OBJECTIVETo determine 5 phenolic acids in the soils around rhizosphere of Rehmannia glutinosa in the field under normal rotation and successive cropping.

METHODPhenolic acids related to allelopathy effect in the soils around rhizosphere of R. glutinosa were determined by HPLC.

RESULTThe growth of R. glutinosa under normal rotation was strong. During harvest, the dry weight of the root tube and the volume of the R. glutinosa under normal rotation were 6.02 and 7.71 times of the ones under successive cropping.

CONCLUSIONThe seeding stage and elongating stage are the crucial periods for the autotoxic effect of the R. glutinosa under continuous cropping. During these periods, the content of coumaric acid, 4-hydroxybenzoic acid, syringic acid, and ferulic acid of R. glutinosa under successive cropping are notably negative correlation with the growth of the leaf and root tuber of R. glutinosa under successive cropping. Among them, ferulic acid plays a major role in the restriction effect on R. glutinosa under successive cropping.

Chromatography, High Pressure Liquid ; Coumaric Acids ; analysis ; metabolism ; toxicity ; Gallic Acid ; analogs & derivatives ; analysis ; metabolism ; toxicity ; Hydroxybenzoates ; analysis ; metabolism ; toxicity ; Plant Leaves ; drug effects ; growth & development ; Plant Roots ; drug effects ; growth & development ; Rehmannia ; drug effects ; growth & development ; metabolism ; Soil ; analysis

OBJECTIVETo study the effects of continuous cropping obstacles on growth of Rehmannia glutinosa.

METHODThe growth indexes, activity of root ATPase, root activity and mineral nutritional absorption were determined.

RESULTContinuous copping decreased growth rate and declined the size of leaves. Activity of root ATPase and root activity were also inhibited.

CONCLUSIONThe deficiency of source capacity is an important factor to restrain the root development of R. glutinosa with continuous cropping, the decrease of root activity and ATPase activity as well as nutritional stress of potassium and nitrogen are the reasons for the effects of continuous cropping on the growth and development of R. glutinosa.

Absorption ; Adenosine Triphosphatases ; metabolism ; Plant Roots ; enzymology ; growth & development ; metabolism ; Rehmannia ; enzymology ; growth & development ; metabolism ; Stress, Physiological

Effects of the leaf-clipped treatment on growth and physiological properties of Rehmannia glutinosa were studied. Result showed that with the increase of the cutting leaves degree, growth rates of shoots and roots were decreased, sugar contents declined, chlorophyll contents decreased and root activities also inhibited. Compared with the normal plant (CK), the root inhibit rates in T1, T2, T3 were 17.53%, 33.41%, 59.47%, respectively. Physiological indexes including chlorophyll contents, root activities and sugar contents also were impacted by the leaf-clipped treatment. The results indicate that to balance source-sink relationship is a very essential method for improving production of R. glutinosa.
Agriculture ; Carbohydrate Metabolism ; Carbohydrates ; analysis ; Chlorophyll ; analysis ; metabolism ; Plant Leaves ; chemistry ; growth & development ; physiology ; Rehmannia ; chemistry ; growth & development ; physiology