OBJECTIVETo study the effect of waterlogging stress on medicinal Chrysanthemum morifolium during the seedling stage and build a reliable evaluation of flooding tolerance indicator system.

METHODThe three cultivars: C. morifolium cv. Hongxinju, C. morifolium cv. Xiaobaiju and C. morifolium cv. Changbanju were studied for the and the effect of waterlogging stress on their physiological and biochemical chracteristics.

RESULTWith the extension of waterlogging, the content of chlorophyll and relative leaf water potential were decreased, meanwhile malonaldehyde (MDA), glutathione (GSH) and soluble sugar were increased. The catalase (CAT) of C. morifolium cv. Hongxinju rose at first and then dropped and CAT of C. morifolium cv. Xiaobailu and C. morifolium cv. Changbanju declined at first before decreased, and then dropped again. The peroxidase (POD) rose firstly before decrease and then increases again. After the waterlogging treatments which last for 4 days, the physiology and biochemistry characteristics can not restore to the comparison (CK) within 3 days.

CONCLUSIONFour days waterlogging treatment had made serious damage on medicinal Chrysanthemum. Among three cultivars, C. morifolium Ramat. cv. Hongxinju showed the highest tolerance ability, while C. morifolium cv. Changbanju was the lowest, and C. morifolium cv. Xiaobaiu was in the middle. The malonaldehyde (MDA) and catalase (CAT) could be the main physiological and biochemical indexes to reflect the tolerance ability against waterlogging.