Abstract

The combined effects of fertilization and drought stress on the growth of Prunella vulgarisand the production of rosmarinic acid (RA), ursolic acid (UA) and oleanolic acid (OA) were investigated. The factors studied included two water conditions and three fertilizer regimes. The results showed that moderate drought stress dramatically decreases spica biomass production but increases the content of RA, UA and OA in spicas of P. vulgaris. Total RA, UA and OA yields were found to be significantly higher in well-watered plants than in drought-stressed plants. An appropriate amount of fertilizer could alleviate the negative effect of drought stress on the growth of P. vulgaris and its production of RA, UA, and OA.The interaction of water and fertilizer treatments significantly influences vegetative dry weight, reproductive dry weight and total RA, UA and OA yields in P. vulgaris. The results suggest that the application of the proper amount of fertilizer aids P. vulgaris production in arid and semi-arid regions and that the combined use of fertilizer and properly timed exposure to drought stress can enhance total RA, UA and OA yields in P. vulgaris.

Key words: Prunella vulgaris L., N, P and K fertilizer, growth, drought, secondary metabolites.