Germination Test of Zinnia Seeds Under Salt Stress and Scanning Electronic Microscope Analysis

Abstract

Saline soils negatively affect seed germination. To determine the effect of different salt doses in the growing medium on seed germination, zinnia (Chrysogonum peruvianum L.)  seeds were treated with 0, 50, 100, and 150 mM NaCl. Zinnia seeds were sown in petri dishes, 20 seeds per dish, between filter paper. Salt doses of 0, 50, 100, and 150 mM were prepared and applied to each petri dish containing the seeds. The study was designed according to a randomized complete block design with 3 replications and 4 petri dishes in each replication. Daily germination data were collected from the petri dishes containing the zinnia seeds. Since the germination of the zinnia seeds was complete after 15 days, the study was terminated and analyses were performed. The study evaluated the responses of zinnia seeds to salt doses of 0, 50, 100, and 150 mM. It was observed that germination rate and germination index decreased with increasing salt doses, while germination days increased with increasing salt concentration. Scanning electron microscopy results showed the presence of C, O, Ca, Si, Na, S, and Cl elements in zinnia seeds at 0, 50, and 100 mM salt doses, while sulfur was not detected at 150 mM. It was also observed that increasing salt concentrations led to shrinkage and shriveling of the seed coats.