SEED PRIMING EFFECTS ON MORPHOLOGICAL TRAITS OF AMARANTHUS HYPOCHONDRIACUS UNDER OPTIMAL AND LOW TEMPERATURES

The recent research evaluated the effects of growth stimulant seed treatment on the morphological traits of Amaranthus hypochondriacus L. cv. 'Krepysh' grown under optimal , low positive temperature conditions. The seeds were continuously soaked for 4 h in five different solutions of growth stimulants, i.e., salicylic acid (SAA -138 mg/L), hydrogen peroxide (H2O2 -10 and 50 mmol/L), calcium chloride (CaCl2 -3000 mg/L), succinic acid (SUA -500 mg/L) , control (distilled water). The stimulant-primed seeds were germinated at optimal temperature (23 degrees C) and continued to germinate at low temperatures of 10 degrees C (T10) and 23 degrees C (T23). The results showed that seed germination rates viz., germination potential (GP), germination rate (GR), germination index (GI), viability index (VI), and seed vigor index (SVI), were significantly improved with seed quality potential compared with the control. Under low positive temperature, seeds treated with succinic acid, H2O2 , CaCl2 had the most significant effects on improving seed quality and induced cold resistance in the seeds. The morphological indicators of amaranth seedlings, i.e., biomass, hypocotyl, and root length, were also significantly improved with seed treatment by growth stimulants. Priming of amaranth seeds with hydrogen peroxide and succinic acid showed a greater increase in seedlings' biomass at room (23 degrees C) and low (10 degrees C) temperatures. The seed treatment with SUA and SAA significantly contributed to enhancing the hypocotyl length. The amaranth roots achieved maximum length after seed treatment with SUA and CaCl2. In general, the seed treatment effects on seedling's biomass under chilling stress were associated with the potential of inducing cold tolerance in seedlings.