[Effect of water stress on content of active constituents in Erigeron breviscaps].

OBJECTIVE To study the effect of water stress on the content of scutellarin and caffeate in Erigeron breviscaps. METHOD Fv/Fm, N content, as well as the content of scutellarin and caffeate under three water grads were measured. RESULT AND CONCLUSION Fv/Fm of the plant decreased significantly in 8% and 23% water treatment, that proved drought and waterlogging occurred. Under the two conditions, the contents of N were lower but the contents of active constituents were higher than those under 15% treatment. The results support the carbon-nutrient balance hypothesis and the "stress effect hypothesis" for the formation of geo-herbs.