Physiological and Biochemical Reaction Responses to Sclerotium Blight Inoculation among Different Rapeseed Varieties

Different rapeseed(Brassica napus L.) varieties,such as Zhong R-888,Ning RS-1,783,Ningyou 7,Wanyouzao and Aijiazao,with different resistance to sclerotium blight(Sclerotinia sclerotiorum) were selected as materials six days after S.sclerotiorum was inoculated on rapeseed leaf at full bloom stage.The complete functional leaf were chosen to analyze the physiological and biochemical characters such as the content of malondialdehyde(MDA),proline(Pro),free amino acid(FAA),the activity of peroxidase(POD) and polyphenol oxidase(PPO) and conductivity.The results showed that all the physiological and biochemical characters of all selected varieties changed after the inoculation.The increase of Pro content and POD activity in the resistant varieties such as Zhong R-888,Ning RS-1 and 783 was higher than that of the less-resistant varieties such as Ningyou 7,Wanyouzao and Aijiazao.On the contrary,the increase of MDA,FAA,conductivity and PPO in less-resistant varieties was higher than that of resistant varieties.The results also indicated that change of the content or activity of the physiological and biochemical characters after inoculation is correlated with S.sclerotiniose resistance to some degree.