نشریه علوم و تحقیقات بذر ایران
سال ششم شماره 1 (بهار 1398)

In order to evaluate seed germination, seedling emergence and changes in growth indices of borage in response to seed priming and water limitation, laboratory tests were laid out as completely randomized design with four replicates and field experiment was carried out as split plot based on randomized complete block design with three replications in 2012. Irrigation treatments (I1, I2, I3 and I4: irrigation after 60, 90, 120 and 150 mm evaporation from class A pan, respectively) and seed priming methods (P0: unprimed, P1: hydro-priming, P2: priming with 100 mM KNO3, P3: priming with 100 mM KH2PO4 for 8 h at 15±1°C) were allocated to main and sub plots, respectively. Results indicated that seed hydro-priming increased germination rate and seedling dry weight of borage by 15.9% and 22.6%, respectively. Emergence rate of borage seedlings was also improved about 7% under different seed treatments. At vegetative stage, leaf area index of plants from seeds primed with water, KNO3 and KH2PO4 was 22.8, 39.7 and 16.1% higher than that of unprimed seeds. At flowering stage, water loss of the plants decreased under water deficit conditions by reducing the leaf area index. All priming techniques, especially hydro-priming, improved leaf area index, particularly under well watering, through increasing seedling emergence rate. Dry matter accumulation, relative growth rate and crop growth rate decreased with increasing irrigation intervals. However, growth duration of plants from primed seeds was longer than those from unprimed seeds, leading to the production of larger plants under well watering.

In order to protect environment and improve plant growth under drought stress conditions, an experiment was conducted as factorial in a completely randomized design with three replications on Niger )Guizotia abyssinica (L.F) Cass( seed at the research greenhouse of Shahrekord University in 2015. Physically pre-treatment as a seed placement in different magnetic field intensities including 0, 50, 100, 150 and 200mT (at 5 minutes time) as the first factor and  irrigation intervals at three levels of 2, 4 and 6 days as the second factor were considered. The effect of magnetic field, drought stress and their interaction were significant on all of the evaluated characteristics. The maximum root dry weight in 150mT field intensity under 2 days irrigation intervals, the maximum leaf dry weight, root length and number of flower in 100mT field intensity under 2 and 6 days irrigation intervals, respectively, the maximum content of chlorophyll a and (a+b) and carotenoids in 50mT field intensity under 6 days irrigation intervals, the maximum content of chlorophyll b in 150mT field intensity under 4 days irrigation intervals and minimum malondialdehyde content in 200mT field intensity under 2 days irrigation intervals were obtained. The maximum number of flowers (as the most important index on increasing yield) were obtaind at 200mT fields intensity for 2 and 4 days and at 50 and 100mT fields intensity for 6 days irrigation intervals. In general, it can be said application of magnetic field with moderate intensities can alleviate stress conditions.

Because of small and low quality seeds, St Johns wort (Hypericum perforatum L.) have not favorable establishment in the field. In these study effects of different seed enhancement treatments were applied on the seeds and relationship of emergence with germination characteristics and amylase activity were evaluated. A factorial experiment was conducted in randomized ccompletely design with four replications. Osmopriming with Polyethylene glycol 6000 in five levels (0, -3, -6, -9 and -12 bar) were conducted as first factor and application of Gibberellic acid at four concentration (0, 500, 1000 and 1500 ppm) as second factor. Analysis of variance showed that polyethylene glycol, gibberellin and their interaction had significant effects on germination and emergence of St Johns wort seeds. Continuous application of PEG and GA had most favorable effect on germination, emergence, vigor and Amylase activity compared to the control and separate application of them. Concentration of 1000 ppm of gibberellin in -12 bar of osmotic potential caused to highest germination (91.5 %), emergence (80.5 %), seed vigor (32.08) and amylase activity (25.21 starch breakage percentage). While the control showed lowest performance in all measured traits. Correlation analysis showed a positive and significant correlation between seedling emergence of and germination percentage (r=0.89**), seed vigor (r=0.95**) and amylase activity (r=0.92**) of St Johns wort seeds. Based on the results, it is seems that application of priming techniques improve establishment of St Johns wort seeds via increasing germination, seed vigor and amylase activity.

To evaluate the effects of seed priming and durability on the germination and yield of corn, two separate studies were conducted in laboratory and field conditions. The first experiment, the effect of six priming treatments (priming with tap water, homeopathic urea, zinc sulphate, magnetic water, Aminol Forte and untreated seeds) and Durability of six seed (without lasting, lasting for one, two, three, four, five weeks) On germination characteristics of maize single cross 260 (hybrid Fajr) in 1392 in seed technology laboratory Faculty of Agriculture, University of Kurdistan were studied. In a second experiment, the effect of priming the hybrid Fajr yield during the years 1392 till 1394 were evaluated in Kurdistan University Research Farm. The results showed that by increasing the Durability of characteristics such as germination percentage and speed of germination and seedling vigor index decreased significantly. The reduction of these traits after six weeks, the durability approximately 20, 24 and 77 percent respectively compared to those with no durability. On the other hand priming treatments had no significant effect on germination percentage, but in contrast to tap water, homeopathic urea, zinc and magnetic water priming treatments significantly increases the speed of germination, seedling length, by 14 and 155%, respectively. The results of field experiments show the effect of the above priming treatments were evaluated on yield in all years. Amount of grain yield increased about 12 percent compared to control priming treatments. According to the results, seed priming than no priming has priority that among these tap water treatment has the greatest impact. Also after priming seeds of the plant should act as soon as possible.

This study was conducted as a factorial experiment to evaluate the effect of seed priming and osmotic stress on the activity ofhydrolytic and glyoxylate cycle enzymesin maize based on completely randomized design in  2012 at College of Agriculture, the University of Mohaghegh Ardabili. Treatments were four levels of osmotic stress originated from PEG 6000 (0, -3, -6 and -9 bar) and five levels of priming (Control, hydropriming, osmopriming, hormone priming and ascorbic acid) in three replications . The results showed that interaction of drought stress and priming was significant on all traits except of Germination Percentage and  isocitratelyase activity (only single effect of osmotic stress and priming was significant). The highest germination rate (17.556 seed day-1) observed in control drought. The highest activity of amylase, lipase and protease (4.43, 73.2 and 2071.3 unit mg-1 protein, respectively) observed in hormone priming and non-stress conditions. The lowest amylase activity (3.1 unit mg-1 protein) was related to osmo-priming and -9 bar drought while the lowest activity of lipase and protease (60.36 and 1949 unit mg-1 protein, respectively) observed in -9 bar drought in non-primed seeds. The highest activity of malate synthase (2.7 unit mg-1protein) observed in hormone priming and non-stress conditions, but the lowest activity (1.88 unit mg-1 protein) was related to -9 bar drought stress and non-primed seeds. Increase in the severity of stress decreased the germination rate and the activity of enzymes. Seed priming with gibberellic acid caused to resistance to drought conditions and prevention of decrease in the activity of hydrolytic and glyoxylate cycle enzymes in maize seeds

In order to evaluate the effect of safflower aqueous extracts on seedling growth and enzymes activity of wild oat and barnyard grass, this experiment was arranged in a completely randomized design (CRD) with five replications in 2 separated experiments. Effect of different concentrations of safflower extracts (0, 10, 20, 30 and 40%) were examined on seed germination characters of wild oat and barnyard grass weeds. The results showed that in the concentrations of 30 and 40% of safflower aquatic extract, wild oat germination was 33.3% and 46.6%, respectively, and significantly decreased in comparison with control (93.3%). While, under 30 and 40% concentrations, barnyard grass germination was 30% lower than control treatment. Safflower extract reduced the activity of α-amylase enzymes in barnyard grass seeds. The activity level of α-amylase enzymes and wild oat seedlings in the treatment of 40% safflower extract was 2.2 and 1.9 nmol / g protein / min, respectively. Increasing the concentration of safflower extract resulted in degradation of cell membranes, increased free fatty acid levels, and decreased activity of barnyard grass catalase enzymes. In general, the allelopathic compounds in the aqueous extract of safflower reduced the amount and speed of germination of wild grasshoppers and wild oat by reducing the activity of α-amylase enzyme and increasing the peroxidation of membrane fats. Germination and seedling growth of wild oat compared to barnyard grass were more susceptible to safflower extract.

Seed priming has been used to improve germination and to enhance seedling vigour of field crops especially under environmental stresses. The present research was designed in order to evaluate the advantage of seed priming with calcium and zinc on seed germination indices and seedling growth of black cumin under salt stress. For this purpose, a factorial experiment was carried out based on RCB design with four replicates. Experimental factors included five priming methods (non-priming control, priming with calcium nitrate, nano zinc oxide, calcium nitrate+nano zinc oxide and hydro-priming) and three salinity levels (0, 50 and 100 mM NaCl). In this experiment, seed germination indices, sodium, potassium and calcium content of seedlings and peroxidase activity of seedlings were measured. The results of the present research indicated that despite the inhibitory effect of salinity on black cumin seed germination and seedling growth characteristics, seed priming substantially alleviated the deleterious impacts of salt due to enhancement of prescribed parameters. When NaCl concentration increased, K and Ca contents of seedling was reduced and Na amount and guaiacol peroxidase activity was increased, while seed priming caused increase of K and Ca and decrease of Na under salinity. Among the applied priming methods, seed priming with calcium nitrate+nano zinc oxide had the highest efficacy and the best performance in ameliorating inhibition of measured parameters of black cumin induced by salt.

Existence of copper sulfate in water and soil could leads to decreasing of germination and seedling establishment and also reduction in growth and crop productivity. A factorial experiment was conducted as a completely randomized design with three replications in agriculture faculty of Yasouj University. Experimental factors were included different concentrations of copper sulfate (0, 10, 20, 30 and 40 mg per liter) and different cultivars of wheat (Arg, Bahar, Back cross roshan and Roshan), respectively. The results indicated that the most length vigor (23.88), weight vigor (18.54) and dry weight of seedlling (18.54) were obtained from Roshan cultivar in 0 concentration of copper sulfate. Also the highest slouble sugars content (1.49 µmol/g) was achieved from Back cross roshan cultivar in 40 concentration of copper sulfate and the most amount of proline (0.79 µm/g) from Bahar cultivar in 40 concentration of copper sulfate. Among the main effects of copper sulfate the highest seed consumptive reserve (18.45 mg), seed reserve utilization efficiency (0.77 mg/mg seed) and seed reserve depletion percentage (53.1 percent) was obtained form 0 concenteration of copper sulfate and among the different wheat cultivars the most seed consumptive reserve (18.10 mg) and seed reserve depletion percentage (39.89%) form Roshan cultivar, the highest seed reserve utilization efficiency (0.76 mg.mg-1 seed) from Arg cultivar and the most germination rate (10.94) were obtained from Back cross roshan cultivar. Among the different wheat cultivars, Roshan and Back crass roshan cultivars in terms of tolerance to copper sulphate were superior to Arg and Bahar cultivars.

To evaluate the effect of maternal plant growth environment on the establishment and seed vigor of barley (Hordeum vulgare L. cv.Torkaman) after the warehouse storage, an experiment was conducted factorial y based on complete randomized block design in three replications. The irrigation treatments, included full irrigation, moderate stress (witholding flowering stage) and severe stress (witholding from flowering to harvest), and fertilizer treatments includedcontrol (without fertilizer), bio-fertilizer, organic fertilizer, chemical fertilizer, combination of bio-fertilizer with the chemical fertilizer and combination of organic fertilizer with chemical fertilizers. Seed vigor were measured after five years storage. The drought stress imposed on the mother plant reduced the seedling field emergence after storage, while the plants under moderate drought stress which received the integrated fertilizing system of vermicompost and chemicalfertilizer , in short time (8.25) had the highest seedling field emergence (99.8), although results of the seed vigor and seedling establishment  befor and after storage indicated that germination of the seeds which recieved biological fertilizer alongwith  chemical and grew under mild and severe water stress did not reduce after storage.

Accelerated aging test is the most important test used to evaluate the physiological potential of seeds of various species and provides related information about their adaptability degree.In this research, the effect different fertilizer, biochar and Trichoderma fungus treatments was investigated on germination and other seed germination components of corn KSC 704 under accelated aging test,This experiment was conducted as  split–plot factorial based on randomized complete block design with three replications to determine the changes in maize’s seed quality on the parent plant at Jiroft's Nemooneh Field in 2016. The main factor was four levels of fertilizers NPK respectively representing the control (no Fertilizer), 30%, 70%,and 100% of recommended value (Urea 400, superphosphate trepil 100 and potash 150 kgha-1), while biochar(with biochar and no biochar) (20 kgha-1),and three strains of control (no Trichoderma) and Trichoderma (Trichoderma atroviride and Trichodema harzianum) were assigned to sub plots. To assess the quality of maize seeds KSC.704 hybrid produced on the parent plant, accelerated ageing test (including normal seedling percentage, germination rate, seedling length and weight) were performed. The results showed that utilization of biochar, Trichoderma strains and fertilizer levels significantly affected normal seedling percentage,MGT, seedling length vigor index and seedling weight vigor index in accelerated ageing test and the highest seed quality was obtained via combined treatment of using biochar, Trichoderma (Trichodema harzianum) and 70% of the recommended fertilizer dose. According to the results obtained in the control treatments (no fertilizer) and fertilizer application (as 30, 70 and 100% of recommended fertilizer dose,Trichoderma and biochar treatments did not affect the amount of fertilizer used, but increased the fertilizer use efficiency