Abstract: The seedlings and germinating seeds of rapeseed (B. napus L.) with different waterlogging tolerance (WT) were used to analysis the physiological reaction in anoxic stress. After 12h anoxic stress to germinated seeds, the waterlogging tolerant genotype was different significantly than susceptive genotype with higher relative root and shoot length, fresh weight, survivor rate and relative vigor index, but lower electrical conductance. Without anoxic stress, the three seedling leaves of WT genotype had lower soluble sugar and similar lever in soluble, proline and malnodialdehyde (MDA) content than susceptive genotype. After 48h anoxic stress to three leaves seedling, the WT genotype showed significant different physiological reactions compared to the susceptive genotype with the rapid increase of soluble sugar and proline contents, lower relative electrical conductivity and MDA content. The different physiological reaction also occured in activities changes of activated oxygen scavenger enzyme, activities of the peroxidase (POD) and superoxide dismutase (SOD) of WT genotype increased rapidly but catalase (CAT) decreased after anoxic stress, where susceptive genotype with similar SOD, increase in CAT but decrease in POD.

Key words: Rapeseed, anoxic, Waterlogging tolerance,