Effects of Low-Temperature Plasma Treatment on Germination, Seedling Development, and Biochemical Parameters of Long-Term-Stored Seeds

The promising field of low-temperature plasma treatment, known for its non-invasive and environmentally sustainable nature, is being actively investigated for its ability to enhance germination, emergence, yield, and overall plant development in a broad spectrum of crops. For gene bank requirements, low-temperature plasma technologies can also improve germination parameters and promote the development seeds suitable for long-term storage. Seeds from four selected cultivars of wheat, oats, flax, and rapeseed stored in the gene bank for 1, 10, and 20 years were subjected to plasma treatments for 20, 25, and 30 min. The study evaluated the mean root and shoot length, root–shoot ratio, and seedling vigour index. Additionally, the malondialdehyde level, total polyphenol content, total flavonoid content, and total antioxidant capacity were analysed. Plasma treatment displayed varying effects on the morphological characteristics and antioxidant activity of the tested cultivars, which were influenced by treatment duration and cultivar. A positive effect of plasma treatment on seedling length, seedling vigour index, and root–shoot ratio was observed in flax cultivar ‘N-9/62/K3/B’ in all periods and in variants T2 and T3. Conversely, the wheat cultivar ‘Granny’ showed variable results, and the oat cultivar ‘Risto’ showed variable negative results in regards to mean root length and mean shoot length after plasma treatment. The indicators of oxidative stress and antioxidant capacity were affected in all the cultivars studied. A positive effect of plasma treatment on these indicators was observed in the wheat cultivar ‘Granny’, while flax cultivar ‘N-9/62/K3/B’ exhibited inconsistent results. While in cereals, a decrease in malondialdehyde content after plasma treatment was associated with an increase in polyphenol and flavonoid content as the treatment duration increased, small-seeded species responded somewhat differently. The rapeseed cultivar ‘Skrivenskij’ and flax cultivar ‘N-9/62/K3/B’ showed an increase in polyphenol and flavonoid content following a decrease in malondialdehyde levels. This study highlights the potential of low-temperature plasma treatment for long-term-stored seeds and its applicability to plant genetic resources. The findings emphasize the need for the further optimization of low-temperature plasma treatment conditions for different plant species and cultivars.