SEED PRIMING OF BREAD WHEAT TO IMPROVE GERMINATION UNDER DROUGHT STRESS

Experiments were conducted during 2011 in the laboratories of the Davy's building, School of Biomedical and Biological Sciences, University of Plymouth, UK. The experiment aimed to improve the germination of wheat bread seed (Triticum aestivum L. cv. Caxton) under drought stress via priming, and to determine the levels of drought stress that make seed priming not recommended. Primed and non primed seeds (control) and several levels of negative potentials (0, -0.5, -1, 1.5 and -2 MPa) as drought stress were tested. A completely randomized design with four replicates was used. The results showed that primed seed gave faster ending of germination (LDG), little difference in germination speed between the fast and slow germination members of a seed lot (TSG), faster population of seeds had germinate (MGT), highest first count (FG), highest final count (FIG), highest rapidity of germination which increases when the number of germinated seeds increases and the time required for germination decreases (CVG), highest and faster percentage of germination on each day of the germination period (GRI) compared with control treatment (non primed). Increasing of negative potentials up to -2 MPa led to an increase in LDG, TSG, and MGT, and a decrease in FG, FIG, CVG, and GRI compared with zero potential. Primed seeds had positive effect on (LDG), (TSG), (MGT), (FG), (CVG) and (GRI) compared with non primed seed under the same negative potentials. Whereas improved the (FIG) up to -1 MPa. We conclude, that technique of seeds priming can be use to improve the viability and vigour of seeds under drought stress <= -1 MPa through the escaping mechanism. On other hand, it's not recommend if the drought stress > -1 MPa.