Screening of Tyumen-Bred Oat Genotypes for Resistance to Soda Salinity at Early Developmental Stages

This study aimed to identify oat (Avena sativa L.) genotypes developed within the Tyumen breeding program that are resistant to increasing levels of soda salinity. The experiment was conducted using the filter paper roll germination method. The plant material included seven cultivars and thirteen advanced breeding lines from the collection of the Northern Trans-Urals Research Institute of Agriculture. Seed germination was evaluated in Na2CO3 solutions at concentrations of 9.4, 14.2, and 18.9 mmol/L, corresponding to the total salt content of 1.0, 1.5, and 2.0 g/L, respectively; distilled water served as the control. Resistance was assessed based on a combination of laboratory indices (germination energy and final germination rate) and morphophysiological traits (root length index and phytoeffect). The experiment was conducted in four replications of 50 seeds each using seeds harvested in 2023 and 2024. The varieties Sirius and Tobolyak exhibited high tolerance to Na2CO3 salinity. At the highest salt concentration, their germination rate was 75 and 81%, respectively, while under control conditions it was 95 and 89%, respectively. Under salinity stress, the root length index in Sirius reached 66% of the control, whereas that of Tobolyak was 38%. The varieties Talisman, Otrada, Foma, and Raduzhny demonstrated stable germination at Na2CO3 concentration up to 1.5 g/L, while var. Megion proved to be the most sensitive genotype, which germination rate at this concentration reached only 5%. Among the breeding lines, TM11-6-1 and TM11-4-1 demonstrated the highest salt tolerance. At 2.0 g/L Na2CO3, these lines showed the smallest reduction of the root biomass (18–20% of the control) and maintained germination rates above 70%. The most promising salt-tolerant lines identified were TM11-6-1, TM11-4-1, TM16-43-15, TM16-6-16, and TM16-37-3, which exhibited phytoeffect values of up to 40%.