Effects of osmotic tension and salt stress on germination of three grass species

Effects of osmotic tension, salinity and alkalinity were studied on seed germination of three grasses of Karnal-Kurukshetra region with a view to evaluating their capacity to establish through seeds in saline and alkaline environments. Experiments were conducted under controlled conditions in petri dishes lined with blotting papers that were wetted with non-ionic osmotic solutions of mannitol (–2.5 to –15 bars); salinized solutions of NaCl, Na₂SO₄, MgCl₂ and CaSO₄ (Electrical conductivity, EC, ranging from 4 to 16 dS/m), alkaline solutions of Na₂CO₃ (pH 9 to 10) and also in dishes filled with alkali soil grades of the same pH range. Seed germination of all the three grasses was observed to be delayed and finally suppressed by the stress conditions, magnitude of reduction being related to the kind and level of stress as well as to the species. WhileSorghum halepense showed a strikingly superior stress-resistance,Panicum miliare did not appear to be suited to establishment through seeds.Diplachne fusca, on the other hand, was found to be remarkably adapted to alkalinity.