The Preliminary Investigation Of The Allelopathy On The Dioscorea Opposita Thunb

Based on the continuous cropping obstacles of Dioscorea opposita Thunb, the allelopathy ofDioscorea opposita Thunb was studied from the analytical chemistry perspective. The main contents are asfollows:1. Review on allelopathyEfforts and achievements on allelopathy including, allelochemicals, the mechanism of allelopathy, theallelopathy of medicinal plant, the continuous cropping obstacles, and ultimately the application of all thesein the management of natural and agricultural ecosystems are reviewed.2. An HPLC method was developed for simultaneous determination of batatasin Ⅰ, Ⅲ, Ⅳ and Ⅴ indifferent parts of Dioscorea opposita ThunbFor the first time, high-performance liquid chromatography (HPLC) with UV detection coupled withultrasonic extraction as an efficient sample preparation has been developed for the simultaneousdetermination of four batatasins (Ⅰ, Ⅲ, Ⅳ and Ⅴ) in Dioscorea opposita Thunb. The content of the fourbatatasins in tuber, peel, stem, and bubil were determined by the established method, respectively. Themobile phase was composed of methanol (solvent A) and H2O (solvent B). Separation was carried out on areversed-phase colum (Aglient HC-C18,4.6×250mm,5μm, Aglient, Waldbronn, Germany). The gradientelution program was:50%B (0-20min),50-65%B (20-65min). The flow rate was1mL/min, columtemperature was set at30℃. The UV spectra was set at274nm and all the inject volume was20μL. Itwas found that batatasin Ⅰ and Ⅲ both exist in these parts: bubils, stem, peel and tuber. Besides, the bubilsand stem contain batatasin Ⅳ and Ⅴ. Batatasin Ⅴ was also found in the peel. By comparison, batatasin Ⅰ,Ⅲ and Ⅴ exist mostly in the peel, but batatasin Ⅳ in the bubils.3. BioassayTo study the continuous cropping obstacles and allelopathy, we study the effects of the aqueous extractfrom soil, tuber, bulbils and stem with different concentrations on the germination, radicle length, andseeding growth of bulbils and wheat seeds. The bulbils and wheat were treated through the indoor bioassaymethod and petri dish filter paper cultivation method. Compared with the control group, the results showedthat the soil extracts had no obvious inhibitory effect on the germination of bulbils, but promoted the growth of radical. Soil aqueous extracts in low concentrations could promote wheat seed germination, butinhibit in high concentrations. All the other three aqueous extracts had inhibition action on the seedgermination and radicle length of bulbils and wheat, and seeding growth of wheat. In addition, theinhibition increased with the concentration rising.