Physiological responses of six Ophiopogon japonicus germplasms to drought stress

A pot experiment was carried out to determine the effect of drought stress on physiological indexes of six different Ophiopogon japonicas gerplasms (Baoji No.1, Baoji No.2, Beijing, Tianshui, Quxian No.1, Quxian No.2) by measuring relative water content of leaves, MDA (Malondialdehyde) content, free proline accumulation, and to comprehensively evaluate the drought resistance of six gerplasms. The results showed that Baoji No.1 and Beijing growth were inhibited with the period extension of drought stress, and the MDA content and the soluble protein content increased slightly. The leaf relative water content of Baoji No.2 sharply decreased from 73.3% to 58.1%. And the free proine accumulation increased, while SOD activity increased at first then decreased as the period of drought stress increased of six O. japonicas gerplasms. Drought resistance of six O. japonicus germplasms were in following order as Baoji No.1> Beijing > Tianshui > Quxian No.1 > Quxian No.2 > Baoji No.2.