Iranian Journal of Seed Research

In order to study the salt tolerance of three species, Coreopsis grandiflora, Celosia cristata and Matthiola incana in germination stage, an experiment was carried out based on a completely randomized design with three replications in Hormozgan University laboratory in 2015. Salinity levels, including 3, 6, 9, and 12 dS/m were applied by dilution seawater and distilled water used as a control. In this research, some seed germination indices such as germination percentage, germination rate and mean germination time, length, fresh and dry weight of seedling, seed vigor germination, were measured. Germination percentage, germination rate, seed vigor and dry weight of Coreopsis grandiflora seedling, were significantly different compared with control. In Celosia cristata, germination percent, seed vigor germination and seedling length didn’t show a significant difference in 9 dS/m salinity. In more characters, significant increases were seen with increasing salinity (9 dS/m). Germination percentage was decreased in comparisons with control (24.6%). In addition, the fresh and dry weight of seedling didn’t show a significant difference. The effect of salinity on seed germination of Matthiola incana in a different level of salinity was not significant. Although seed germination decreases gradually by salinity. In general, according to the observed results, Coreopsis grandiflora and Celosia cristata showed more tolerance to salt in comparison with Matthiola incana.

There have been a few studies on removing the seed pods in annual medics, despite its importance. To investigate the role of pod removal on seed germination, seedling growth and antioxidant enzyme activities in annual medic (Medicago scutellata L.) Under salt stress, a factorial experiment was conducted based on a completely randomized design with four replications in 2014. Salinity at 5 levels: 0.62 (tap water as a control), 3, 6, 9 and 12 dS m^-1 was applied using sodium chloride. The results showed that salt stress caused changes in the characteristics of germination, seedling growth and antioxidant enzyme activities. With increasing in salinity levels, rate and percentage of germination as well as root length, shoot length and seedling weight was significantly decreased. However, increasing salinity levels increased the activity of antioxidant enzymes. Germination and growth in seed without pod was greater than those in seeds with pod; however, there were no significant differences between antioxidant enzyme activity; except about ascorbic peroxide that was significantly higher in seed without a pod. In general, salinity reduced germination and growth and increased antioxidant enzyme activity of annual medics. The results showed that planting seeds without pod had advantages for better germination and growth, especially under saline conditions.

The present study was conducted to investigate the efficiency of hormonal pretreatment on increasing germination and early growth of seedling in the Seed Technology Laboratory of Shahed University in 2015 as a factorial experiment, adopting a completely randomized design with 4 replications. The treatments were: 5 levels of IAA (indole-3-acetic acid) namely, zero, 0.1, 0.5, 1 and 1.5 mg/L and 5 levels of PBA (Tetrahydro pyranyl ­benzyl­ adenine), which were zero, 0.5, 1, 1.5 and 2 mg/L. Analysis of variance showed that the use of the two hormones and their interactions had a significant effect on all traits such as seed germination, biomass, leaf relative water content and photosynthetic pigments. The highest percentage of germination (66.66%) was obtained in 1.5 mg/L IAA with 1 mg/L PBA. 0.5 mg/L PBA and in 0.1 mg/L IAA the longest shoot (1.28 and 1.17 cm, respectively) was obtained. Germination coefficient decreased by about 12.5% by increasing IAA from 0.1 to 1.5 mg/L. The greatest relative water content (42.73% and 37.38%) was obtained with 0.5 mg/L PBA and 1.5 mg/L IAA, respectively. Combination of IAA+PBA (0.1+0 mg/L) had a positive effect on both the length of the root and seedling. The high concentration of PBA and the lowest amount of IAA had similar results in terms of plant biomass. The highest plant biomass (4.33 mg) was obtained in seeds treated with 2 mg/L of cytokinin and 0.1 mg/L of auxin. Photosynthetic pigments were also affected by these two hormones through the IAA was more effective than PBA. The finding was that auxin and cytokinin increase germination and improve the morpho-physiological indicators and thus increase the yield of Stevia.
 

The percentage and rate of germination and proper establishment of seedlings are important factors contributing to higher yield per unit area. As an essential element for plant growth and development, Zinc plays a critical role in many metabolic processes, and also has a positive effect on seed germination. The effects of seed priming with concentrations of 0.5, 1 and 2 percent zinc sulfate on the partitioning of reserved materials in seed, the start of autotrophic seedling growth and the activity of alpha-amylase enzyme were investigated in wheat seeds, using a factorial experiment in the Research Farm of the University of Maragheh, Iran in 2014 on the basis of a completely randomized design with four replications. The results showed that zinc priming had a significant effect on all the parameters under investigation. Mean comparisons showed that an increase in zinc concentration- up to one percent- had a positive effect on the parameters investigated and increasing its concentration more than one percent caused a negative effect on the parameters touched upon above. The results of this study showed that the dry seed weight of the control and zinc sulfate (0.5%) treatment reached a stable level on day 21 and 20, respectively. In addition, in the control and 0.5% zinc sulfate, the total dry weight reached its initial weight (seed weight) on day 15 and 13, respectively. In addition, the growth of autotrophic plant began 10-12 days after soaking. The seeds treated with 5.0 and 1 percent zinc sulfate had more leaf area than the other treatments; this could be due to the earlier entrance of the seedlings produced by 5.0 and 1% zinc sulfate treatments into the autotrophic stage, as compared with other treatments. The results of variance analysis of the finishing seeds' reserved materials, initial kernel, root dry weight and shoot dry weight confirmed that 0.5 and 1% zinc sulfate treatments were better than other concentrations. The treatments of 0.5 and 1%  of zinc sulfate reached the autotrophic stage sooner than the control and 2% zinc sulfate treatment. Given the results of this study, 5.0 and 1% zinc sulfate treatments were selected for field cultivation.
 

This study was conducted to evaluate the effects of accelerated aging and natural storage on seed germination and seedling heterotrophic growth of chickpea in Gorgan University of Agricultural Sciences and Natural Resources in 2014. The experiment was carried out, adopting a completely randomized design with four replications. Treatments were 8 aging levels (i.e., 2 years, and 4 years natural storage; 1, 2, 3, 4, 5 days of accelerated aging and a control). The results showed that the effect of aging treatment on all the traits was significant. Reduction of germination percentage, germination rate, root and shoot length seed vigor index and seedling dry weight of 4 and 5 accelerated aging days was higher than 2 and 4 natural storage years. The electrical conductivity of seed lots increased by an increase in accelerated aging to 4 and 5 days, which was higher than 2 and 4 natural storage years. This is due to incapability of a membrane to keep its permeability, which is the result of the higher sensitivity of seeds to accelerated aging. Reduction of the rate and efficiency of reserves used and also dynamic reserves in natural storage was lower than 4 and 5 accelerated aging days. However, maximum rate and efficiency of reserves used and also dynamic reserves were obtained at 2 accelerated aging days. This could be due to increase in repair reaction rates under these conditions and activation of hydrolytic enzymes in seeds. Finally, the results of the present study revealed that damages to chickpea seed at 4 and 5 accelerated aging days are more than 2 and 4 natural storage years, which leads to the reduction of germination percentage and rate.
 

Asafetida (Ferula assa- foetida L.) is an important medicinal plant belonging to Apiaceae family and has long dormancy. In this research, vernalization, washing time, GA3, medium strength, harvesting time and interaction of these treatments were studied to optimize condition of germination. The results showed that vernalization at 4-5°C for two weeks increased germination by 50%, as compared with the control. Maximum and minimum germinations were obtained for 6 and 2 hours’ washing, which was 42% and 20.47%, respectively. Germination of Ferula was increased (41.5%) by using 10 mg/l of GA3, as compared with the control. In addition, using half strength MS media led to a 25% increase in germination. Moreover, germination mean increased by applying these treatments to one-year-old seeds, in comparison with fresh ones (61% and 36%, respectively). By running factorial experiments in the CRD, the best combination of treatments which could significantly increase germination was a combination of vernalization (4-5°C for two weeks), half strength MS media, GA3 (10 mg/l) and washing time (6h). Given the results of the study, for the purpose of breaking the dormancy of Asafetida, it is suggested that use is made of one-year-old seeds, and half strength MS media, along with right combinations of vernalization, washing time and GA3.
 

For the purpose of evaluating the effect of chitosan on seed germination and some biochemical characteristics of the milk thistle herb in the conditions of salinity, an experiment was conducted as factorial in a completely randomized design (CRD) with three replications in the Laboratory of Seed Science and Technology of Shahed University, Tehran in 2015. Experimental factors comprised salinity levels (0, 4, 8 and 12 dS.m^-1) and different levels of Chitosan (0, 0.25, 0.5, 0.75 and 1 percent). The results showed that salt stress reduced germination percentage, germination coefficient, germination speed, weight and length vigor index, radical, plumule and seedling length and total biomass and increased mean germination time. Seed priming with chitosan up to 0.5% concentration increased germination coefficient, weighted index vigor and plumule length. The highest amounts of total chlorophyll and total protein were obtained in seed priming with 0.5% chitosan levels in zero salinity level (control). By increasing salinity levels, the activity level of catalase and peroxidase increased, so that the highest level of the activity of these two enzymes was obtained in the salinity level of 12 dS.m^-1 in pre-treatment with 0.5% Chitosan. The results showed that seed priming with chitosan of 0.5% could reduce harmful effects of salt stress on some traits of milk thistle seedlings and could even improve their growth.
 

In order to investigate the effect of pretreatment of chitosan biological compounds on seeds of soybean (Glycine max L. cv. Williams) under salt stress conditions, a factorial experiment was conducted, adopting a completely randomized design with three replications at Shahed University in 2015. Factors examined included the combination of chitosan at three levels (0, 0.25 and 0.5 the weight-volume) and salinity at 4 levels (0, 5, 5.7 and 10 dS/m). The results showed that the interaction of chitosan and salinity had a significant impact on seed germination characteristics such as germination percentage, germination rate, mean germination time, normal seedling and physiological characteristics such as proline and soluble sugars of shoots. In contrast to salt stress increase of 30%, and an increase of 24 and 35% of proline and soluble sugars of the shoot, pretreatment of chitosan (0.25%) improves seedling germination characteristics of soybeans. Given the impact of the treatments of chitosan on seed germination and seedling growth of soybean, it is possible to introduce 0.25% W/V chitosan as a treatment to deal with conditions of salinity.
 

1.  The role of maternal sesame plant (cv. Darab 1) foliar application by zinc and boron elements in germination, vigour and storage capability of seeds was studied.
2. The effect of seeds soaked in solutions enriched with zinc and boron elements on germination, vigour and storage capability of seeds was examined.

1. The germination response of six hybrids of the maze to seed deterioration was investigated.
2. The role of antioxidant enzymes in deteriorated seeds of maize hybrids was examined.

To study the effect of production region and seed size on germination indices and heterotrophic growth components of peanut seedling, a study was performed in three peanut fields in Astaneh Ashrafieh and Agronomy Laboratory of Rasht Islamic Azad University from 2010 to 2012. This research was carried out using the standard germination, cold and accelerated aging tests. Tests were performed using factorial experiment with a completely randomized block design in 3 replications. The first factor was seed production region in 3 levels (Noghredeh, Amshal and Bandar-Kiyashahr) and the second factor was seed weight in 3 levels [large, medium and small]. The results indicated that the effect of production region on the germination speed (p<0.01) and coefficient of uniformity of germination (p<0.05) was significant so that the maximum means (6.17 and 18.11 day^-1, respectively) were achieved in seeds produced in Amshal. The effect of the interaction of the region and seed size on the mean germination speed was significant so that the maximum mean (282.22) was achieved in large seeds produced in Amshal. The effect of production region on the seed reserve use rate was significant in standard germination (p<0.01) and cold tests (p<0.05). The effect of seed size on the seed reserve use rate and seed use reserve fraction were significant (P<0.01) in all the three germination tests. The maximum amount of seed reserve use rate was achieved in seeds produced in the Amshal region (in standard and cold tests with averages of 0.562 and 0.440, respectively). In addition, the maximum amount of seed reserve use rate was achieved in large seeds (with averages of 0.541, 0.470 and 0.277 mg per seed in standard, cold and aging tests, respectively). The maximum seed use reserve fraction was achieved in small seeds (with averages of 1.371, 1.310 and 1.664 in standard, cold and aging tests, respectively).

 

Highlights:

1. Peanut seed germination tests were performed based on seed production regions and seed sizes.
2. Three different vigour tests (standard, aging, cold) were used to identify higher quality seeds.
3. Germination indices indicated high quality in large seeds produced in different environmental conditions.
4. Large seeds had the maximum seed reserve use rate and minimum seed use reserve fraction at the germination stage of peanuts.

In order to investigate the effect of different levels of temperature and drought stress on seed germination parameters of nettle roman (Urtica pilulifera L.), an experiment was conducted as factorial in a completely randomized design with three replications at the Department of Agronomy, College of Agriculture, University of Guilan, in 2014. Treatments included different temperature levels (5, 10, 15, 20 and 25 °C) and drought stress levels (0 (control), -2, -4,-6 and -8 bars). The results showed that treatments and their interactions had a significant effect on germination percentage (GP), germination rate (GR), root length and root dry weight. The highest GP (88%), GR (1.8 seed/day) and root dry weight (0.06 g) were obtained as the result of the interaction between the temperature of 25°C and no-stress condition. In this study, with an increase in drought stress and a decrease in temperature, GP, GR, root dry weight, root length and shoot length decreased. The impact of drought stress on GR and GP was lower at 20°C, compared with the temperature of 25°C. A decrease in water potential from -4 to -6 bars at 20°C caused a reduction of 50% and 30% in GP and GR, respectively. However, these reductions at 25°C were 75% and 70%, respectively. According to the results, it could be stated that the significant reduction threshold of seed germination parameters was -2 bars.

 
Highlights:

1. The germination characteristics of Roman nettle were studied under drought stress and temperature.
2. In drought stress of -4 bars, germination percentage and germination rate decreased significantly.

This study was conducted to study the effects of different priming methods on germination rate and percentage under salinity stress and to determine the stability of primed seeds. In order to accomplish this, three different experiments were conducted separately, including the experiment of water uptake, the experiment of salinity stress, and the experiment of storability of primed seeds. Priming treatments were five levels of control (unprimed), hydropriming (Hyd), priming with humic acid (HA), priming with salicylic acid (SA) and priming with gibberellic acid (GA). Salinity stresses were four levels of 0, 4, 8 and 12 ds/m of NaCl. The stability of prime seeds was investigated over a period of 226 days after priming. The results of water uptake showed that rapeseeds entered into the third phase of water uptake after 18 hours of hydration. The results of the salinity experiment showed that salinity levels of 12 and 0 ds/m had the lowest (74.3 %) and highest (83 %) germination percentage, respectively. In terms of germination rate, there were significant differences between GA (0.034 h^-1), HA (0.036 h^-1) and Hyd (0.036 h^-1) with C (0.019 h^-1) and SA (0.027 h^-1). Generally speaking, primed seeds germinated better than control seeds at all levels of salinity. The storability of primed seeds and control seeds had no significant decrease during storage. Finally, it was concluded that seed priming increased the tolerance to salinity stress; in terms of storability, there was no significant difference between primed seeds and primed seeds could be stored in the same way as control seeds.

Highlights:

1. At the current research, the stability of prime seeds was investigated for the first time.
2. There was no significant difference between the storability of primed seeds and control (unprimed) at each sampling time (with an exception for SA).
3. Primed seeds had better germination performance than control at the all salinity stress levels.
4. Seed priming treatments using gibberellic acid, humic acid and hydropriming were the best compared with the other treatments.

1. The effect of hydropriming on recovering the power of seed germination of pinto bean has been studied under the salinity condition.
2. An attempt has been made to determine the effect of hydropriming on increasing the tolerance of pinto bean seeds to storage and salinity stress condition.
3. The effect of pinto bean storage on biochemical changes and enzyme activity has been studied in salinity stress condition.

In order to study the effects of different levels of salinity on germination components of wheat cultivars, a factorial experiment was conducted based on a completely randomized design with three replications. Experimental factors were wheat cultivars at eight levels (Saysons, Gaspard, Finkan, MV-17, Chamran, Sardari, Atila-4 and Azar-2) and six levels of salinity (0, 25, 50, 100, 150 and 200 mM NaCl). The results indicated that salinity had significant effects on all of the traits studied (i.e., radicle length and dry weight, plumule length and dry weight, remaining seed weight after germination, seedling weight, the longest radicle and plumule, number of radicle per seed, ratio of radicle weight to plumule weight and rate, and uniformity and percentage of germination). All of these traits declined with an increase in the salinity (except the ratio of radicle weight to plumule weight, remaining seed weight after germination and seedling weight). The highest ratio of radicle weight to plumule weight, remaining seed weight after germination and seedling weight were recorded in the salinity of 200 mM NaCl. The cultivars showed significant effects on all of the traits studied (except remaining seed weight after germination and seedling weight). Chamran cultivar showed the highest number of radicle per seed, the ratio of radicle weight to plumule weight, rate and percentage of germination. The highest radicle length and the longest radicle were obtained from the Sardari cultivar while in Azar-2 cultivar it was vice versa in plumule. Atila-4 cultivar showed the highest radicle and plumule weight. It seems that compared with other cultivars, out of the cultivars studied, Chamran, Azar-2, Sardari and Atila-4 were more resistant to salinity stress.

 
 Highlights:

1. Introduction of wheat cultivars with more tolerance to salinity conditions at germination stage.
2. Study of eight different wheat cultivars in terms of germination indices under salinity stress conditions.

The present study sought to compare the effect of seed priming by hydropriming, ascorbate and calcium chloride (CaCl₂) versus different concentrations of silver nanoparticles on two Iranian rice cultivars (Hashemi and Shiroodi) under drought stress. The experimental design, which was factorial, was completely randomized. The first factor was control (without priming), hydro-priming, 20 mg.L^-1 calcium chloride, 20 mg.L^-1 ascorbates and 20, 40 and 80 mg.L^-1 of silver nanoparticles. The second factor was the drought stress, including control, -1.48 and -4.91 bars created by polyethylene glycol 6000 solutions. In plants without drought stress, the time required to reach 50% germination (T₅₀) reduced to 34 and 54 percent under ascorbate and CaCl₂ priming in the Hashemi and Shiroodi cultivars, respectively.  In the drought stress condition, ascorbate and hydropriming pretreatments decreased T₅₀ and the time required to reach 90% germination (T₉₀) more than silver nanoparticles, especially in the Shiroodi cultivar. On the other hand, in comparison with other pretreatments, CaCl₂ had an important role in increasing the growth factors in all of the drought stress treatments. Although 40 mg.L^-1 silver nanoparticles increased the growth factors to some extent, it seems that higher levels of silver nanoparticles cause stress in seeds and therefore decrease the seed germination and growth of seedlings. By decreasing reactive oxygen species, Ascorbate improves the germination and by increasing plasma membrane efficiency, CaCl₂ enhances the seedling growth under drought stress.

Highlights:

1. Silver nanoparticles increased the effect of stress on the seedlings of rice cultivars.
2. Ascorbate and calcium chloride improved the germination and seedlings growth of the rice cultivars, respectively under drought stress conditions.

1. The extract of A. sieberi had deterrent effects on seed emergence and morphological characteristics of P. cineraria.
2. Increasing the concentration of the A. sieberi extract led to a decrease in the morphological characteristics of P. cineraria.
3. A. sieberi extract had negative effects on photosynthesis pigments of P. cineraria.