Effect of water and Poly Amines treatment on barley (Hordeum vulgare L.) c.v Usef seedling vigour and chilling tolerance at harvesting in different seed moisture content

This study was conducted to investigate the  role  of water and polyamines (PAs) as priming  agents on  improving seed vigour and chilling tolerance with  different  moisture  content (Mc)(14.0,16.0,18.0%) under chilling conditions in barley (Hordeum vulgare L.) c.v Usef. Experiments were conducted at the seed and Plant certification and Registration Research Institute in 2013 -2014. The seeds were hand harvested at three initial moisture contents including 18, 16, and 14%  wet weight basis .The seed samples then were sealed in polythene bags and stored in conditioned storage and equilibrium for 8 months. After that for seed priming, seeds were soaked in 20mg/L-1 (w/v) aerated solution of spermine (Spm), Puterscine (Put), and Spermidine (Spd) and distilled water (W) for 16h at 20±2C°. After each treatment, Seeds dried to original moisture level in forced air and sealed in polythene bags, stored in a conditioned storage again until one month. Experimental units were arranged as factorial in a completely randomized design with four replications after treat. The results indicated that Mc18% improved the germination percentage (GP) and seedling vigour compared to Mc 16 and 14%. The electrolyte leakage decreased in seeds harvested by Mc 18% when compared with Mc16 and Mc 14.0%. Also seed treatments significantly increased the seed viability. Likewise, in chilling stress condition maximum proline content and areal dry weight were obtained from Put treat, whereas the lowest electrolyte leakage was recorded for Put treat. Meanwhile, interaction between seed moisture content ×PAs treatment in cold condition significantly affected on plumule length and radicle dry weight, statistically maximum plumule length and radicle dry weight were recorded from Put ×18.0% mc. Also seed priming with water had positive effect on seedling growth after chilling stress.  Generally, the effectiveness of PAs on improving chilling tolerance and increasing seedling vigor was more pronounced in Put treatment along with sample with 18.0% mc.