نشریه علوم و فناوری بذر ایران
سال نهم شماره 3 (پیاپی 19، پاییز 1399)

This experiment was conducted in a factorial arrangement in a completely randomized design with three replications. 24 canola genotypes (13 varieties and 11 double haploid lines) at four levels of soil moisture including 80, 50, 30 and 20% field capacity (FC) were evaluated in pots in the greenhouse of seed and plant improvement Institute in Karaj during 2017. The growth of the shoot was more affected by different levels of soil moisture in comparison to the root growth that indicating a greater sensitivity of the stem length compared to the root length in response to the low water stress. Therefore, the root-shoot ratio can be an appropriate index for assessing the water stress tolerance. The results showed that cultivars such as Oase, Triangle, Tassilo and Savanah, had very high stability under stress conditions, but due to small amounts of the first and second components, they were classified as susceptible to water deficit stress. Also, SLM046 and Billy had the least stability in traits under water deficit stress at germination stage. Due to the non-separation of the three levels of soil moisture (80%, 50% and 30% FC), were not suitable for selection and only 20% FC was identified as the appropriate condition for selecting the ideal genotype. Therefore, between genotypes that were located in a 20% FC, based on the 'which-won-where' pattern, GKH 2005 was identified as the superior genotype.

In order to evaluate germination characteristics and shelf life of alfalfa seeds stored in different storage conditions, a factorial experiment was conducted in a completely randomized design in a graduate laboratory of Urmia University of Agriculture. The experiments included relative humidity in six levels (50, 60, 70, 80 and 90 %) and control (room humidity) and storage duration (0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 months) with three replications. The studied traits included germination indices, seedling growth indices, and seed vigor and storage capability of seeds. The results showed that all germination indices were affected by relative humidity and storage duration. The interaction between moisture and storage duration was significant except for germination uniformity on all indices. The highest germination percentage was obtained in the control conditions (96.9 %), which reached 79.4 after 10 months of storage. Increasing the moisture content of the storage caused a significant decrease in the coefficient and uniformity of germination. The germination rate was the highest in the first month with the average of 0.071 per day, which had the lowest in 90 % relative humidity in the 10 months after storage to the average of 0.018 germs per day.

Two separate experiments was arranged in a randomized complete design in 4 replicates in order to evaluate agronomy aspects of cultivation and aim of evaluation effective treatments in breaking dormancy of native and valuable medicinal plant, Caper seeds (Mazdavand ecotype) and also to evaluate the best seed bed medium for germination of Caper seeds along with sustainable agricultural systems. Treatments in breaking dormancy test included control (distilled water), pre chilling (for 2 and 3 months), GA3 (250 and 500 ppm for 12 hours), KNO3 (0.2 and 0.5% for 12 hours), scarification with sandpaper (85%), seed coat removal, soaking in NaClO 0.5% for 5 minutes, scarification+250 ppm GA3, scarification+0.2% KNO3, scarification+250ppm GA3+0.2%KNO3. Treatments in evaluation the best seed bed medium experiment included control (soil of habitat), manure fertilizer, vermicompost and bio-fertilizer (phosphonitrokara). According to results of first examination, pre-chilling for 2 and 3 months were the best treatments for breaking dormancy (with 85% germination and 3.5 seeds per day germination rate). Also, results of evaluation the seed bed medium, showed that vermicompost had the highest germination percentage, highest number of leaves and the most seedling weight vigor index. Vermicompost and manure fertilizer had the highest leaf length, shoot length and seedling dry weight. Manure fertilizer and vermicompost, while creating sustainable agricultural conditions, increased the growth and improved morphological characteristics of the Caper medicinal plant seedlings.

Reducing the minituber dormancy has economic importance . The current study was aimed to find the best dormancy breaking treatment to reduce minituber dormancy of two commercial varieties (Sante and Agria). Since minituber dormancy period depends on different factors, the individual effects of treatments i.e. GA3 (0.05 and 0.07gl-1), thiourea (10 and 20gl-1) and CS2 (25 and 50mlm-3), genotype background (different dormancy periods), and minituber size (1.5, 2.5 and 3.5cm), were evaluated on minituber dormancy period. In addition to dormancy period, the effect of mentioned factors were investigated on sprout numbers and sprout length. Results showed that although CS2 and thiourea had good effects on the reduction of minituber dormancy, the detailed consideration of derived sprouts showed that it cannot be introduced as an appropriate dormancy breaking treatment. According to the results, GA3 (0.05gl-1) was found to be the best treatment for reducing dormancy period in both cultivars. GA3 (0.05gl-1), in addition to break the dormancy of different minituber sizes of both cultivars, had good effect on sprouting related parameters of treated minitubers.

Safflower (Carthamus tinctorius L.) is an important industrial plant, which classified in the category of oil plants. The tolerance of plants to drought is different, as well as Plants have different temperature and water requirements, and understanding this requirement helps them survive and reproduce. Therefore, the purpose of this study was to evaluate the germination characteristics of safflower seeds at different temperatures and humidity and the adaptation power of this plant under these conditions. For this purpose, germination of safflower seed (Faraman cultivar) was investigated in incubator at constant temperatures of 5, 10, 15, 20, 25, 30, 35 and 40 ° C. in this study, 3 regression model including, Beta model, Dent like model and segmented model were used to determine cardinal safflower temperatures. Then, to investigate germination and seedling growth response of Carthamus tinctorius toward different levels of Water Deficite Stress at an optimum temperature, another test was conducted. in this experiment, seed germination was assessed in six levels of Water Deficite Stress with the osmotic potential of 0, -3, - 5, -7 and -9 bar (in temperatures of 20 ° C). Based on Beta model, Dent like model and segmented model, the cardinal temperatures of Carthamus tinctorius seeds germination including, (Tbase, Topt and Tmax) were: (4.6, 4.1, 4.1), (22.02, 20 – 24.3, 22.5) and (43.3, 50.3, 50.3) °C, respectively.

In order to investigate the effect of drought stress on germination parameters and heterotrophic growth of different wheat cultivars, a factorial experiment was carried out in a completely randomized design with 6 replications in a research greenhouse of Faculty of Agriculture and Natural Resources, University of Gonbad-e- Kavous in 2016-2017 .The treatments were included wheat cultivars in 5 levels (Aftab, Qaboos, Kohdasht, Karim and Line 17) and drought stress in four levels (full irrigation as the control, slight water stress (25% water depletion of field capacity) , intensive water stress (50% water depletion of field capacity) and very intensive water stress (75% water depletion of field capacity). The results of this experiment showed that maternal drought stress was significant only on radicle dry weight, plumule dry weight and seed vigor. There was a significant positive correlation between plumule dry weight, plumule length and seed vigor. It can be said that drought stress can greatly affect the seed vigor of different wheat cultivars. So that seed vigor of different cultivars was different at each stress level. The effect of cultivar was significant on all traits except radicle dry weight. Therefore, germination and seedling growth were more affected by cultivars. Regarding the negligible effect of drought stress on most germination traits, it can be concluded that genetic than environment (maternal drought stress) had a more effective effect on germination and heterotrophic characteristics of seedlings of wheat seeds

In order to quantify the seed germination responses of Fennel ecotypes including Esfahan, Hamadan and Booshehr to osmotic stress with concentrations of (0, -0.1, -0.2, -0.3, -0.4 and -0.5 MPa) a factorial experiment was conducted based on the completely randomized design with four replications. Experimental data were subjected to analysis with various statistical distributions to provide more reliable and robust explorations. RSME value of hydrotime model showed that data were well fitted for seed germination of Booshehr. The normal and Gumbel distributions were the best and the worst model to estimate hydrotime model parameters. It was also cleared that among statistical distributions fitted on hydrotime model, the highest base water potential was obtained from Normal distribution -0.41 MPa. For Esfahan ecotype, hydrotime constant was estimated about 89 MPa/hour using Gumbel distribution. There was significant variation in location parameters of various statistical distributions and it has a range of -19.44 (Weibull) to -0.57 (Normal Distributions).

Rice (Oryza sativa L.) is a staple food for more than half of the world's population. Globally, rice is grown on 161 million hectares, with an average annual production of 678.7 million tonnes. Germination is one of the important stage in rice life. In order to investigate the relationships among AFLP markers and germination traits in rice plants, 192 Rice lines were evaluated. Lines were used in the form of an augument design with 100 seeds per line. The purpose of this study was to identify linked markers for gene controlling plumule length, root length, coleoptile length and germination percentage. 21 primer combinations of EcoRI and MseI a total of 376 bands were produced, of which, 303 bands were polymorphic and had an average of 75.03 percent polymorphism. The most variation in plumule length were determined by E080-M140-11 (19.55%), E060-M160-11 (17.92%) and E080-M150-11 (17.87%).060-M160-11, E080-M150-11, E110-M150-8 and E120-M150-5 Markers were associated with both shoot and root length, which represents an extremely close association of the traits together, or possibly are affected multi-effect genes. Using linked markers with germination traits in this study, we can use markers to help them improve them.

This study evaluated different methods of improving seed germination in date palm (Phoenix dactylifera L.) of Medjool cultivar. The experiment was laid out in a completely randomized design and each treatment was replicated four times. Treatments were consisting of distilled water for 24 h at ambient temperature, potassium nitrate (KNO3) at 0.5 and 1% for 24 h, sulphuric acid (50% H2SO4) for 3 min, sulphuric acid (98% H2SO4) for 3, 5 and 10 min, boiling water for 5 and 10 min and control(seeds were not treated). The best seed germination and seedling growth were obtained in seed soaking treatments in distilled water and potassium nitrate. The greatest percentage and speed germination was observed in treatment of potassium nitrate (KNO3) at 0.5 % for 24 h. The seeds treated with boiling water for 5 and 10 min and sulphuric acid (98% H2SO4) for 3, 5 and 10 min, did not germinate at all. The lowest Mean time to germination was obtained in distilled water for 24h that had no significant difference with distilled water for 48h, potassium nitrate (0.5 and 1%) for 24h. The highest fresh and dry weight of stem was observed in distilled water for 48 h treatment. The greatest root length was related to control, distilled water (48h) and potassium nitrate (1%) treatments. There was no significant difference between the treatments in shoot height. Therefore, pre-treatment of seeds with distilled water or potassium nitrate effective way to improve seed germination of date palm.

This study was set up to survey the possibility of mulch utilization in water use management and to evaluate its effect on quality and quantity of potato seed tubers. A split plot factorial experiment based on randomized complete block design with 3 replications was conducted in 2 locations (Ardabil and Esfahan) and at 2 years (2013-14 and 2014-15). Main factor was Irrigation regime (Control and Mild Drought Stress) and sub factors were Variety (Agria, Arinda and Sante) and Mulch (Control, Wood chips, Straw and Compost of municipal waste). Results showed that under Mild drought stress, mulch (especially straw) significantly increased tuber number per unit area, while did not affect yield. Mild drought stress significantly reduced the number of established plants of Agria cv., hence straw mulch significantly increased established plants number of this cultivar under drought stress. Mild drought stress significantly reduced tuber size in Arinda cv. and straw or wood chips mulch significantly increased tuber size of this cultivar under drought stress. Organic mulch significantly increased soil organic carbon while compost of municipal waste decreased the amount of soil organic carbon by 17.1 percent