Water stress on seed germination
Water stress
When water demand exceeds the available amount, the various changes are observed with various sclales from molecule to ecosystem.
Water stress on seed germination
When water is deficient, seed germination percentage often decreases to avoid drought stress on seedlings.
Protocol to detect the effects of water stress on seed germination
Method 1 (classical method)
Changes in the thickness of seed bed by adjustijng nunmber of filter peaprs, and keeping constant water table by adjusting water supply
Method 2
Preparation
Making osmotic pressure gradient by the concentration of polyethylene glycol (PEG)
Equation on making osmotic perssure using PEG-6000
ψs = -(1.18 × 10-2)C - (1.18 × 10-4)C2 + (2.67 × 10-4)CT + (8.39 × 10-7)C2T
ψs: osmotic pressure (bar)
C: concentration (g/kg)
T: temperature (°C)
(Michel & Kaufmann 1973)
References
- Michel BE & Kaufmann MR. 1973. The osmotic potential of polyethylene glycol 6000. Plant Physiology 51: 914-916
Polyethylene glycol (PEG)
≈ polyethylene oxide (PEO), and polyoxyethylene (POE)
PEG: tended to refer to oligomers and polymers with a molecular mass < 20000 g/mol
PEO: tended to polymers with a molecular mass > 20000 g/mol
POE: tended to a polymer of any molecular mass.