Non-chemical treatments to improve the seeds germination and plantlets growth of sessile oak

Abstract

The current study aimed to investigate the effect of different treatments applied to sessile oak seeds in order to improve the germination features, development and growth of seedlings. The seeds were subjected to electric field, electromagnetic field and γ rays’ treatments. For the electric field study three distinct voltages (10V, 30V and 50V) and three values of exposure time (15 min., 35 min. and 60 min.) were considered. Displaying the seeds in an electric field for 60 minutes increased the germination rate with 58.89%. The highest value for the seedling’s height was obtained when seeds were exposed for 15 minutes at an intensity of 30V. The interaction between the intensity and the timing showed that treating seeds with 30V for 35 minutes improved significantly the seedlings peculiarities. In regard to the electromagnetic field, the seeds were subjected to a single value of electromagnetic field (B=0,4mT; i=0,680 A) and three values of exposure time: 10 min., 20 min. and 30 min. The sessile oak seeds subjected to the electromagnetic field for 20 minutes induced the highest value of germination percentage (90.00%) and germination index (1.81) and those seeds produced plantlets with high diameter (2.69 mm) and with significant differences towards non-treated plants. For γ rays treatments a dosage of 2 Gy induced the highest value of germination percentage (86.67%), of germination index (2.02); of germination energy (7.7); and of germination speed (7.24). A dosage of 6 Gy decreased the values of the same parameters. Our results showed that a dosage of 2 Gy improved also the growth parameters such as plantlets diameter (2.65 mm) and height (11.25 cm). In short, the physical treatments represent an ecological substitute approach towards the chemical substances presently used to improve seeds germination. Using physical treatments for seeds germination and growth of seedlings might be a harmless alternative for environment.