The seed of rice (Oryza sativa L. ) was treated with 1.0-20μg/L DA-6 solution, the effects of DA - 6 on cold resistance of rice seedling were studied. It was found that the survive percentage of seedling under cold stress was increased, electrolyte leakage and malondialdehyde (MDA) contents were decreaed,and the activities of superoxide dismutase (SOD) ,cata;ase (CAT)were enhanced and the decomposition rates of chlorophyll, protein and Soluble sugar were slower, and prolioe content, photosyn-thetic rate , r...