Impacts of nano-TiO2 on the initial development stages of barley seedlings under salinity

Abstract

The most important development period in cereal plants is the initial stage, that is, seed germination and early seedling development. Even if the barley is thought to be a partially salt-tolerant plant, it may be severely affected when exposed to salinity at initial developmental periods. Pre-treatment and preparation of seeds before sowing have an important in agriculture. Nano-seed priming treatment is a new approach used to increase germination, emergence and seedling growth recently. In this study, the effects of nano-TiO2 (0, 100, 200 mg L-1 n-TiO2) pre-application and ongoing/combination application under salinity (0, 100, 200, 300 mM NaCl) on germination and early seedling growth of barley plants were investigated. Root lengths (RL, mm), germination rates (GR, %), radicle emerging (RE, %), number of coleoptiles (CN) were measured depending on the day (1, 2, 3 days). At the end of the third day, seedling fresh and dry weights (FW,DW mg) were measured. The relative growth index (RGI) of root and mean germination time (MGT) were calculated. It was determined that the application of 100 mg L-1 n-TiO2 increased root length and RGI compared to control groups. It was observed that the application of 100 mg L-1 n-TiO2 significantly increased the germination percentage, biomass and root length especially in 100 mM salt conditions. Also, 100 mg L-1 n-TiO2 increased the RE too in 100 mM salt conditions (1st day). In this study, it was determined that 300 mM NaCl was inhibitory dose, and also germination remained below 20% in 200 mM NaCl in all groups