments on seed germination characteristics of Thyme, an experiment was conducted in a completely randomized design with four replications which treatments were: without priming (control), Gibberellic acid (100, 200 and 300 ppm), Cytokinin (200 and 400 ppm), thiourea (1000, 2000 and 3000 ppm), potassium nitrate (10, 20, 100, 200, 300 and 400 ppm), phosphorus (10, 20, 30 ppm), manganese sulfate (2, 4 and 6 ppm). Germination characteristics such as shoot and radicle length, germination percentage, seed vigor, mean germination time and germination rate were evaluated. The results showed significant effects of seed priming treatments on shoot and radicle length, germination percentage, seed vigor and mean germination time at 1% probability level and germination rate at 5% probability level. Among the treatments, gibberellic acid treatments (100 ppm) and potassium nitrate (200 ppm), thiourea (2000 ppm) and manganese sulfate (4 ppm) presented high positive impacts on germination. Cytokinin treatments also significantly decreased many germination characteristics. It seems that potassium nitrate and gibberellic acid treatments compared with other treatments are more effective to improve all thyme germination characteristics. 

This study evaluated different methods of improving seed germination in tamarind (Tamarindus indica L.). The experiment was laid out in a completely randomized design and each treatment was replicated four times. Treatments were consisting of distilled water for 24 h at ambient temperature, hot water 80 Ċ for 5 min, potassium nitrate (KNO3) at 1 and 2% for 24 h, sulphuric acid (98% H2SO4) for 5 min, sulphuric acid (50% H2SO4) for 10 min and control (seeds were not treated). Results showed that the greatest percentage and speed germination and was observed in treatment of sulphuric acid (98% H2SO4) for 5 min. The lowest Mean time to germination was obtained in sulphuric acid (98% H2SO4) for 5 min followed by potassium nitrate at 1% . Maximum seed vigour index was observed in sulphuric acid (98% H2SO4) for 5 min that had no had no significant difference with sulphuric acid (50% H2SO4) for 10 min and potassium nitrate (1 and 2%) for 24h. pre-treatment of distilled water and hot water were not effective in improving seed germination of tamarind. The highest number leaf, length of shoot and root, fresh and dry weight of stem and root was observed in potassium nitrate at 1% for 24h followed by potassium nitrate at 2%. Therefore, the results showed that pre-treatment of seed with potassium nitrate 1% for 24h is effective way to improve seed germination and early growth of tamarind.

With the aim of investigation of Humic and biological fertilizer sources together with nitrogen fertilizer on corm production on Torbat Heydarieh landrace, an experiment was conducted in research farm of University of Torbat Heydarieh in 2015-2016. The experiment consisted 18 treatments in which main factor was three levels of nitrogen fertilizer (0, 25, 50 kg/ha as urea) and sub factor was application of Biumic (micronutrients and acid humic), Super humic, Superhumic+Biumic, Humiful (acid humic), Nitrokara (nitrogen, phosphorus-soluble bacteria) and control. The experiment performed as split plot layout based on randomized complete block design with three replications. Results demonstrated that application of nitrogen had the significant effect on fresh weight and fresh yield of replacement corms. In 25 kg nitrogen treatment the fresh weight and fresh yield of replacement corms increased 5.6 and 8.2 percent in compared to control, respectively. In Super humic+Biumic treatment the fresh and dry weight of replacement corms increased 61.5 and 60.2 percent in compared to control, respectively. All of resource treatments significantly enhanced number of replacement corm. Overall, it seems that nitrogen fertilizer using had not considerable impact on corm traits, but employing of Humic and biological fertilizer could be very important on saffron corm production.

Environmental stress is the main effect reducing plant growth and development especially in germination stage. The aim of this project was to determine the threshold for salt stress tolerance in germination stageand mature plant in barley (Hordeum vulgare L.) genotypes and evaluate the relation between indices. First, the LD50 test was conducted for salt stress tolerance using NaCl, then probit analyze was done. The reaction of seven selected genotypes from barley and three cultivars were assessed in four levels of salinity and drought stress. Factorial experiment was conducted in a randomized complete block design with four replications. Based on probit analysis, the LD50 for salinity stress was 18 ds/m. Salt stress germination experiment included control, 9, 18 and 27 ds/m levels. Principal component analysis showed that at two levels of moderate and moderate stress in germination experiments (9 and 18 dS / m) that the salinity concentration was close to field conditions, in vitro tolerance indices and The field showed a close relationship. This relationship was not observed at severe stress levels (27 ds/m). Overall, the results showed that genotypes TN4807, KC70173, TN6141 and Nosrat cultivar had higher tolerance to germination conditions (9 and 18 ds/m) and field conditions.

Guar (Cyamopsis tetragonoloba L.), is an annual plant of the legume family. The gum of this plant, which is actually extracted from the seed endosperm, is used in various industries. Germination and seedling growth indices are among the most important indicators for selecting salinity tolerant genotypes. In this study, the effects of 4 salinity levels (such as: 0, 80, 150 and 220 mM) on germination characteristics and preliminary seedling growth (including percentage and rate of germination, seed vigor, etc.) of ten genotypes and guar seed selection were investigated. The results showed that salinity treatment, genotype and interactions of genotype × salinity on seed vigor index, root length, shoot length, seedling length were significant at 1% probability level. Mean comparisons showed showed that RGC-1008 had the highest percentage and germination rate and Saravan had the lowest percentage and germination rate. Mean comparison of salinity levels showed that the control had the highest (2.23cm) and the 150 mM treatment has the lowest shoot length (1.47cm). RGC-1038 and Bampour with 395.3 and 414.73 showed the highest seed vigor respectively, and Saravan with 68.32 showed the lowest seed vigor. In general, RGC-1008 can be a suitable candidate to cultivate in salinity stress after affecting other agronomic treatments.

In order to investigate the effect of hydropriming and osmopriming on the characteristics of experimental rice seedlings, the treatment was performed in a completely randomized design in three replications.Treatments included two rice cultivars (Tarom and Shiroudi) and priming at five levels including calcium chloride and potassium chloride priming (Ψs -1.25 MPa), ascorbate acid (10 mg l-1), hydropriming (for 48 hours) and control (no priming). In this study, seedling characteristics were measured. Interaction of cultivar and priming showed that the highest germination percentage was observed in the range of 97-100% in Shiroudi and Tarom cultivars primed with calcium chloride and potassium chloride. The lowest germination percentage (85.33% and 77.33%, respectively) was obtained under control in Shiroudi and Tarom cultivars, respectively. The highest germination rate was obtained in priming with calcium chloride and potassium chloride, which increased the germination rate by 52 and 54%, respectively. The effect of cultivar and priming on root and shoot length as well as root and shoot dry weight were significant at 1% probability level. also, root and shoot length were 5.97 and 5.4 cm in Shiroudi and 4.01 and 4.59 cm in Tarom, respectively. The results showed that priming with calcium chloride, potassium chloride, ascorbic acid and water increased seedling length vigor indices 69, 64, 13 and 32% in Shiroudi and 91, 70, 47 and 43% in Tarom, respectively compared to control. Also, priming with calcium chloride, potassium chloride, ascorbic acid and water increased seedling weight vigor indices by 110, 95, 50 and 47%, respectively.

The phenomenon of seed dormancy in weeds not only lead to management difficulties over time but also can disrupt the biological, morphological and ecological studies carried out on these species. This study was conducted to investigate the effect of ultrasound on seed dormancy breaking of Datura stramonium and Convolvulus arvensis in laboratory conditions. Two separate experiments were conducted as a completely randomized design with four replications for each species. The ultrasonic waves were applied at five powers including 0, 80, 150, 250 and 350 watts for four and eight minutes, where the applied ultrasonic frequency was 20 kHz and the temperature of water was remained constant at 25°C. In addition to the ultrasound treatments, the common dormancy-breaking treatments including chilling (natural chilling, moist chilling and dry chilling) and mechanical scarification were applied on D. stramonium and C. arvensis, respectively. All sonication treatments decreased accumulated maximum germination (Gmax) of both weed species. Also, the ultrasound treatments increased time to 50% of maximum germination (G50) of D. stramonium. The ultrasonic effect on G50 of C. arvensis was depended on ultrasonic power, where at low ultrasound powers the G50 of D. stramonium was similar to untreated seeds, while it was decreased at high ultrasound powers. Accordingly, ultrasound was not a suitable method to break seed dormancy of D. stramonium and C. arvensis. As the best treatments, the natural chilling and mechanical scarification increased Gmax of D. stramonium and C. arvensis up to 49% and 38%, respectively.