نشریه پژوهش های بذر ایران
سال چهارم شماره 1 (پیاپی 7، بهار و تابستان 1396)

An experiment was conducted to investigate the effects of jasmonic and humic acids on some seed germination characteristics of Roselle under the salt stress condition in a factorial experiment, adopting a completely randomized design with three replications. Treatments included four different levels of salinity stresses: 0, 70, 140 and 210 mM; four levels of Jasmonic Acid: 0, 50, 150 and 200 mM and three levels of humic acid: 0, 40 and 80 mM. The results showed that the effect of salinity on all the traits studied was significant except the ratio of the length of root and shoot. With an increase in salinity stress condition from 70 to 210 mM, there were 39% decrease in germination percentage, 55% in germination rate, 45% in fresh and dry weight, 30% in root length, 42% in shoot length, 37% in seedling length, 67% in longitudinal index and 61% in the weighted power, as compared with the control. However, the longitudinal power index increased. In addition, the use of jasmonic acid and humic acids had a significant effect on the traits studied. The interaction of the salt and hormones had a significant impact on plant fresh and dry weight, the length of the root, germination percentage, power weight index and average time needed for 50 percent germination. Given that the highest rate of root length and plant fresh and dry weight belonged to the interaction of humic and jasmonic acid in the absence of salinity, that in the presence of humic acid (with 80 mM concentration), Rosselle can bear salinity up to 140 mM and maintain stamina root length and that the germination rate of Rosselle increases by adding jasmonic acid up to 200 mM, one can conclude that the interaction of jasmonic and humic acids not only improves germination rate, but it also contributes to root length because, with an increase in root length, Rosselle can bear water stress conditions.
Highlights: 1. Jasmonic acid and humic acid increase the Rosselle germination in salinity condition.
2.Jasmonic acid and humic acid increase Rosselle the root length in salinity condition.

Weeds pose a serious threat to farmers. Using allopathic properties of the plants, especially those of the medicinal plants, has an important role in controlling weeds. This study was conducted to examine the allelopathic potential of Achillea wilhelmsii in germination of Hirshfeldia incana and Hordeum glaucum. A factorial experiment was conducted, adopting a completely randomized design with three replicates in both libratory and pot cultivation. Organ extracts (flower, leaf and root) of Achillea wilhelmsii in four concentrations were used, namely: 1, 2 and 5%. In addition, distilled water was used as a control. The result showed that the greatest percentages of the germination of Hordeum glaucum and Hirshfeldia incana were in the distilled water, which were 100 and 91%, respectively and that their germination reached zero percent under extraction of leaf and flower with a concentration of 5%. The concentration higher than 2% of the extraction of Achillea wilhelmsii significantly decreased germination, length of radicle and aerial part, fresh and dry weight of shoot and root, leaf area index and amount of chlorophyll in Hordeum glaucum and Hirshfeldia incana, in contrast with distilled water. The results showed that leaf and flower extraction of Achillea wilhelmsii had allopathic effects. In addition, it had impacts on germination and growth of the seeds of Hordeum glaucum and Hirshfeldia incana, which could be used in the production of natural herbicides.
Highlights: 1. Aqueous extrac of Achillea wilhelmsii significantly decreases germination and growth of Hordeum glaucum and Hirshfeldia incana.
2.Aqueous extrac of Achillea wilhelmsii can be used to produce the natural herbicides.

Salinity is one of the environmental stresses limiting rice cultivation. Evaluation of the tolerance and sensitivity of offsprings of segregated generations under salinity condition is one way of finding tolerant cultivars. In order to study the effects of salinity (80 mM NaCl) stress on the second generation offspring of crosses of three rice varieties (Dollars and Gharib with 304) and to compare them with their parents and their classification in terms of salinity stress, the first experiment was conducted, adopting a Completely Randomized Design with four replications (i.e., crossing parents with Yasouj and Kamfirooz varieties). In the second experiment, check cultivars and the second generation progeny were evaluated, using an augment with a completely randomized design. At the germination stage, the Dollar cultivar was sensitive to salinity stress because it had the lowest ratio of all traits except germination percentage. However, Gharib and Kamfirooz Cultivars were salt tolerant. In both crosses, second-generation offsprings showed genetic variations in terms of the traits measured. Broad-sense heritability values for Dollars×304 and Gharib×304 crosses for shoot height (5.98% and 96%), root length (8.90% and 86%) and shoot fresh weight (8.95% and 7.92%), were relatively high, indicating that we can select these traits based on their phenotypes. General irritability for the shoot and root length traits in the second generation offsprings of Dollar and 304 crosses was higher than that of the second generation progeny of 304 and Gharib crosses. Based on these results, we concluded that for the purpose of improving salt tolerance at germination stage, 304 and Dollars crosses are more useful in rice breeding programs.
Highlights: 1.For the first time, an augment design was adopted in an experimental study to investigate the non-repeat genotypes in the generations.
2.The tolerance and sensitivity of genotypes were evaluated, consistent with the definition of statistical intervals.
3.The results of this research led to the introduction of superior crossings for replications at the farm level.

Unfavorable storage conditions, especially relatively high environment humidity and high storage temperature greatly affect the quality of corn seeds. The effects of temperature, environment moisture and length of storage on six maize hybrids were examined. For the purpose of investigating germination traits, total soluble proteins, leakage electrolytes and the activity of antioxidant enzymes in maize hybrids, an experiment was carried out at the Agronomy and Plant Breeding Laboratory of Ilam University in 2016. The study was conducted as two factorial experiments, adopting a completely randomized design with three replications. The first factor comprised six maize hybrids (single crosses: 703, 706, 711, 604, Mobin and 701) that were obtained from Karaj Seed Breeding and Seedling Institute, Iran. The second factor was accelerated aging test in four levels involving non-aging (control treatment), aging for 4, 8 and 12 days under 40°C temperature and 95% humidity. The results showed that mean time to germination and electrolyte leakage significantly increased with aging duration. Mean time to germination and electrolyte leakage of the hybrids 701, Mobin and 711 increased more than the other hybrids. In addition, antioxidant enzyme activity decreased significantly with an increase in the aging period. These results indicated severe damage to cell membranes and enzyme activity in these hybrids. Moreover, there was a significant and positive correlation between germination percentage and the enzyme peroxides, as compared with other antioxidant enzymes. Although antioxidant enzyme activity exhibited a significant reduction in seed deterioration, nonetheless, generally speaking, compared with other varieties, KSC 703 was more tolerant.
Highlights: 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.

In order to evaluate the allelopathic effect of aqueous extract of nine weeds species on Anise (Pimpinella anisum) seed germination and seedling growth characteristics, an experiment was conducted in the Laboratory of Yasouj University in 2014. This experiment was carried out as factorial with the aqueous extracts of nine weeds species, as the first factor, in different concentrations (10, 20, 30, 40 and 50 g.l-1), as the second factor, in a completely randomized design with four replications. The results showed that interactions between different weed aqueous extracts and concentrations had a significant impact on the germination percentage and rate, root and shoot length and weight, and vigor of anise seeds at 1% probability. The most allelopathic effects on germination percentage and rate were observed in 10 g/l of the aqueous extract of Cowherb and Corn Buttercup, in 20 to 30 g/l of Corn Buttercup and Whitetop, and in 40 to 50 g.l-1 of Corn Buttercup, Whitetop, Wild lettuce and Cowherb, which completely stopped seed germination in Anise.
Highlights: 1. Allelopathic effects of 9 common weedy types on germination of Anise Seed were studied in Kohgiluyeh and Boyerahmad.
2.The effect of different concentrations of aqueous extracts of weeds on germination characteristics of anise was studied.

In order to study drought stress effect at the reproductive stage on seed germination characteristics of seven rice genotypes, an experiment was carried out at Sari Agricultural Sciences and Natural Resources University in 2014. This study was conducted on drought-stressed seeds and seeds grown under normal conditions. The results of orthogonal mean comparison among non-stressed seeds showed that local genotypes had a lower germination index, germination rate, water percentage of seedling tissue, shoot length and root dry weight than the improved genotypes. Among stressed seeds, however, local genotypes had a higher germination index and germination rates than those of improved genotypes. Comparison of non-stressed seeds of susceptible and tolerant genotypes indicated that susceptible genotypes had a higher germination index, germination rate and germination percentage than tolerant genotypes. On the other hand, the comparison of the stressed seeds of susceptible and tolerant genotypes revealed that drought stress increased the time to 10, 50, 90 and 95% germination, water percentage of seedling tissue and plantlet length in susceptible genotypes, which were higher than those of tolerant genotypes. In conclusion, it seems that drought stress at reproductive stage has a significant effect on germination characteristics of the plant’s following generation. However, their responses are different, depending on the level tolerance of the genotype to stress and genetic origin.
Highlights: 1- Drought stress at reproductive stage has a significant effect on germination characteristics of the following generation of the rice plant.
2- Among stressed seeds, local genotypes have a higher germination index and germination rates than those of the improved genotypes.
3- Drought stress increases the time of germination in susceptible genotypes, which is higher than that in the tolerant genotypes.

Micronutrients play a great role in the production of high quality seeds, especially in terms of germination. Therefore, providing seeds with sufficient amounts of these is an important consideration in seed production. The present study was conducted as two separate experiments in the Seed Laboratory of Yasouj University in 2015. In the first experiment, the sesame seeds (cv. Darab 1) obtained from a previous split plot experiment based on RCBD, consisting of three irrigation levels (after 75, 110 and 145 mm evaporation from class A pan) and four foliar applications comprising water, zinc sulfate, boric acid and mixture of zinc sulfate and boric acid, were investigated in germination experiments in the minimum temperature (i.e., 15°C). The second experiment was a factorial based on RCD with three replications. The first factor in the eight levels included seeds soaked in water, ZnSo4, H3Bo3 and ZnSo4 H3Bo3 and seeds with high contents of Zn (159 m Kg-1), B (15.3 m Kg-1) and Zn (139.5 m Kg-1) B (14 m Kg-1) and dry see as the control. The second factor was accelerated aging periods at three levels (0, 2 and 4 days) at 45°c and RH = 100%. The results showed that with a delay in irrigation time, compared with water foliar application, foliar application of micronutrients (Zn, B, Zn), and significantly increased germination traits. The results also suggested that, compared with seeds soaked in nutrients, seeds with high Zn and B contents significantly increased germination indices and antioxidant (catalase and peroxidase) activities, especially under accelerated seed aging.
Highlights: 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.

The present study was conducted to evaluate the impact of drought and salinity stresses on germination, seedling growth and cell membrane stability of anise (Pimpinella anisum) and fennel (Foeniculum vulgare) in two separate experiments, using a completely randomized design with three replications in Islamic Azad University, Shoushtar Branch in 2013. Drought stress was applied by PEG 6000 and included 0, -2, -4, -6 and -8 bar and salinity treatments were 0, 40, 80 and 120 mM NaCl solutions. Salt and drought stresses significantly reduced germination percentage and seedling fresh weight of anise and fennel, but increased mean germination time and seedling electrical leakage. The results showed that the highest salinity and drought stresses levels increased seedling electrical leakage of anise by 83% and 76% compared with the control conditions. Moreover, seedling electrical leakage of fennel increased up to 77% and 75%, as compared with the control. The results showed that at germination stage, salt and drought stresses increased cell membrane damage, but decreased anise and fennel seedling growth.
Highlight: 1. Variations in concentration and the rate of destruction of seedling membranes of anise and fennel plants were studied in response to environmental stresses.
2.The germination characteristics of anise and fennel were studied under salt and drought stresses.

To investigate the role of seed size on maize germination characteristics, an experiment was conducted in 2014 in the Laboratory of Registration and Certification of Seeds and Plants, Khuzestan Branch. Treatments included three levels of seed size (control (mixed), large and small) and hybrids at three levels (KSC704, Karun and Mobin). The results of these experiments showed that the hybrid had a significant impact on germination percentage, the rate of germination, vigor index, root and shoot length and dry weight of seedling. In addition, the highest germination (94.3%), the rate of germination (8.4 seeds per day), vigor index (37.6), shoot length (21 cm), root fresh weight (3.1 gr) and dry weight of seedlings (0.59 g) affected by seed size belonged to the Karun hybrid. Generally speaking, in terms of germination and seedling growth, there were differences among the three groups of maize seeds. Out of the hybrids scrutinized, Karun hybrid was a better one in terms of germination and growth of seedlings.
Highlights:1. Due to higher storage capacity, the use of large seeds brings about increases in the seedling germination rate and their establishment in the field
2.The use of large seeds with more seed vigor decreases competition between seedlings and reduces vapor from the field.