Showing 137 results for Germin
Khadijeh Badpa, Mohsen Movahhedi Dehnavi, Alireza Yadavi,
Volume 2, Issue 2 (2-2016)
Abstract
To evaluate the interaction of Cd and SA on seed germination of Safflower (Carthamus tinctorius L. cv. Soffe), this experiment was carried out as a factorial based on CRD with four replications in 2012, in Yasouj University seed lab. Factors included of four levels of seed priming with SA (0, 0.3, 0.6, and 0.9 mM) and eight levels of cadmium nitrate (0, 5, 10, 15, 20, 25, 30 and 35 mM). In all Cd treatments, SA 0.9 mM had maximum germination percentage (84% in 0 mM Cd) and rate (6.58 seed day-1 in 5 mM Cd), radical length (4.21 cm in 0 mM Cd) and stem (3.29 cm in 0 mM Cd), radical dry mater (2.25 mg in 0 mM Cd), shoot dry matter (0.94 mg in 0 mM Cd) and seed vigor index (6.30 in 0 mM Cd). Generally, seed priming with SA decreased the impact of Cd on seed germination and SA 0.9 mM was the best treatment.
Rrahele Aahmadpour, Nezam Armand, Saeed Reza Hossinzadeh,
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.
Zeinab Alipoor, Sohrab Mahmodi,
Volume 2, Issue 2 (2-2016)
Abstract
In order to determinate the cardinal temperatures and investigate the effect of temperature on seed germination and seedling growth of Securigera securidaca, a study was conducted in a completely randomized design with 8 temperature treatments (5, 10, 15, 20, 25, 30, 35 and 40oC) and four replications in research laboratory of faculty of agriculture at the Birjand University in 2013. A two-segmented linear regression model was fitted between germination rate and temperatures to determine cardinal temperatures for germination. Cardinal (minimum, optimum and maximum) temperatures of germination were determined as -1, 22.5 and 40.2oC respectively. Maximum rate and percentage of germination obtained in the range of 20-25oC. Maximum of radicle length and dry weight, maximum of caulicle length and dry weight and maximum of vigor seedling were obtained in 20oC,10-20oC and 5-30oC respectively. Maximum and minimum germination uniformity (GU) was obtained in 25 and 5oC.
Somayeh Rastegar, Mostafa Ahmadzadeh, Hojat Piroozy,
Volume 2, Issue 2 (2-2016)
Abstract
Allelopathic compounds display an important role in biodiversity, stability and ability of ecosystem production. An experiment was conducted to investigate the allelopathic effect of six species, Cordia myxa, Melia indica, Delonix regai, Terminalia catappa, Eucalyptus camadulensis, Ficus religiosa on germination and seedling growth of Calendula officinalis. An experiment was performed in a completely randomized design with three replications in the lab of the horticultural Hormozgan university during 2014. A completely randomized design with three replications was carried out in the laboratory. Results indicated that the percentage of germination, seed germination rate, plumule and radicle length, and seed vigor of Calendula officinalis significantly reduced under aqueous extract of all species. But, there was no significant difference between dry weights. Delonix regia extract ceased the seed germinates in both concentrations. After that Melia indica extract had a highly significant inhibitory effect on seed germination, plumule and radicle length when compared to control. The results of this experiment also showed that the inhibitory effects of Cordia myxa and Terminalia catappa were lower in compared to other species. Between two concentrations, 100% concentration has a more inhibitory effect. The results of the present study revealed that inhibition of germination and growth parameters of Calendula officinalis showed variation according to the different plants. Cultivation of Calendula officinalis with Melia indica, Delonix regia species don’t suggest in the landscape.
Hamid Sharifi, Morteza Goldani,
Volume 2, Issue 2 (2-2016)
Abstract
Seed coat color as a perfect and simple index is effective in water absorption, seed dormancy and germination. The mustard plant produces seeds with different coat color. So, in order to investigate the effect of seed coat color on germination rate, the percentage of germination and dormancy of Mustard (Sinapis arvensis L.) seeds an experiment was carried out based on a completely randomized design with four replications. Treatments were included two types of seed coat color (brown and black) and dormancy breaking treatments (Control, Potassium nitrate 0.2%, GA3 250, GA3 500 ppm and one, two and three weeks prechilling). The results showed that the differences between germination indices traits in brown and black seeds were significant. So that, the germination rate and germination percent in black seed were greater than brown seeds, but the duration of dormancy in brown seeds was greater than black seed. One week prechilling treatment had the most effect on breaking dormancy. So that germination percentage and germination rate for black seed was 75% and 0.54 respectively and these amounts for brown seeds were 58% and 0/43 respectively. Potassium nitrate and GA3 (250 and 500 ppm) reduced germination rate and germination percent in both types of seeds. In addition, water absorption percent in brown seeds was more than black seeds. The final results showed that heteromorphic seeds of Mustard have variation in duration of dormancy, germination and water absorption percent.
Mina Arast, Ali Tavili, Saied Shojaei,
Volume 2, Issue 2 (2-2016)
Abstract
A vast area of Iran is covered by sand dunes. Biological control is an appropriate method for sand dune fixation. So, it is essential to recognize characteristics of psammophyte plant species and introducing suitable species for sand dunes. Ammodendron persicum is one of the important and compatible species in desert ecosystems. The current research was carried out to investigate the effect of different treatments on seed dormancy breaking and germination stimulation of Ammodendron persicum in order to determine the most effective treatment in enhancing of germination and primary growth of seedlings. The experiment was done in a completely Randomized Design. Our experimental design was included10 random attendance namely: soaking of Ammodendron persicum seeds in gibberellic acid (300ppm) for 48 hr, seed scratching scarification with acid in two interval times of 20&30 min, incorporation of later with sand paper scratching scarification, seed scratching with gibberellic acid (300ppm) and time period of 48hr Ammodendron persicum seed sand papering combined with gibberellic acid soaking, wetting Ammodendron persicum seeds with high temperature water (80°C) for 5&10 min then scratching them by sand paper and also using distillated water as control treatment evidence. Experimental results showed, 30 minutes sulfuric acid soaking combined with sand papering can increase germination to 90% of the laboratory. In addition, seed scratching with gibberellic acid (300ppm) and time period of 48hr Ammodendron persicum seed sand papering combined, wetting Ammodendron persicum seeds with high-temperature water (80°C) for 5&10 min, the percentage of germination, respectively, 45/15, 45/8, 17/10 and 68/28 respectively. Moreover, 30min high-density sulfuric acid caring improves Ammodendron persicum, seed vigor, the power of greenhouse and lab samples to 450 and 510 respectively. Finally, authors reported scratching and acid soaking combination as an efficient, caring method in this research.
Hossein Sadeghi, Hossein Heidari Sharifabad, Aidin Hamidi, Ghorban Nourmohammadi, Hamid Madani,
Volume 2, Issue 2 (2-2016)
Abstract
In order to evaluate the effect of seed moisture content at harvesting time and drying temperature on soybean seed germination characteristics, an experiment was conducted as factorial (2×3×2) based on Randomized Complete Block Design with three replications in Karaj and Moghan areas. The first factor was cultivar with two levels (Williams and L17), the second factor was seed moisture content with three levels (15, 20 and 25%) and the third factor was drying temperature with two levels (30 and 45 °C). Results show that the germination percentage of producing seeds in Karaj (81.3%) were higher than Moghan area (77.4%). The difference between the germination percentage of dried seeds at 30 and 45◦C with initial seed moisture content of 15% was about 5.5%, while this difference for seeds with 25% initial moisture content was about 18.5%. There was no significant difference between seedling vigor index of seeds with 15% moisture content of two cultivars that have been produced in Karaj, but at 20% moisture content, the seedling vigor index in Williams cultivar (139.7) was higher than L17 cultivar (107.3). The highest (51.42 µsm cm-1 g-1) electrical conductivity of seed leakage soluble was obtained from the L17 cultivar with 25% moisture content and 45◦C and the lowest (28.46 42 µsm cm-1 g-1) rate of it was observed in Williams cultivar with 20% moisture content and 30◦C. According to these results, we must harvest and dry soybean seeds at 30◦C when its moisture content reached under 20%.
Bita Oskouei, Eslam Majidi-Hervan, Aidin Hamidi, Foad Moradi, Ali Moghaddam,
Volume 2, Issue 2 (2-2016)
Abstract
This experiment was conducted as a factorial experiment based on a completely randomized design with three replications at two locations: Agricultural and natural resource center of Ardebil province (Moghan) and seed and plant certification and registration institute of Karaj in 2013. The treatments included: planting date in three levels (10-May, 25-May and 9-Jun), seed moisture content at harvest time in four levels (30%, 25, 20 and 15) and seed size in three levels (flat, round and medium). The measured traits were a standard germination test, mean time of germination, seedling weight and length vigor index, germination percent in radical emergence test and germination percent in cold test. The results illustrated that delayed planting caused reduction of seed quality and this reduction was more obvious in delayed harvest (15%), also the reduction rate in round seeds was more than flattered and medium seeds. The minimum percentage of germination and vigor were seen in round seeds of third planting date and moisture harvest by 15%. So it is recommended for corn seed production to sow the seeds before the last week of May and when seed moisture content reached 30 percent, cob harvesting should be started and the harvest not is delayed.
En Mehrazar Ashraf, Kamal Sadat Asilan, Farid Golzardi, Shahram Nazari, Ramin Salehi,
Volume 2, Issue 2 (2-2016)
Abstract
Three separate experiments conducted to survey the response of two populations of common purslane weed collected from Karaj and Ahvaz on germination and early growth. The first experiment was based on 4 levels of flooding, including 1, 2, 4, 8 days plus non-flooding treatment as a control. Second experiment addressed the impact of various acidity levels, such as 4, 5, 6, 7, 8, 9, 10 and finally third experiment considered the influence of high temperatures of 60, 80, 100, 120, 140, 160, 180, 200, 220 centigrade on germination rate, germination percentage, radicle length and plumule length as well as fresh weight of the aforementioned population of common purslane (Karaj and Ahvaz). Analysis of variance revealed that in both weed populations, all germination indices were impressed by flooding periods, acidity levels and high temperatures. Extending the flooding periods resulted in reducing all measured parameters in both weed populations, so the growth of common people was completely inhibited less than 8 consecutive days of flooding. Germination rate and percentage improved gradually by increasing the acidity value from 4 up to 7. An adverse relation was observed between the measured parameters and temperature variations in both Karaj and Ahvaz weed population. Germination rate and percentage, radicle and plumule length, as well as the fresh weight of seedling, decreased significantly in response to increasing the oven temperature. Overall, it can be concluded that boosting our knowledge about both ecology and biology aspects of the common person can pave the way for introducing new ways in line with expanding long-term strategies, improving management systems and predicting the mode of germination and growth of this important weed.
Fatemeh Aliyari, Ali Soltani, Mehrdad Zarafshar,
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.
Yaghoub Behzadi, Amin Salehi, Hamidreza Balouchi, Fahimeh Khaledi,
Volume 2, Issue 2 (2-2016)
Abstract
In recent years the use of allopathic effects on weed management seems to have attracted many professionals. In order to investigate the effect of aqueous extracts of Yarrow (Achilla wilhelmsii L.) and Habek mint (Mentha longifolia (L.) Huds) medicinal plant on germination indices of plantain, two experiments were conducted in completely randomized design with three replications in 2014 in the laboratory of seed technology of Yasouj university. Treatments consisted of 0, 25, 50, 75 and 100% concentrations of aqueous extract of Yarrow and Habek mint aerial parts. The results showed that the extract of Yarrow and Habek mint aerial parts on germination percentage, root and shoot length, root and shoot fresh and dry weight and seed vigor was significant. The maximum percentage and rate of germination have belonged to the control treatment (distilled water) and by decreasing the aqueous extract concentrations of each plant, the percentage and rate of germination increased. The minimum percentage and rate of germination have belonged to 100% concentration of aqueous extract that had no significant difference by 75% concentration. Finally, these results showed allelopathic effects of aqueous extract aerial parts of Yarrow and Habek mint, as a bio-herbicide on growth and germination of plantain.
Maryam Janalizadeh, Ahmad Nezami, Hamidreza Khazaie, Hassan Feizi, Morteza Goldani,
Volume 3, Issue 1 (8-2016)
Abstract
Priming of seeds by magnetic fields (magneto priming) is proposed as an ecological, useful and low-priced method for improvement of seed germination and plant emergence. In order to evaluate the germination behavior of sesame seeds affected by magnetic fields, an experiment was conducted as a completely randomized design with 22 treatments (non-exposure to magnetic fields (control) and 21 magneto priming treatments) with three replications at the college of agriculture, the Ferdowsi University of Mashhad in 2014. the seed of sesame put into a plastic bag bulky and was treated with different intensity of magnetic fields (25, 50, 75 and 100 mT) for several times (10, 20, 30, 60 and 120 minutes). For assessment of germination traits of sesame under constant magnetic field conditions, magnetic tapes with three mT strength were used in each Petri dish throughout the experiment. Results showed that magnetic fields had no significant effects on final germination percentage and mean germination time and all magnetic treatments except for 75 mT at 60 minutes indicated reducing effects on germination percentage in comparison to control. Priming of seeds with magnetic fields in 50 mT strength for 20 minutes led to the increment of germination rate compared to control treatment but all levels of 100mT treatment caused a reduction in germination rate than control. The most radicle length, seedling length and seedling vigor length index belong to 75 mT at 60 minutes treatment and the most seedling dry weight and seedling vigor weight index related to 100 mT for 20 minutes treatment. Ranking of treatments showed that exposure of seeds for one hour in 75 mT and 10 minutes in 25 mT magnetic fields strength had the best outcomes.
Mohammad Bahmani, Sonia Yousefi, Davoud Kartolinezhad,
Volume 3, Issue 1 (8-2016)
Abstract
In this study, the effect of different doses of gamma radiation was investigated on seed germination factors of Caper species. Gamma irradiation was performed using a cobalt-60 radiation with the radiation speed of 0.018 Gray/second and five doses of gamma radiation (0, 20, 40, 60 and 100 Gray) in a completely randomized design with 4 replication. The results showed that gamma radiation significantly affects some of the seed germination factors. So that the 100 Gray treatment increased the germination percentage up to 43.2% as compared with other treatments. The average time of germination in seeds treated with gamma decreased 0.91 days rather than control. Length of the stem let in gamma treatments increased 62.3% rather than control; so that the fresh and dry weight of stem let at 100 Gray were respectively increased 171.4 and 27.3% in comparison with the control. The fresh and dry weight of rootlets were respectively increased 417.9% and 668% rather than the control one. Seed vigor at 100 Gray was 32.3% higher than the control. From among the different studied doses, 100 Gray showed the highest influence on the seed germination and physiology although the induced changes were in low amounts. This study revealed that gamma irradiation has not major influences on improving seed germination characteristics of Caper shrubs.
Shahram Nazari, Mohammad Ali Aboutalbian, Farid Golzardi,
Volume 3, Issue 1 (8-2016)
Abstract
Seed priming is a method which is a quite effective method for improving germination and seedling establishment. Two separate experiments were performed to determine the best hydro and osmopriming treatments effects on canola‘s seed germination. The experiments were performed in seed technology laboratory of Islamic Azad University, Karaj, Iran, 2014. The first experiment contained three canola varieties seeds hydropriming (Okapi, Zarfam and Talayeh) using tap water over time interval 0. 2, 6, 10, 14, 18, 20 and 24 hours. The second experiment included, tree canola cultivars in accompany with six concentrations of ZnS04 (0, 0.035, 0.1, 0.4, 1 and 4 gr.Lit-1) over priming time interval of 0, 6, 10 14 and 18 hours. Both experiments were conducted as a factorial experiment in the context of completely randomized design (CRD) with four replications. The results revealed that the maximum germination percentage across all cultivars e.g. Okapi (99%), Zarfam (95%) and Talayeh (80%) is achieved at 10 hours hydropriming interval. Also concerning to germination rate, the best performance was observed for Talayeh cultivar at 10 hydropriming hour’s interval. The most vigor longitudinal and vigor weighted indices (1050.55 and 4.56) were observed in the Okapi cultivar in the fourth hydropriming level. The interaction between the cultivars, the concentration of ZnS04 and osmopriming time was significant for all characters except for shoot dry weight and vigor weighted Index. The three-way interaction showed that the highest shoots dry weight (0.11, 0.057 and 0.055) and also vigor weighted index observed in Okapi, Zarfam and Talayeh cultivar in 0.035 concentration of ZnS04 (gr.lit-1) at the time was 10 hours, respectively. The results of this study showed that hydropriming and ZnS04 might improve the performance of rapeseed Cultivars seed.
Mohsen Azarnia, Abbas Biabani, Hamid Reza Eisvand, Ebrahim Gholamalipour Alamdari, Saeed Safikhani,
Volume 3, Issue 1 (8-2016)
Abstract
One of the important strategies for increasing germination speed and germination percentage, to produce high-quality seedling and plant optimal establishment is seed priming. In order to evaluate reactions of a lentil seed to priming duration and concentrations of the applied material as priming, a factorial experiment based on a completely randomized design with three replications was done in the agronomy laboratory of agriculture and Natural Resources College of Gonbad Kavous University in 2013. Factors included priming duration (4, 8 and 12 h) and various concentrations of the priming (hydro priming, hormonal priming by gibberellic acid and salicylic acid with the concentrations of 50, 100 and 150 ppm and non primed seeds). Results showed that the interaction effect of the concentrations and duration of the priming was significant on whole measured traits except the seed vigor index, germination percentage and seedling dry weight at 1% probability level. The lowest duration of germination (5, 10, 90 and 95%) obtained in the hydropriming treatment (2.72, 5.43 and 18.17 hour). The highest radicle fresh weight was observed in hydropriming treatment in three studied durations priming. In this study; the highest rate of germination obtained from GA50ppm during 12 hours. GA50ppm increased Germination percentage (98%). The greatest radicle length, shoot length and relative growth rate was obtained in the treatment of the gibberellic acid 100 ppm during 8 hours. All the average, gibberellic acid 100 ppm in 8h had an additive effect on the most of the measured traits of the lentil seed. Therefore, it can be introduced as the best mixture treatment.
Abdoljalil Yanegh, Mohammad Khajehosseini,
Volume 3, Issue 1 (8-2016)
Abstract
The need to identifying seeds with low vigor and poor emergence led to introduce of various seed vigor tests. The purpose of this experiment was to assess the ability of controlled deterioration test for evaluation of seed vigor and prediction of oilseed rape seed lots emergence in the field. Samples of 19 seed lots were obtained from nineteen farmers of Razavi and Northern Khorasan Provinces, which have been cultivated during 2009-2010 growth season, set to physiological germination test before and after controlled deterioration (CD). The estimating of seedling emergence percentage of each seed lot in the field calculated 30 days after sowing. The correlation between laboratory results before and after CD of seeds and field emergence showed that correlation of final germination, normal seedlings and mean germination time before CD with emergence in the field respectively with 0.072, 0.24 and 0.042 correlation coefficient, were not significant, but laboratory results after CD had significant correlation with emergence of seed lots in the field. As, final germination, normal seedlings and mean germination time respectively with 0.57, 0.51 and 0.49 correlation coefficient predict emergence percentage of seed lots in the field. The high correlation between laboratory results after controlled deteriorated test with the seedling emergence in the field indicated that the CD test is able to assess the field emergence of oilseed rape seed lots before sowing.
Sahar Mohammadiyan, Maryam Nasr Esfahani,
Volume 3, Issue 1 (8-2016)
Abstract
Efficient seed germination and rapid and uniform seedling emergence are important in commercial agriculture. Therefore, the use of strategies to improve germination and seedling establishment is necessary for increasing productivity. Hydropriming has been suggested as a simple pre-germination strategy to improve seed performance. In this study, the effects of different durations of hydropriming (10, 24, 48 and 72 hours) at different temperatures (10 and 25 ˚C) compared to unprimed seeds on the vigor and germination performance of five milk thistle accessions (Ahvaz, Sari, Esfahan, Dezfol and Gachsaran) were evaluated. An experiment was conducted as a factorial experiment based on a completely randomized design with three replications. Germination performance was evaluated by final germination percentage, mean daily germination, mean germination time, the coefficient of germination, Timson's index, time to reach 50% the final germination percentage, germination value, coefficient of uniformity of germination, length and dry weight of seedlings and vigor index. The results show that germination capacity, germination rate and seedling vigor indexes increase significantly in hydro primed seeds at a temperature of 10˚C, whereas a decrease in hydro primed seeds at a temperature of 25˚C. Our results also show that the efficacy of hydropriming on seedling emergence and vigor traits depends on the priming duration and temperature. Hydropriming at 10˚C indicated the most effective on germination indicators and seedling vigor when compared to unprimed seeds. In addition, the comparison of germination and growth indicators in different durations of hydropriming in five milk thistle accessions indicated that the best duration of hydropriming for Ahvaz and Gajsaran is 72h, for Sari and Dezfol is 48 and 72h and for Esfahan is 10 and 24h. Therefore, the effect of hydropriming on germination performance and seedling vigor depends on plant association and hydropriming time and therefore, the selection of the best condition for hydropriming will improve the seed germinability and vigor.
Marjan Diyanat, Seyyed Meisam Hosseini,
Volume 3, Issue 1 (8-2016)
Abstract
In order to study the responses of redstem filaree (Erodium cicutarium L.) seed germination to temperature levels, an experiment was carried out in a completely randomized design with four replications and twelve levels of temperature (0, 3, 5, 7, 10, 12, 15, 20, 25, 30, 35, 40 0C). Results showed that the effect of treatments on germination properties of redstem was significant, so the highest percentage of germination was achieved at 150C and reduced with increasing temperature and was totally inhibited at 40ºC. Based on a linear regression between germination rate and temperature, the cardinal temperatures: minimum (Tmin), optimum (To) and maximum (Tmax) were determined: 0, 15.20 and 37.18 ºC, respectively. A significant difference was not observed in plumule length at a range of 5-30°C that showed that it is less sensitive to temperature in comparison with root length. Highest wet-dry weight was achieved at 20 °C that was not different by 10, 12 and 20°C. Above results suggest that redstem failure could grow in a wide range of growing conditions, but prefers temperate zones. The results of this study are important to understanding thermal requirements and improvement of management strategies of redstem filaree.
Almas Nemati, Hamid Sharifi, Mohammad Gerdakaneh, Zeynab Sharifi,
Volume 3, Issue 1 (8-2016)
Abstract
The seeds of two species (Citrulus colocynthis) and (Silybum mrianum) gathered from natural habitat located in the Koohdasht city (Lorestan province) and transferred to Kermanshah Agricultural and Natural Resources Research and Education Center in the summer of 2014. For each species, separate experiments in a completely randomized design with 14 treatments and 4 replications were done. Treatments included moist-chilling time (control, 10, 20, 30, 40, 50, 70 and 90 days at 4 °C), gibberellic acid concentration (200, 400, 600 and 800 PPM) and integrated treatment of gibberellic acid 400 ppm with moist-chilling for 30 days and 70 days. The results showed that for both species increasing of moist-chilling duration and concentration of gibberellic acid significantly increased germination percentage, germination rate and seed vigor index. The best breaking seed dormancy treatment was moist-chilling of 90 days for seeds of (Citruluus colocynthis) and gibberellic acid 800 ppm for (Silybum mrianum). The result showed that seeds of two species had the combination of physiological (related to seed inside inhibitors) and physical dormancy (related to hard coat).
Seyyed Mahdi Javadzadeh, Parviz Rezvani Moghaddam, Mohammad Banayan-Aval, Javad Asili,
Volume 3, Issue 2 (2-2017)
Abstract
Roselle is an important medicinal and industrial plant of the family of Malvaceae, and is planted in vast areas of Sistan and Baluchestan. In a laboratory study, the effect of varying temperatures on seed germination of Hibiscus sabdariffa was investigated and minimum, optimum and maximum temperatures for its germination were determined in a completely randomized design with four replications. For this purpose, temperatures 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50°C were considered in each treatment. Cardinal temperatures for germination were determined consistent with three models (i.e., Intersected-lines Model, Five-Parameters Beta Model and Quadratic Polynomial Model). The traits measured were germination percentage, the speed of germination and mean germination time. The temperature effect on all the measured traits was significant. The results of the regression analysis showed that the best model in terms of cardinal point of this plant is the Five-Parameters Beta Model. Given the results of this model, the minimum and the optimal temperatures for the germination of Roselle are 4.04°C, and 29.83° C, respectively.