مجله اکوفیزیولوژی بذر
پیاپی 1 (بهار و تابستان 1394)

This study was conducted to evaluate the effects of nano-silicon on germination and early growth of native and improved variety of wheat at laboratory research of Zabol University. Experimental design was randomized factorial design with four replications. Factors were different concentrations of nano-silicon (0, 0.1, 0.2 and 0.3 mM) and different varieties of wheat including Kalak, Afghani and Bolani (native) and Hamoun and Erg (improved).  Nano-silicon application influenced early growth parameters of wheat including root and shoot length, germination percentage, germination rate andseedlingweight. Results indicated that silicon concentration increasing up to 0.2 mM increased studied parameters. Accordingly the greatest seedling length, fresh and dry weight of root and seedlings, vigor index, germinations percentage and germination rate was observed at 0.2 mM silicon.  Interaction of silicon and wheat variety was significant and the greatest influence and the least parameters was achieved at 0.2 mM silicon and Hamoun, and no silicon application and Bolani, respectively. Among wheat variety the greatest and the least parameters was observed in Hamoun and Bolani, respectively. These results suggested that silicon improved germination percentage and evenness of wheat varieties.

Ferula ovina is a medicinal plant belonging to the Apiaceae family that can be used its dry forage as livestock fodder. This plant due to over harvesting from natural pastures has been endanger to elimination. Ferula ovina seeds have a little germination due to seed dormancy.  In order to break seed dormancy an experiment with 28 treatments in a completely randomized design with four replications in seed technology and Agricultural Research laboratories of Birjand University was carried out. Treatments were consisting of 6 and 12 hours of  leaching, chemical scarification with sulfuric acid solution 80% for 5 and 10 min, Potassium Nitrate 0.3% for 72 hours, hormone treatments, Gibberellic acid (250, 500 and 1000 ppm) and Benzyl Amino Porine (0.1 And 0.25 mg per liter), prechilling for 20, 35 and 50 days at +5 °C temperature, and combined prechilling and hormonal treatments. Results showed that the effect of treatments on percentage, rate, mean germination time and seed vigor of Ferula ovina was significant (P≤%1). prechilling was an essential factor for dormancy breaking of Ferula ovina seeds. Hormonal treatments improved seed germination characteristics.  The best treatment for Ferula ovina seed dormancy breaking was 50 days perichilling with 500 ppm GA3 at +5 °C temperature.

The present study was conducted in order to evaluate the effect of seed priming on germination and heterotrophic growth of wheat seedling in drought stress conditions at at factorial experiment based on complete randomized design at Faculty of Agriculture, University of Maragheh. Experimental treatments were of five levels of drought (0, -3, -6, -9 and -12 Bar) and three levels of potassium nitrate (KNO3) (0, 2 and 4 percent). The results showed that rate the percentage of germination reduced with increasingstress levels. Effect of seed priming on germination rate and the mean germination time was positive in control level(0 bar), but the positive effect unobserved with increasing severity of drought. So that the lowest germination rate and maximum mean germination time was in -12 bar. Investigation of components heterotrophic growth revealed that the prime with of 2 % concentration potassium nitrate have the most significant effect on drought tolerance at traits seed reserve utilization rate, seed reserve utilization efficiency and seed reserve depletion percentage. Also the vigor index and seedling dry weight in treatments primed at levels of 2% potassium nitrate in drought levels was observed most significant change. Therefore can stated that seed priming with potassium nitrate via positive effect on heterotrophic growth of wheat seedling under drought stress may desirable performance under drought stress in wheat growth.

The seeds germination response to temperature is different between plant species. The germination process in different plants occurs in a wide range of temperature. The cardinal temperatures have an important role in the selection of suitable climate, time and places for seed planting. Given that the replacement of soybean by Green Pea is important for supply the required protein in dry lands. Evaluation of cardinal temperatures for germination of this plant can helps to better planting and timely seeding in the field. With this aim, an experiment based on completely randomized design was conducted with 4 replications in the faculty of agriculture of Birjand University. The treatments were 5, 10, 15, 20, 25, 30 and 35 degree of centigrade temperatures. The results showed that the maximum of germination rate was observed at 30 degree centigrade. In the temperature range of 15 to 30 degree centigrade observed high germination percentage. But, by reducing the temperature to below 15 degree of centigrade and increase it to more than 30 degrees, the germination percentage are significantly reduced. To determine the cardinal temperatures was used from three models including Intersected Lines, Quadratic Polynomial and Five Parametric Beta Regression. The Beta regression model was better described by temperature changes than the germination rate. In addition, the base, optimum and maximum temperature was 4.47, 28 and 35 degree of centigrade respectively.

In order to investigate the effect of priming techniques on germination paramaters of seed were evaluated germination and growth the effect of hydropriming coneflower seeds in terms of salinity.Factorial experiment in a completely randomized design with three replications in Seed Technology Laboratory, Faculty of Agriculture controls.  The factores was inclouded from four levels of non-primed, 10, 20 and 30 hours priming seed and five salinity levels with distilled water (control), 3, 6, 9 and 12 ds/m natural salt lake in Qom. Analysis of variance showed that the interaction between priming and salinity data on the percentage of germination, shoot and root dry weight of shoot and root and seed vigor was significant. Percent germination rate and increase the duration of priming and salt stress than non-primed seeds fell. But hydropriming treatment for 10 hours significantly increased salinity 3 ds/m rate and percentage of germination, shoot and root and seed vigor was. The hydropriming treatment for 10 hours under salt stress shoot and root dry weight increased 6 ds/m what happened. Thus, according to the priorities of germination or growth of root and shoot, as well as the cost of seed priming can be hydropriming treatment for 10 hours under salt stress 6 ds/m as the most favorable for seed germination hydropriming coneflower recommended.

Different cardinal temperatures for germination has caused asynchronous appearance of weeds in fieldand so different appropriate management practices to control them, to avoid their invasion. So, in order to study the cardinal temperatures of germination in Atriplex dimorphostegia, Salsola crassa and Suaeda aegyptiaca seeds and effect of different temperatures on their germination characteristics, an experiment was carried out at research laboratory of Faculty of Agriculture in University of Birjand in 2013. The study was conducted based on completely randomized design with 8 levels of temperature (5, 10, 15, 20, 25, 30, 35, and 40○C) and 4 replications. The results of quadratic and dental models showed that cardinal temperatures of germination including base, optimum and maximum temperatures for Atriplex dimorphostegia were 5.57, 26.37, 47.07○C, for Salsola crassa were 3.48, 21.57 and 39.66○C and for Suaeda aegyptiaca were 6.96, 28.81 and 44.52 ○Crespectively. Effect of temperature on all indices of germination in all three weeds were significant (P<0.01) Reduction of percentage and rate of germination at the least temperature compare to the most temperatures in which germination was occurred, were 39.40% and 33.99 %, in Atriplex dimorphostegia and 86& and 66.29% in Salsola crassa and 87.04%, and 94.31% in Suaeda aegyptiaca respectively. The most germination uniformity was occurred at 20○C, 15-20 ○C and 20-40○Cin Atriplex dimorphostegia, Salsula crassaand Suaeda aegyptiaca respectively. Difference between minimum and maximum of Seedling shoot and root length, and Seedling fresh and dry weight were 94.52, 91, 85 and 98.57 percent in Atriplex dimorphostegia, 63.09, 70.12, 71.52, 53.85percent in Salsola crassa and 86.33, 93.99, 96.67 and 99.33 percent in Suaeda eagyptiaca r. The highest seedling vigor index was occurred at 20 ○C in Atriplex dimorphostegia and Salsola crassa and at 10 ○C  in Suaeda aegyptiaca.