effects of seed coating with polyvinyl alcohol and zinc oxidenanoparticles on germination index of wheat

In order to study the effect of seed coating with polyvinyl alcohol (pva) and zinc oxide nanoparticles (zno nps) on germination index of wheat under salinity stress, a factorial laboratory study was conducted in a completely randomized design with 3 replications. the factors are including different levels of salinity stress (0, 2, 4 and 6 ds m-1), different amounts of pva (0, 1.5 and 2.5% by weight-volume) and different percentages of zno nano-particles (0, 2%, 4% and 6% of the amount of pva). in this study, the scanning electron microscopy (sem) was also performed to evaluate the morphology of the applied coating. the results showed that increasing salinity in all treatments significantly reduced the germination percentage. the use of pva on seeds had the positive effects on germination percentage at high salinity levels compared to seed without coating (although it was not statistically significant). in addition, at higher levels of salinity, application of zno at high level (6%) showed more efficient effects on germination index.