نشریه تحقیقات بذر
پیاپی 43 (تابستان 1401)

In order to study the allelopathic effect of safflower genotypes on germination and seedling growth characteristics of some weed species, a factorial experiment was conducted as a randomized complete block design with 3 replications in 2017 in the research laboratory of the Faculty of Agriculture, Azad University, Sanandaj branch. The first factor included three genotypes of safflower (Wild, Sina, and Kurdistan local) and the second factor consisted of four species of weeds (grass pea, millet, berseem clover, rye-grass) and the third factor includes safflower root extract in four concentrations (0: distilled water- control, 25, 50, and 100 percent) were considered. The studied traits in this experiment included: germination speed, root length, shoot length, root fresh weight, shoot fresh weight and seed vigor. The results showed that the studied traits showed significant differences under the influence of genotype except the length of root and seed vigor. Also, all investigated traits except root length were significant under the effect of root extract concentration and weed. The results of interaction effects were also significant for most of the investigated traits. In this experiment, the Sina genotype was superior in terms of its effect on reducing the rate of germination and seedling growth, and increasing the concentration of safflower root extract reduced the rate of germination and seedling growth. Also, berseem clover and grass pea, were identified as the most sensitive and resistant plants to safflower allelopathy, respectively.

Heavy metals of biosphere rise since the beginning of industrial revolution and the toxicity of heavy metals cause to impair in the process of germination and growth of plants. In this study the effects of different concentrations of Pb(NO3)2 (0, 50, 100 and 150 ppm), different concentrations of Cd(NO3)2 (0, 50, 100 and 150 mg/kg), different concentrations of Ni(NO3)2 (0, 50, 100 and 150 ppm)on germination were investigated in the independent experiments according to a completely randomized design with four replications. The results of ANOVA in three experiment indicated a significant difference between different treatments at a level of 1% for most traits.The result indicated that with the increase in concentrations of Pb, radicle and plumule length, radicle and plumule dry and fresh weight, vigor index showed a downward trend.Increasing the concentration of cadmium impairs the growth of radicle and plumule length, radicle and plumule dry and fresh weight, vigor index of radish. Also, with increasing the concentration of Ni(NO3)2 the most traits were decreased. In general, the results of this study showed that although Cd, Ni and Pb may allow germination, they impaired seed germination indices of radish.

Germination and seedling establishment are critical and important stages in the life cycle of plants. Therefore, the study of germination and methods of breaking on seed dormancy in plants is of great importance. One of the corrective operations on improving the seed yield of rangeland plants is seed priming. Priming is an operation on the seed that causes the seed to absorb a sufficient amount of water to accelerate the germination process. Trifolium resupinatum is a clover. In this study, in order to germinate seeds from treatments of 100, 200 and 300 mM sodium chloride in 24, 48 and 72 hours, gibberellic acid 125 and 250 ppm during 12, 24 and 48 hours and 0.01 solution, 0.02 and 0.03% of potassium nitrate were used for 12 and 24 hours, respectively. Distilled water was also considered as a control treatment. The study was conducted in a randomized statistical design with 3 replications and two-way analysis of variance was used to analyze the data. Traits such as germination percentage, germination rate, germination index, shoot length, root length, number of germinated seeds, seedling length and seed vigor index were evaluated. The results showed that in the seed germination of Iranian clover species, three chemical treatments had better results in terms of yield of the germination process of the species than other treatments and were recommended as the most desirable pretreatments and potassium nitrate and then acid treatments. Gibberellins had the greatest effect on the seed Dormancy breaking.

Melisa officinalis L. or Lemon balm; is belonged to Lamiaceae family is one of the most importan p;ant medicinal. The therapeutics effects of Lemon balm such as, antispasmodic and digestive effects have been demonstrated. Due to low small size of seeds, seed germination and fallow it primary growth will be affected. Seed used in this research were purchased from Pakban Company, Ispahan, Iran and then were surface sterilized in 1 % chloramineT for 3 min. Potato dextrose agar (PDA) medium was used for seed germination assay. The effect of tow cytokinin and gibberllic acid hormones at concentration of 50 and 100 mM in single and combination form was investigated in a factorial based on completely randomized design. Growth seedling were cultured and growth under pot culture containing peat moss and then some characteristics including germinated seeds, vigor index, seedling dry weigh, seedling length and coleoptile length were measured. Mean comparison analysis showed all used treatments have a significant effect at the level of 1% among tested parameters. The highest effect of treatment on seed germination was related to two hormones combination at 100 mM concentration and the lowes effect was recorded in Cytikinin application at 50 mM concentration. Our observation did not show any significant different and effect of culture medium on seed germination in compared to sterile water. Based on obtained data in this research, use of plant hormones at low concentration and in combination form is suggested to seed germination improvement and increase of growth parameters.

Different seeds deteriorate after harvesting and during seed storage, and this deterioration of seeds will cause a decrease in seed quality, seedling establishment and eventually decrease in plant yield in the field. To predict the longevity of orthodox seeds, the longevity equation  p v  Ki  is used, and this model can be used to compare the longevity of different cultivars, investigate the effect of different treatments or types of packaging on seed longevity, and also be used in the gene bank, etc. This model is not well known among Iranian researchers. In this study, the seed viability model has been introduced. In order to introduce the seed viability model, the germination data of mountain rye seeds in different storage conditions were used. ν is the probit based on the probit after storage, Ki is the initial probit of the seed mass, p is the daily storage period and σ is the standard deviation of the seed death distribution per unit of time. Another component of this equation is the relation log10σ = KE-CWlog10m-CHt-CQt 2 , where σ can be calculated from the relation σ=10(KE-CW log10m-CHt-CQt2). KE, CW, CH and CQ are constant coefficients of seed longevity, which CW coefficient shows the relative effect of seed moisture content, CH and CQ the response of seeds to temperature during storage, and KE the potential coefficient of seed lifespan. These coefficients can be calculated with a series of storage experiments with a wide range of temperature and seed moisture content. A larger KE in comparison between seeds indicates a longer longevity.

Food security and sustainable production have always been one of the main concerns of policymakers in governments. Due to the increasing world population and more demand for agricultural products, the importance of achieving food security and agricultural independence is increasing day by day. Application of new findings of research centers, academic institutions and knowledge-based agricultural technologies of the country, in addition to increasing the production of agricultural products, it reduces the cost of production and makes it more economical. Healthy and modified seed is one of the most important factors of agricultural production which has a direct and indirect effect on increasing performance by being resistant, ecological compatibility, increasing the consumption efficiency of production inputs and the possibility of using more of some inputs is effective. Therefore, healthy, genuine and high-quality seeds are one of the important pillars of production and development of the agricultural sector and moving in this direction increases the productivity of production resources, achieving food security and ultimately the independence of the country. Cite this article: Mirzaei Heydari, M., Bagheri, M. (2022). Seed producti