Chemical constituents from Chenopodium ambrosioides Effects of volatile allelochemicals from Chenopodium ambrosioides on the stoma guard cells in leaf epidermis of Vicia faba STUDIES ON THE CHEMICAL CONSTITUENTS OF THE VOLATILE OIL FROM CHENOPODIUM AMBROSIOIDES L.GROWN IN HUBEI Allelopathicpotential of volatile oil from Chenopodium ambrosioides L. on root tip cells of Vicia faba