Effects of seed pretreatment with potassium nitrate on germination and heterotrophic growth of wheat seedlings at different levels of drought stress

The present study was conducted in order to evaluate the effect of seed priming on germination and heterotrophic growth of wheat seedling in drought stress conditions at at factorial experiment based on complete randomized design at Faculty of Agriculture, University of Maragheh. Experimental treatments were of five levels of drought (0, -3, -6, -9 and -12 Bar) and three levels of potassium nitrate (KNO3) (0, 2 and 4 percent). The results showed that rate the percentage of germination reduced with increasingstress levels. Effect of seed priming on germination rate and the mean germination time was positive in control level(0 bar), but the positive effect unobserved with increasing severity of drought. So that the lowest germination rate and maximum mean germination time was in -12 bar. Investigation of components heterotrophic growth revealed that the prime with of 2 % concentration potassium nitrate have the most significant effect on drought tolerance at traits seed reserve utilization rate, seed reserve utilization efficiency and seed reserve depletion percentage. Also the vigor index and seedling dry weight in treatments primed at levels of 2% potassium nitrate in drought levels was observed most significant change. Therefore can stated that seed priming with potassium nitrate via positive effect on heterotrophic growth of wheat seedling under drought stress may desirable performance under drought stress in wheat growth.