Of Stellera Chamaejasme Leaves Allelopathy And Its Botanical Pesticides Function

In this thesis, the studies on the allelopathy effects and botanic pesticide function of Stellera chamaejasme L., a harmful plant growing on the grassland in the North China, were carried out. S. chamaejasme is poisonous, inedible by livestock, and spreads widely on the grassland, so it does great harm to the development of local stock raising. On one hand, the allelopathy caused by petroleum ether and ethanol extracts of S. chamaejasme leaves on the other plants germination was investigated, on the other hand, the inhibition of the 2 extracts on insects and pathogenic microorganism of crop were tested. The aim of these studies is to provide empirical foundation for the development of a new botanic pesticide.One of the experimental results indicated that different concentrations of two extracts inhibited the radicle and embryo growth of Chloris virgata. Different concentration of petroleum ether extract accelerated the germination of C. virgata L. at different extension. There existed self-poison phenomenon and the RI was up to -1 during the germination of S. chamaejasme when the concentration of petroleum ether extract was 20 gDW.ml-1. Furthermore, different concentrations of ethanol extract inhibited the germination of Lespedeza davurica. and Suaeda heteroptera.The radicle growth of all crop seeds was inhibited by two extracts, and when the concentration of ethanol extract exceeded 5gDW.ml-1, crop seeds germination was claged, too. The radicle of Melicago sativa and Brassica pekinensis turned black and rotted under the effect of 20gDW.ml-1 ethanol extract. The radicle growth of Oryza Sativa was inhibited totally when the concentration of ethanol extract was or higher than 10gDW.ml-1.The corrective mortalities of Acheta domestica and Tenebrio molitor were higher than 50% when the two extracts concentration exceeded 40gDW.ml-1, thereinto corrective mortality of T. molitor was 96.67% under the effect of 40 and 80gDW.ml-1. When the concentrations of two extractswere low, T. molitor L. fetched the food obviously. When the concentrationwas high, the phenomenon wasn't evident but the mortality added. The dead worms were black and would be eaten by congener occasionally.Different concentrations of two extracts did not clag the growth of six epiphytes and three bacteria tested. The further study on other plant pathogenic microorganism needs to be done.The essential oil of S. chamaejasme was part of petroleum ether ex tract of its leaves. Eighteen compounds in the oil were identified by G C/MS. They are: seven ketone compounds: 2-Undecanone,6,10-dimethy, 1-Cyclohexanol-l-butanone, 2,5-Hexanedione, 2(4H)-Benzofuranone,5,6,7, 7,a-tetrahydro-4,4,7a-trimethyl, 3-Buten-2-one,4-(2,6,6-trimethyl-1-cyclohex en-1-yl)-,(E), 6-Dodecanone, 3-Buten-2-one,4-(2,6,6-trimethyl-7-oxabicycl o4.1.0hept-l-yl); three alcoholic compounds: a-terpineol. Benzyl Alcoho 1, Phytol; two alkyl and acyl amine components: Undecane, Tetradecane and Hydrazinecarboxamide,N,N-diphenyl-, Acetamidobenzene; one ester, a Idehyde, alkyne and acid: Butanoic acid: 2-propenyl ester, 1-Octadecyne, 1-Octadecyne, Palmitic acid.Acyl amine compounds containing nitrogen are rare in the plant essential oil. N,N-diphenyl-hydrazinecarboxamide, which content was high to 17.26%, was found in the essential oil extracted from S. chamaejasme leaves. This acyl amine compound maybe the origin of unique pungent scent of S. chamaejasme. Whether it is the important allelochemicals or bioactive chemicals needs to be researched further.The further separation and identification of other allelochemicals in two extracts of S. chamaejasme leaves and the study on the effect mechanism of those allelochemicals will go on if it is possible.