Depletion Soil Seed Bank Of Orobanche Minor By Traditional Chinese Medicinal Herbs

The pre-condition periods as well as standard germination stimulatent of GR24 were studied under the different concentration for the O.minor seed germination rate, the result indicated that O. minor germination rate was the highest after 12 days pre-conditioning. Pre-conditioned seeds showed the highest germination percentage after treated by germination stimulant GR24 for 6 days, there after the germination rate keep stable. At the 25℃pre-conditioning temperature, the related equation between the precondition periods and the O. minor seeds germination percentage is y=-0.5227x2+12.032x-0.751(R=0.9051). The optimum concentration of GR24 for O. minor seeds germination is 0.1μmol·L-1. The result indicated there were no significant differences for O .minor to achieve the greastest germination rate when addition GA3 during precondition periods comparing to the result with Salam. It is suggested that GA3 have no effects for reducing the priconditon periods, but it can reduce the time s of O. minor seeds to achieve the highest germination rate when treated by GR24.Traditional Chinese medicinal herbs (240 species) were screened for testing their ability to induce or inhibit the germination of O. minor seeds by four extracts of different concentration(undiluted, 10-fold dilution, 100-fold dilution, and 1000-fold dilution). The results indicate that the following herbs water extracts, which induced O. minor seeds germination rate greater than 70%, were Juncus effuses L. var. decipiens Buchen., Quisqualis indica L., and Nelumbo nucifera Gaertn. Herbs methanolic extracts, which induced O. minor germination rate greater than 70%, were Stemona japonica (BL.) Miq., Morus alba L., Oryza sativa L., and Dioscorea hypoglauca Palib. In addition, herbs water extracts, which the inhibition rate greater than 50%, were Chrysanthemum morifolium Ramat., Trachycarpus wagnerianus Becc., Prunus armeniaca L., and Phellodendron amurense Rupr. Herb methanolic extracts, which the inhibition rate greater than 70%, were Dipsacus asper Wall, Rehmannia glutinosa (Gaertn.), Myristica fragrans Houtt., Kochia scoparia (L.) Schrad., Coptis chinensis Franch., Equisetum hiemale L.,and Picrorrhiza hurrooa Royle ex Benth. The result of this study displayed that some herbs could induce and/or inhibit germination of O. minor seeds, which were changed with differ0zxent concentrations. The contents of active substances from different herbs are different.Thin Layer Chromatography (TLC) was applied for the separation of Quisqualis indica L. active substances which can induce the seeds germination of O. minor. The results indicated that all active substances can be partitioned into ethyl acetate phase after 6 times partitioning. The ethyl acetate was removed by rotory evaporator. The residues were diluted into 10-, 100 -, 1000-, 10,000-, 20,000 -, 100,000 -, 200,000 - and 1,000,000-fold, repectively. The germination rate had significant difference between 10-fold dilutions and the other concentrations, but there were no significant difference among the other concentrations except 10-fold treatment, and the lowest germination rate was 38.5%. It was displayed that the active substance which can induce seeds germination of O. minor, are contained in the 4th band and the 7th bands. It was preliminary concluded that there were may be two kinds active material which can induce germination of O. minor in Q. indica water extracts.