Iranian Journal of Seed Research

Seed coat color as a perfect and simple index is effective in water absorption, seed dormancy and germination. The mustard plant produces seeds with different coat color. So, in order to investigate the effect of seed coat color on germination rate, the percentage of germination and dormancy of Mustard (Sinapis arvensis L.) seeds an experiment was carried out based on a completely randomized design with four replications. Treatments were included two types of seed coat color (brown and black) and dormancy breaking treatments (Control, Potassium nitrate 0.2%, GA₃ 250, GA₃ 500 ppm and one, two and three weeks prechilling). The results showed that the differences between germination indices traits in brown and black seeds were significant. So that, the germination rate and germination percent in black seed were greater than brown seeds, but the duration of dormancy in brown seeds was greater than black seed. One week prechilling treatment had the most effect on breaking dormancy. So that germination percentage and germination rate for black seed was 75% and 0.54 respectively and these amounts for brown seeds were 58% and 0/43 respectively. Potassium nitrate and GA₃ (250 and 500 ppm) reduced germination rate and germination percent in both types of seeds. In addition, water absorption percent in brown seeds was more than black seeds. The final results showed that heteromorphic seeds of Mustard have variation in duration of dormancy, germination and water absorption percent.

Priming of seeds by magnetic fields (magneto priming) is proposed as an ecological, useful and low-priced method for improvement of seed germination and plant emergence. In order to evaluate the germination behavior of sesame seeds affected by magnetic fields, an experiment was conducted as a completely randomized design with 22 treatments (non-exposure to magnetic fields (control) and 21 magneto priming treatments) with three replications at the college of agriculture, the Ferdowsi University of Mashhad in 2014. the seed of sesame put into a plastic bag bulky and was treated with different intensity of magnetic fields (25, 50, 75 and 100 mT) for several times (10, 20, 30, 60 and 120 minutes). For assessment of germination traits of sesame under constant magnetic field conditions, magnetic tapes with three mT strength were used in each Petri dish throughout the experiment. Results showed that magnetic fields had no significant effects on final germination percentage and mean germination time and all magnetic treatments except for 75 mT at 60 minutes indicated reducing effects on germination percentage in comparison to control. Priming of seeds with magnetic fields in 50 mT strength for 20 minutes led to the increment of germination rate compared to control treatment but all levels of 100mT treatment caused a reduction in germination rate than control. The most radicle length, seedling length and seedling vigor length index belong to 75 mT at 60 minutes treatment and the most seedling dry weight and seedling vigor weight index related to 100 mT for 20 minutes treatment. Ranking of treatments showed that exposure of seeds for one hour in 75 mT and 10 minutes in 25 mT magnetic fields strength had the best outcomes.