نشریه علوم و تحقیقات بذر ایران
سال سوم شماره 2 (تابستان 1395)

In this study investigated the effects of seed quality on germination parameters and heterotrophic seedling growth in two maize varieties including single cross 640 and 704. For seed deterioration treatments we used accelerated aging test in 410C for 24, 48, 72 and 96 h. A factorial experiment in a completely randomized design with four replications was conducted in the laboratory. Results showed that the seed deterioration effects on all traits studied included speed germination, germination percent, germination uniformity, normal seedling percent, plomule length, allometric growth ratio and seedling length vigor index were significant for but there was no significant effect on heterotrophic seedling growth traits. The varieties also have significant effects at 1% level on all the traits except allometric growth ratio, final seed and root dry weight. Seed deterioration had no significant effects on shoot length, allometric growth ratio, seedling length vigor index in 704 and on germination growth rate in 640. With increasing of seed deterioration were decreased germination percent and uniformity. Seed deterioration was more intense on seed germination percent in 640. Heterotrophic growth parameters such as seed reserves use efficiency, fraction of seed reserves mobilization and final seed dry weight has higher averages to larger cotyledon in 640. At the end of the day increasing the seed aging caused decreases on germination and normal seedlings percentage in both varieties but 704 was more resistant to decay.

In order to study of genetic diversity chicory ecotypes in drought stress condition via multivariate analysis an experiment was preformed in factorial form using a completely randomized design with 3 replications at Islamic Azad university, Ahvaz branch in 2013. First factor incompasis 26 chicory ecotypes and second factor five levels of drought treatment (0 ,-2 ,-4 ,-6 and -8 bar), were used by using PEG 6000. Traits germaination percent, germination rate, mean of germination time, radicle length, plumule length, seedling length, radicle/plumule length ratio, wet weight of seedling, dry weight of seedling, wet/dry weight ratio and seed vigor index were studied. Results analysis of variance showed that between ecotypes, drought stress and their interaction for all trait, had siginificant difference. The most positive and significant correlation was between the seeding length and root length. The principal components analysis, 11 studied traits divided to 3 components and according to which 79% of the total variation to be justified. In biplot graphic method to basis the first and second components and cluster analysis; ecotypes of third cluster incompasis 36546, 2398, 15008 and 15084 according to all traits better than of other ecotypes were, therefore this ecotypes compare to other ecotypes tolerance to drough. Based on results of this study, use of this ecotypes for future breeding programs tolerance to drought can be recommended.

To study the efficiency of three priming methods to increase salt and drought stress resistant of safflower in germination and early growth, a laboratory experiment was conducted as factorial arranged in completely randomized design with four replications in seed laboratory of Iranian Plant Protection Research Institute. First factor was kind of stress include salt and drought stress, second factor was priming method include hydropriming (treated with water for 6 h), Halopriming (treated with NaCl 100 mM), KNO3 (0.5%) and no priming as control and third factor was water potential include 0.0, -0.3, -0.6, -0.9 and -1.2 MPa. Too, salt and drought conditions caused by NaCl and PEG respectively. Results showed that both stresses inhibited water uptake, germination percentage, radicle and Plumule length and seedling vigour index, but this criteria significantly were higher in NaCl than PEG at the same water potential. All of three used priming treatments increased germination and seedling growth under salt and drought stresses. By increase of stress intensity, efficiency of priming methods increased too. Hydropriming was more effective than other priming to decrease salt and drought damage in germination and early growth stages and it is suitable and low cost strategy.

Some phytochemical compounds medicinal plants as allelopathic compounds added thephenomenainvolved, germination, growth and reproduction of other plants are affected Thatis whyin recent years the use of allelopathy in weed management has attracted the attention of manyexperts. To evaluate the effect of aqueous extract of Echinacea angustifolia and Lallemantia royleanaon seed germination and seedling growth indices of Sinapis arvensis and Avena fatua factorial experiment in a completely randomized design with 3 replications, in 2015 the Faculty of Agriculture in seed technology laboratory control done .The experiment consisted of two aqueous extract (Lallemantia royleana and Echinacea angustifolia) and two seed (Sinapis arvensis and Avena fatua) and fourecon centrations (control,5, 10and 20 percent). Germination percentage, germination rate, seedling length and seedling dry weight were determined.The results showed that the effect ofaqueous extract ofthe plant treated and different concentrations of aqueous extracts on the germination percentage , germination rate,seedling length and seedling dry weight was significantat thelevel ofone percent The results showed that all concentrations of aqueous extract of Lallemantia royleana to Echinacea angusti folia seed germination percentage and speed, seedling length and seedling dry weight Sinapis arvensis and Avena fatua have a deterrent effect, so thatby increasing the concentration of the extract, the inhibition rate increase the increase was greater for Sinapis arvensis to Avena fatua.

This study was conducted to grouping of 10 genotypes of canola via ISSR and IRAP markers and genotype resistance to drought. Eighty five polymorphic bands were produced using 19 individuals and combinations of ISSR and IRAP, and polymorphism varied between 50 to 100. Cluster analysis with UPGMA method placed the 10 genotypes in tree cluster, which includes 5, 3 and 2 respectively. Cluster analysis of germination results based on Euclidean distance with UPGMA method assigned treatment in four different groups consists of 11, 5, 9, and 15 genotypes respectively. Fisher’s linear Discriminant Function Analysis confirmed validity clustering analysis with 95%. The second group had the highest value, for most economical traits. SLM046 genotype could be introduced as resistant genotype by placing different treatments of its in one group. The fourth group included genotypes that had low value for most characteristics. Factor analysis results based on principal components showed that three factors named plumule, radicle and germination percentage, which determined 88.31 percent of total variation. First region was detected as good region on the base first and second factor evaluation. Genotypes in this area were favorable response to drought stress and could be introduced as resistant genotype at germination stage.

Ethylene is involved in many developmental and processes including plant senescence. Senescence is the final step of plant development resulting in death of plants. 1-aminocyclopropane 1-carboxylic acid) ACC) is produced in the last step of the ethylene biosynthesis. The Morphological characteristics of treated plants by ACC induce a phenotype called triple response including root and hypocotyl shortness and thickness. The occurrence of these symptoms indicates that plant system sense ethylene and its biosynthesis is activate. In this project, we examined the response of the wild type seedlings Ler-0, Col-0 and several mutants including old-3, old-9, old-14, etr1-3 and ko-5 to various concentration of ACC in Arabidopsis thaliana following evaluation of triple response characteristics. OLD genes in Arabidopsis are known as senescence involved genes. According to the obtained results, it shown that with increasing ACC concentrations, the triple response has been detected in most mutants, while in mutant etr1-3 none of those responses were observed meaning that etr1-3 is not able to sense and signal ethylene. These results suggest that change in OLD9, OLD3 and OLD14 function doesnt cause any significant impact on ethylene biosynthesis and signaling, while change in gene activity ETR in Arabidopsis led to the loss of the triple response in etr-3 plants. Thus, the genes controlling ethylene biosynthesis is different from genes regulating plant senescence.

This experiment carried out in order to investigate the effect of seed coating with growth promoting bacteria (Azotobacter and Pseudomonas) and micronutrients (Zn, B, Mo, Cu, Fe and Mn) on germination characteristics of corn (Zea mays L. SC. 640) . Experiment was conducted as complete randomized design (CRD) with four replications at agronomy laboratory in faculty of Agricultural Science, University of Guilan in July 2014. Experimental Treatments in this research were including seed without coating, seed coating without bacteria and micronutrients, seed coating with micronutrients and without bacteria, seed coating with (Pseudomonas fluorescens strain 169) and without micronutrients, seed coating with Pseudomonas and micronutrients, seed coating with (Azotobacter chroococcum strain 12) and without micronutrients, seed coating with Azotobacter and micronutrients, seed coating with (Azotobacter and Pseudomonas) and without micronutrients, seed coating with (Azotobacter and Pseudomonas) and micronutrients. Traits that were studied including: percentage germination, rate germination, radicule length, plumule length, radicule fresh weight, plumule fresh weight, radicule dry weight , plumule dry weight, Water absorption rate, uniformity of germination and Alpha amylase activity. The results obtained showed that seed coating with a mixture of Pseudomonas and Azotobacter and micro-nutrients and seed coating with Pseudomonas and micro-nutrients had the highest of content in most of the traits between investigated treatments.

Heavy metals of biosphere rise since the beginning industrial revolution and the toxicity of heavy metals cause to impair in the process of germination and growth of plants. In order to evaluate the effects of heavy metals on the germination of pinto bean (cv. Sadri) an experiment was conducted at Seed Technology Laboratory of Yasouj University in 2013. The experiment was conducted as CRD in five replications include different concentration of Cd(NO3)2, Pb(NO3)2, Ni(NO3)2 and CuSO4 (25, 50, 75 and 100 mg/l) and a control treatment. Germination characteristics include the rate and percentage of germination, seedling weight and length and seed vigor index were studied .Results showed that the highest rate and percentage of germination was belonged to control, and least in the 100 mg/l of Pb(NO3)2. With the increase in concentrations of Pb, percentage and rate of germination and root and shoot dry weight showed a downward trend. 100 mg/l concentration of Cadmium nitrate decreased the rate germination of pinto bean seeds in compare with control. Increasing the concentration of cadmium impairs the growth of seedling root; shoot and vigor index of bean. Toxic concentration of copper compared to nickel had more negative effect on germination, root and shoot length, root and shoot dry weight and seedling vigor. In general, the results of this study showed that cadmium and Pb may give to plants allows germination, but increased in their concentration impaired the some seed germination indices of pinto been seed.

In order to evaluate effect of time period of hormone and hydro priming on Stevia seed germination indices under salt stress a factorial experiment based on completely randomized design (CRD) with three replications was conducted in Seed Science and Technology Laboratory of Shahed University of Tehran in 2015. The studied factors consisted of seed pre-treating by gibberellic acid and distilled water for 0, 16, 24 and 48 hours and salt stress (2.5, 5, 7.5 and 10 dS.m-1). Germination percentage and speed, mean time of germination, mean of daily germination, daily germination speed and germination value was measured. Results showed that salinity× hormone priming interaction significantly influenced germination percentage and germination speed, mean daily germination and germination value. The highest germination percentage and germination speed was seen in 5 dS.m-1 and 48 hours hormone priming interaction and 2.5 dS.m-1 and 48 hours hormone priming interaction respectively. The highest daily germination speeds was seen in 0 dS.m-1 and 16 hours hydro priming interaction and 0 dS.m-1 and 16 and 24 hours hormone priming interaction respectively. Hormone priming of stevia seed by gibberellic acid for 24 and 48 hours could improve stevia seed germination parameters. Some of germination parameters (rate and percentage of germination) were reduced by salinity stress.