Iranian Journal of Seed Research

In order to investigate the effect of priming techniques on germination parameters of ajowan (Carum copticum L.) seed, an experiment was conducted in completely randomized design with four replications. The experiment treatments included a control (no priming), three hydropriming levels with distilled water (24, 36, and 48 h), three osmopriming levels with PEG (solutions with osmotic potential of -4, -8 and -12 bar), three hormone priming levels with GA3 (50, 100 and 150 ppm), three halopriming levels with KNO3 solution (2, 3, and 4%) and three zinc sulfate levels (0.1, 0.2 and 0.3 %). The results showed that priming treatments had a significant effect on all traits. The rate and percentage of germination were declined in some priming treatments compared to control. Radicle length and root dry weight were decreased in polyethylene glycol -8 bar. Polyethylene glycol -4 bar and 24h hydropriming treatments significantly decreased shoot length and allometry coefficient. However, the treatment of 100 ppm hormone priming significantly increased these traits. Hydropriming 24 h treatment significantly increased germination rate, percentage and seed vigor, but hydropriming 48 h significantly increased radicle and shoot length compared to control. In conclusion, according to the priority of germination or radicle, shoot growth and seed priming cost as well, the hydropriming 24 or 48 h can be recommended as most appropriate priming type for ajowan seeds.

Extended Abstract
Introduction: Priming is one of the most commonly used seed enhancement techniques. Events such as increased synthesis of nucleic acids, activation of repair processes, increased respiratory activity, and improved antioxidant capacity during priming lead to advanced metabolism in seeds. The most important effects of priming include increased percentage, speed and uniformity of germination and emergence. However, the longevity of primed seeds in storage is the major concern for researchers as it restricts widespread use of this technique. Some researchers believe that priming reduces the storage capacity of seeds, while others have reported increased seed shelf life after using priming treatments. Therefore, this study sought to investigate the effects of priming on the storage capacity of the seeds of canola cultivars under different storage conditions.
Material and Methods: In this study, the effects of priming on the shelf life of seeds of three canola cultivars including Dk-xpower, Traper and Hayola50 were investigated. For this purpose, the seeds were first treated with hydropriming and osmopriming methods. Then primed and control seeds with 6, 9, 12 and 15% moisture content were stored for 8 months at 15, 25, 35 and 45 °C. Sampling from different seed treatments was carried out at intervals of 1 to 30 days to assess germination. Finally, by fitting a three-parameter logistic model to cumulative germination data versus the day after storage, the time to germination loss to 50% was calculated and used to compare seed storage behavior between the treatments.
Results: The results showed that the storage behavior of canola seed varies greatly depending on the cultivar, and each cultivar showed a distinct behavior. Priming effects on the shelf life of seeds were different depending on the storage conditions, cultivars and also the priming methods. Comparison of the effects of priming on the seeds’ shelf life under different storage conditions showed that priming treatments were more efficient under higher seed moisture content and storage temperatures than those with lower seed moisture content and storage temperatures. In addition, priming treatments in Dk-xpower cultivar often increased the seeds’ shelf life. However, in the Traper and Hayola 50 cultivars, hydropriming often improved the seeds’ shelf life, and in contrast to osmopriming, it led to a decrease in the shelf life of the seeds.
Conclusion: Based on the results of this study, it was shown that priming effects on canola seed viability can be a function of various factors such as cultivar, storage conditions, and also the type of priming treatment. Moreover, in this study, hydropriming often increased seed longevity whereas osmopriming often increased the deterioration rate and reduced seed longevity.
 
 
Highlights:

1. Seed storage behavior of canola cultivars was compared under natural storage conditions.
2. Priming effects on seed longevity of canola cultivars was investigated under different storage conditions.

Extended Abstract
Introduction: Medicinal herbs are of particular importance in the treatment and prevention of diseases. Indian Cheese Maker has strengthening, liver repair, anti-inflammatory properties and is useful in the treatment of bronchitis, asthma, wounds, neurological disorders such as Parkinson's and Alzheimer's. Evaluation of seed quality as a propagating organ and the most important input for crop production and medicinal products has a special place in seed production, control and certification. Studying germination and biological properties of seeds of medicinal plants and methods of breaking dormancy in them are among basic and primary studies of domestication of medicinal plants. In the meantime, scrubbing with abrasives changes the integrity of the seed shell and allows the seeds to be permeable to water and gases. The researchers stated that the dormancy of seeds containing inhibitory metabolic materials can be reduced by removing the seed shell through mechanical scarification and osmopriming. For this purpose, the effect of scarification and potassium nitrate on germination and enzymatic properties of Indian Cheese Maker was evaluated.
Material and Method: This study was conducted as factorial based on a completely randomized design with three replications during 2015-16 at the laboratory of Department of Agronomy, Tarbiat Modares University. Potassium nitrate solution (0, 0.5, 1 and 1.5 mg.l^-1 from KNO₃), scarification (un-use and scarification with soft sanding) and osmopriming durations (8, 16, 24 and 32 hour) were experimental factors. The experiment was performed on Indian Cheese Maker seeds, landrace of Khash. Petri dishes were placed in a germinator at 25 ° C and in full lighting for 14 days. In this experiment, germination rate and percentage of germination, mean of germination time and daily germination, seed vigority, alpha and beta amylase were measured.
Results: The results of the experiment showed that in scarification, the highest germination percentage (69.47%) was obtained by seed priming at a concentration of 1.5 mg.l^-1 potassium nitrate for 19 hours under abrasion. In scarification, germination rate increased at 16 and 32 hour, 0.62 and 1.17 No.day^-1 for each mg.l^-1 of potassium nitrate. The highest daily mean germination (0.15) was observed at 1.5 mg.l^-1 potassium nitrate and 24 hour time and decreased to 8 hours mean germination time (7.39 days) by reducing pretreatment time. Also, the highest mean germination time (9.35 days) was observed in 32 hours pretreatment with potassium nitrate and the highest mean germination time in non-scarification condition (9.13 days) and in scarification condition decreased with mean of germination time (8.04 days). The activity of alpha and beta-amylase germination enzymes was affected by different concentrations of potassium nitrate and scarification and at high concentrations of potassium nitrate the activity of these enzymes decreased.
Conclusions: In general, application of potassium nitrate osmopriming, by improving the activity of germination enzymes and increasing seed germination properties of Indian Cheese Maker, increased the activity of hydrolyzing enzymes in the endosperm of germinated seeds, which reduced the mean germination time, increased germination rate and germination percentage. In general, seed scarification with low concentrations of potassium nitrate at 16 to 24 hours is recommended for breaking seed dormancy of Indian Cheese Maker.

 
Highlights:

1. Germination rate and percentage of Indian Cheese Maker seed were monitored by osmopriming and scarification.
2. The role of α and β amylase germination enzymes in accelerating dormancy breaking of Indian Cheese Maker was studied.
3. Mean time and mean daily germination during the dormancy breaking process of Indian Cheese Maker were estimated.

Extended Abstract
Introduction: Iranian oak has the largest forest habitat in the country and has a high position in terms of economy and protection. Recent studies have confirmed the positive effects of carbon nanotubes on the germination and organ growth of herbaceous and woody species. Nanotechnology is an evolving field in all periods of human life and various research is done to use nanomaterials in different fields. Nanotechnology can provide a good medium for the production of plants with suitable characteristics or provide better growth conditions for plants. The aim of this study was to investigate the effect of carbon nanotube treatments, calcium chloride 1% and potassium nitrate 1% on the germination traits of Iranian oak seed (Quercus brantii Lindl).
Materials and Methods: Treatments included carbon nanotubes at five levels (concentrations of 10, 25, 50, 75, and 100 mg/l) for six hours, 1% calcium chloride for 48 hours, potassium nitrate for hours 24 hours and control treatment, which were primed without using any materials and germination traits were tested on them.
Results: According to the results, carbon nanotubes affected germination traits, so that Iranian oak seeds at a concentration of 75 mg/l had the highest germination percentage and rate, and primed seeds with a concentration of 100 mg/l had the highest mean germination time. The lowest germination percentage, speed and mean germination time were related to control seeds.
Conclusion: The results showed that carbon nanotubes with 75 mg/l had the most positive effect on germination traits. Therefore, from an economic point of view, the use of this concentration is recommended for priming oak seeds.

Highlights: