Study on effect of hydropriming duration and temperature on some seed and seedling physiological characteristics of rainfed wheat (Triticum aestivum L.) Kouhdasht cultivar under drought stress

Low soil moisture content is one of the major problems in arid and semi-arid regions that leads to weak and nonsynchronous seedling emergence and establishment, finally resulting in the yield lose. Seed hydropriming mitigates somewhat these adverse drought effects. Therefore, in current study the effective factors in seed hydropriming such as time and temperature are evaluated on physiological quality of seed and seedling of a rainfed wheat (Var Kouhdasht) under drought stress. Pot experiment was carried out as factorial with three replications in base of the RCBD under drought stress conditions in Lorestan University. Drought levels were 25, 50 and 75% field capacity. Hydropriming time and temperature levels were 12, 18, 24 h and 15, 20, 25 ° C, respectively. Percent and speed of seedling emergence, seedling growth rate, leaf area index, chlorophyll index and number of root branches were studied. Results showed that the most of traits decreased by drought progress. Also, hydropriming temperature affected emergence percent and speed, seedling growth rate and chlorophyll index. Maximum of these traits was obtained when the seed primed at 25 ◦C. Interaction of drought and hydropriming time was significant for seedling emergence percentage and there was an interaction between priming temperature and priming time for LAI. Seed priming for 12 h was the best time for increasing seedling emergence at mild drought stress. But there was no difference between priming times at sever stress. According to importance of seedling emergence and speed, seed hydropriming of this cultivar for 12 hour at 20 or 25 ◦C is suggestibel.