EFFECT OF LOW-PRESSURE PLASMA TREATMENT ON THE SEED SURFACE STRUCTURE OF Desmanthus virgatus L. WILLD.

Abstract

Low-pressure argon plasma at a controlled temperature of 40 ºC was used to overcome seed dormancy in Desmanthus virgatus (L.) Willd. Treatment times were 1, 3, and 5 minutes. Infrared analysis confirmed the presence of lipids, proteins, and carbohydrates without the formation of new functional groups. The low-pressure controlled environment and the inert gas plasma changed the intensity of polar and nonpolar groups present on the seed surface. These changes directly influenced the water absorption tests because all treated seeds germinated after 24, 36, and 312 hours in the treatments of one, three, and five minutes, respectively. Germination did not occur among untreated seeds, proving the effectiveness of plasma in overcoming dormancy. The pH and conductivity results showed that plasma treatment resulted in faster germination and lower nutrient release to the medium. In addition, the seeds treated for one and three minutes showed superior results for the germination potential, germination rate, and germination index, demonstrating the effectiveness of low-pressure plasma as a clean technique and an alternative tool for reducing environmental impacts in the surface modification of D. virgatus L. Willd seeds.

Keywords: Argon plasma; Germination; Physical dormancy