Effect of Continuous Cropping on the Essential Oils of Angelica sinensis (Oliv.) Diels

This research is to compare with the yield and constituent of the essential oils extracted from the Angelica sinensis(Oliv.)Diels in different rotation system.Water steam and GC-MS were used.The yields of the essential oil of Angelica sinensis are 0.95%,0.75%,0.70%,0.64%,respectively in potato-wheat-Angelica sinensis,Angelica sinensis-wheat-Angelica sinensis,wheat-Angelica sinensis-Angelica sinensis,Angelica sinensis-Angelica sinensis-Angelica sinensis.The relative amounts of Ligustilide of essential oil are 71.62%,49.04%,29.49%,59.58%,respectively.The relative amounts of phthalic anhydride and 1,4-cyclohexadiene-1,2-dicarboxylic anhydride(which is isomerization products form Ligustilide) of essential oil are 0.21% and 4.47%,3.81% and 8.55%,6.48% and 10.65%,1.04% and 5.33%.The yields of the essential oil and the relative amounts of ligustilide are different considerably,while the constituents of the essential oil of Angelica sinensis from different rotation systems are identical.