[Effects of chitosan treatment on physiological and biochemical characteristics in cucumber seedlings under low...

Chitosan 50 mg/L treatment alleviated the low temperature injury of cucumber seedling membrane. The chitosan treatment reduced electrolyte leakage and the MDA content of cucumber leaves and alleviated the decreases in photosynthetic rate, the photochemical efficiency of photosystem II (PhiPSII), the photochemical quenching of fluorescence (q(P)) and the efficiency of excitation energy captured by the open photosystem II reaction centers (F(v)'/F(m)') under low temperature (6 degrees C). At the same time, the chitosan treatment enhanced the antioxidant enzymatic activities and increased the proline and soluble protein contents in cucumber leaves under low temperature. The results indicated that chitosan treatment improved cold resistance of cucumber seedlings,which protected the membrane system, improved the capability of eliminating active oxygen species and alleviated the damage to photosynthetic organization under low temperature.