EFFECT OF POLYAMINES APPLICATION ON GERMINATION AND PHYSIOLOGICAL CHARACTERISTICSOF BORAGE (Borago officinalis L.)

The aim of study was determine the advantages of re-drying after seed priming by polyamines. As biologically active compounds, polyamines (PAs) have been considered as modulator of plant growth and development, they play a significant role in plant response to environmental stress. The effects of polyamines priming on seed germination, emergence and seedling growth of borage plants was investigated by a laboratory experiment in factorial layout with complete randomized design (CRD) conducted in three replications. The seeds were classified into five sub-samples one of which was kept as control (unprimed) while the rest of them were primed with polyamines. Seeds pre-treatments included: control (unprimed), water pretreatment for 4 and 8 h, spermidine at 5 and 5.5 mM for 4 and 8 h, spermine at 2.5 and 3 mM for 4 and 8 h, putrescine at 2.5 and 3 mM for 4 and 8 h. Sseed treatments with polyamine led to earlier and enhanced germination. Improved seedling length, seedling fresh and dry weight as well as vigor index were found in polyamine-treated seeds. Moreover, the majority of priming treatments enhanced seedling emergence percentage, emergence energy and coefficient of uniformity of emergence (CUE) as compared with control samples. Non-primed seeds (control samples) significantly showed the least α-amylase and β-amylase activity (0.293 and 4.923 U.mg^ -1 Protein, respectively ) and shortest of plant height. 4-hour seed treatment by 3mM putrescine and 8-hour treatment with 3mM spermine were recognized as the most effective treatments in most of the studied traits.