Physiological and biochemical characteristics of drought resistance for oil flax at seedling stage under water stress

This article reports the influence of water on oil flax leaf relative water content( RWC),activity of catalase( CAT) and peroxidase( POD),content of lipid peroxidation products malondialdehyde( MDA) and free proline( Pro) at the seedling stage,using pot experiments with three water treatments. The results showed that the RWC of different drought resistance varieties have different degrees of reduction. Under the moderate and severe water stress,the average RWC decreased by 4. 36% and 13. 74% compared with CK,the average RWC of drought-resistant and drought-sensitive varieties respectively decreased by 7. 67% and 10. 42% compared with CK,the deought-resistant varieties decreased less; and the average CAT and POD activity of drought-resistant varieties increased by 12. 46%,15. 14% and 65. 01%,156. 01%,respectively. The CAT and POD activity enhanced with the increasing of the stress,but the drought-sensitive varieties increased by 46. 84%,29. 85% and 58. 73%,38.20% compared with CK; it appears increasing at first and then decreasing. The content of MDA increased with the increasing of the stress,while that of drought-resistant had a smaller increase( 2. 99%) than that of drought-sensitive. The content of Pro increased with the increasing of the water stress,and the drought-resistant varieties had a higher accumulation of the proline; average increase 108. 64% compared with CK. Overall,RWC and Pro content can be regarded as physiological and biochemical indexes of drought resistance for oil flax at seedling stage.