English

Abstract

Magnetic field is considered a simple and cheap method for stimulation of germination process compared to traditional chemical processes. In this research, laboratory experiment was conducted at Seed Technology Unit, Mansoura, Egypt to evaluate the effect of magnetic field on germination, seedling growth and cytogenetic characters of fresh and carry over (old) onion seeds (c.v.Giza Red). Seeds were magnetically pretreated by different magnetic field (0.03 or 0.06 T) using static magnetic device for different periods time (30, 60 and 90 mint). The obtained results indicated that magnetic field treatment increased all germination and seedling growth characters compared with control. Exposed fresh and carry over seeds to 0.06 T with 30 mint gave the heights values of germination percentage, germination rate, speed germination index and seedling growth parameters, that is, seedling length, seedling dry weight, seedling vigor I and seedling vigor II. Whereas, mean germination time was decreased using 0.03 T with 60 mint gave maximum values in carry over seeds and with 60 min in new seeds. Also, the results showed significant increase in mitotic activity and chromosomal aberration after 30 min treatments for both doses of fresh seeds and with 0.06 T of carry over seeds, while relative division rate (RDR) gave positive values and little disturbance in mitotic phase index. However, the percentage of mitotic abnormalities increased after all exposure treatments. It could be concluded that utilization of magnetic field could enhancement of germination of onion seeds but we need to be carry out more experiments to make magnetic map for all varieties of onion. Key words: Magnetic field, germination, mitotic activity, phase index, relative division rate, mitotic aberrations.