SEED RESEARCH (JOURNAL OF SEED SCIENCE AND TECHNOLOGY)
Year:2012 | Volume:2 | Issue:3|Papers Count:8

In order to evaluate Triticale (Triticosecale wittmack) seed size effect on germination under stress condition, two experiments were conducted in factorial arrangement based on completely randomized design with three replications in Faculty of Agriculture of Bu Ali Sina University, Hamedan. In both experiments and factors included seed size in three levels (Small, Medium and Large) and stress in five levels (0, -0.2, -0.4, -0.6 and -0.8 MPa). In the both experiments salinity and drought stress levels in 1st and 2nd experiments produced respectivelyby sodium chloride and PEG6000, germination percentage, germination rate, radicle length, plumule length and seedling dry weight was reduced by increasing stress. Under salinity stress, decline slopes of mentioned traits were more negative than drought stress. Germination rate, radical length and seedling dry weight of small seeds were significantly less than medium and large seeds. Under drought stress only germination rate of small seeds had only significant difference with two other groups. In both experiments, interaction effects of stress and seed size had no significant difference. High correlation observed between seed germination rate with plumule length, radicle length and seedling dry weight traits. In general, under salinity and drought stress levels didn’t show difference in germination traits between three seed gropes.

In this study, the effects of stratification in low temperature, gibberellic acid (GA3) and scarification by sulphuric acid was studied on seed germination of three barberry genotypes that pointed by R2N1, R5N1 and R9N3 cods and belong to Berberis integerrima, B. crataegina´integerrima and B. crataegina respectively. The results showed significant increasing of simple effects (p=0.001), genotype, gibberellic acid (GA3), acid scarification and low temperature stratification, on seed germination. R9N3 have lower germination compare to other genotypes. The seed germination of R9N3 in the best condition, 90 days stratification and acid scarification, was only 26 percent. Highest seed germination 70% in R5N1 was obtain after acid scarification and 45 days stratification while best seed germination percent of R2N1 with 76 percent was obtain in 90 days stratification without scarification. Barberry genotypes have high diversity in seed germination. The most important factor in barberry seeds germination is low temperature stratification.

Common beans (Phaseolus vulgaris L.) is one of the most important crops of the legume family and one of the major Sources of Calorie and protein in human nutrition. It contains polyphenols, anthocyanins and flavonoids which are important in terms of the food and pharmaceutics. In this study, 56 common bean genotypes with three colors (white, pinto and red) were studied by using complete randomized design at three replications for measurement of total polyphenols, seed weight and seed size (length, width and thickness). Data analysis showed that for total polyphenol, seed weight and grain size were significant differences (P£0.01) between three kinds of beans. Positive and significant correlation were observed a mong total polyphenol and 100 seed weight, width and thickness grain. Cluster analysis, using UPGMA procedure, formed two different groups based on studied characters in 56 genotypes. First group contained all genotypes of white and red beans except four genotypes (11, 18, 50 and 52) with two genotypes of pinto bean (19 and 20) and second group contained all genotypes of pinto bean (except above mentioned genotypes). Total seed polyphenols ranged from 15.31499 to 15.06549 mg GAE g-1, 100 seed weight from 29.27 to 44.90 g, grain length from 1.162 to 1.316 cm, grain width from 0.689 to 0.837 cm and grain thickness was between 0.512 and 0.652 cm. Generally, total polyphenols of grain in red and pinto beans were more than white bean. Seed weight in pinto bean was significantly more than red and white beans. Color types of common beans had not significant different in seed size.

To study the effects of priming by water and potassium nitrate on germination and sprouting traits of cotton (Sahel cv.) in salinity stress, two laboratorial and greenhouse studies were carried out as factorial experiments based on a completely randomized design with four replications. Treatments were included hydro priming (with distilled water), priming with 3 and 6 g potassium nitrate l-1 and three levels of salinity stress (0, 4 and 8 dS m-1 induced by sodium chloride). The results showed that hydro priming and priming by potassium nitrate led to increase of final germination and emergence percentage, length of radicle and plumule, seedling and plant dry weight, leaf area and mean height of plant at the salinity stress. Also, mean germination and emergence time were reduced by seed priming. At the highest level of salinity stress, priming with 6 g KNO3 l-1 had the most positive effects on measured traits. In per experiment, there was robust and significant correlation (p<0.01) between mean germination and emergence time with each one of plant traits and special seedling dry weight or plant dry weight. In non-stress condition, in some traits, hydro priming was better than other treatments; But at highest level of stress, priming with 6 g KNO3 l-1 had majority positive and significant effects in most of measured traits.

Priming, is one of the most applicable methods for enhancement of seedling attributes under stress conditions. This experiment was conducted to determine the effect of hydro priming and urea osmo priming on germination attributes of tall wheat grass (Agropyron elangatum). Two separate factorial experiments were carried out as a completely randomized design (CRD) with three replications in seed science & technology lab Tehran university, in 2012. Seeds were exposed to priming treatments, including hydropriming and urea priming (-4 and -6 bar), under two constant temperatures of 10 and 15oC, for 12 or 24hrs. Afterwards, primed seeds were examined for germination under two moisture conditions including optimum moisture and drought (-10 bar). Our results indicated that priming treatments improved most of germination attributes, particularly under drought conditions. In optimum moisture condition, the highest of germination index was due to 24hrs of hydro priming in 15oC and the lowest was observed in control. The highest germination index belonged to hydro and osmo priming (-4 and -6 bar) for 24 hrs under 15oC, and the lowest values belonged to which osmo primed at -4 bar, for 12 hrs under 10oC. Under the drought conditions, the highest germination percentage was observed in seed batches treated with urea osmo priming at -4 bar for 24 hrs under 15oC, and the lowest was observed in control condition. The best percentage, index of germination in both temperatures and all priming treatments occurred due to 24 hrs of each treatment. The highest vigor index belonged to 24hrs of urea osmo priming at -6 bar under 15oC.

Preharvest sprouting occurs in rainy and humid weather during milking to ripping periods that leads to loss of grain weight and reduction of Seed quality. Wheat is susceptible to Zn and Mn deficiency therefore. An experiment was conducted to evaluate effects of micro minerals on germination characteristics in different stages (ripping, dough development and milking). Grains harvested from different stages of ripping, dough development were planted in completely randomized design in Petri dish at 18±20oC in germination growth. Variables such as germination percent and uniformity of germination were evaluated on 7th day, variables including root and shoot length, root dry weight, shoot dry weight and seed dry weight. Data were analyzed using SAS software. Results showed that different harvest times were significant on percent germination, rate and uniformity of germination, and shoot length, root, shoot, waste seed and seed dry weight. Duration times of 5, 10, 50, 90 and 95% germinations were not significantly different between ripping and dough development but there were statistically different between ripping and milking stages. Correlation coefficient of variables showed that uniformity of germination with germination rate was significantly different but there was a significant negative correlation between rate of germination and dry weight of bomass. It seems that in ripping stage, endosperms of seeds were developed and supplied seed storage for germination. Generally, from dough development to ripping, there is possibility of preharvest sprouting in wheat farms.

In order to study the effects of seed inoculation with Plant Growth Promoting Rhizobacteria (PGPR) and nitrogen application time of on yield, rate and effective grain filling period of wheat (Triticum aestivum L.), a factorial experiment was conducted based on completely randomized block design with three replications in Research greenhouse of the Faculty of Agriculture, University of Mohaghegh Ardabili in 2011. The Factors were: nitrogen application timing in three levels (1/3 planting, 1/3 tillering stages, 1/3 before anthesis ), (1/4 at planting, 1/2 tillering and stem elongation stages, 1/4 at anthesis), (1/4 planting, 1/4 during emergance, 1/4 stem elongation, 1/4 at anthesis) as N1, N2 and N3 respectively and seed inoculation with plant growth promoting rhizobacteria in four levels containing (without seed inoculation as control, seed inoculation with Azotobacter chroococcum strain 5, Psedomunas strain 41, Psedomunas strain 186). Results showed that nitrogen application timing and seed inoculation with PGPR significantly affected all grain filling parameters. Maximum of grain weight and effective grain filling period were obtained in nitrogen application as N1´ seed inoculation with Azotobacter. Means comparison showed that grain per plant, number of grains per spike, weight of 100 seeds, plant height, spike length, root weight and protein percentage increased with nitrogen application as N1 and seed inoculation with PGPR. It seems that in order to increase of yield and yield components, rate and effective grain filling period can be suggested that seed inoculation with Azotobacter be applied in time of utilization of nitrogen as N1.

Lolium rigidum Gaudin. and L. prenne L. species, are two forage species from poaceae category that have high importance in terms of palatability and production of forage. In this investigation, a factorial experiment based on a completely randomized design with three replications was performed. various concentrations of NaCl were in 100, 200 and 300 mM for 24, 48 and 72 hours and distilled water was used as control .Subsequently Some, parameters were evaluated such as germination percentage (GP), germination rate (GR), germination value (GV) and germination index (GI) of Lolium rigidum Gaudin. and L. prenne L. The results showed that the effect of NaCl priming was significant (p£0.01) on GP, GV, GI and GR of two species. Therefore, priming application appreciably increased the germination characteristics and preliminary growth of two forage species. In addition, NaCl priming as a psychological treatment significantly increases the germination yield of two species seeds under salt stress.