Allelopathic Effects Of Extracts And Isolates Of The Aerial Part Of Descurainia Sophia On Wheat

Wheat is one of the most important food crops in China and plays an important role in agricultural production. There is great significance in agricultural production to increase yield of wheat. Weed is one of the most important reasons for wheat yield. Descurainia Sophia,an important companion weed in wheat field can reduce the yield of wheat. The competition of Descurainia Sophia with wheat was considered to reduce wheat yield, but allelopathic effect of Descurainia Sophia on wheat was not often noticed. The allelopathy of Descurainia Sophia on wheat was already studied, but allelochemicals from Descurainia Sophia was not.In order to further study allelopathy of Descurainia sophia on the wheat, allelochemicals of the aerial part of Descurainia Sophia was extracted and separated. Allelopathy of the two components on the ten different varieties of wheat was studied. This reach make contribution to design patterns of cultivation of wheat and, control weed, manufacture new herbicides, increase yield of wheat and develop sustainable agriculture.The main results were summarized as follows:1. Allelopathy of petroleum ether, acetone, ethanol and methanol extract of Descurainia Sophia on the germination and seedling growth of wheat was discussed. The results showed that ethanol extract of Descurainia Sophia inhibit the germination and seedling growth of wheat the most strongly. Ethanol was choosed to extract allelochemicals of Descurainia Sophia.2. The ethanol extract of the aerial part of Descurainia Sophia were separated by four solvents petroleum ether, chloroform, ethyl acetate and butyl alcohol. The results of laboratory bioassays of wheat showed that allelochemicals of Descurainia Sophia mainly exist in the phases of chloroform and ethyl acetate. Components of chloroform and ethyl acetate phases of Descurainia Sophia were separated three times respectively with silica gel column chromatogram. The laboratory guided-bioassays of wheat indicated that component of named NO.19-7-5 separated from phase of chloroform and component of named NO.N-5-5 separated from phase of ethyl acetate showed strongest allelopathy on wheat.3. The allelopathic effects of component of NO. 19-7-5 and N-5-5 on 10 different varieties of wheat were investigated. The results indicated that the two components of Descurainia Sophia had allelopathic effects on all of the 10 different varieties of wheat and allelopathic effects on 10 different varieties of wheat were different. Allelopathic effects of component of NO.9-7-5 on named xiaoyan NO.6 of wheat variety were strongest, and allelopathic effects of component of 19-7-5 on named nongda 211 of wheat variety were weakest. Component of N-5-5 showed strongest allelopathic effects on named xiaoyan NO.6 of wheat variety and showed weakest allelopathic effects on wheat variety named huanong NO.6...