小麦化感作用物的提取,分离及其对白茅的杀除效果

小麦颖壳提取物经3520树脂分离后,对所得甲醇洗脱物离心,分得油类似物、上清液及沉淀物。前两个组分在300mg/L的浓度下,对白茅生长抑制率分别为100％和98％。上清液经硅胶柱分离,得7个亚组分,其中第1、3和7号亚组分在500mg/L浓度下对白茅生长的抑制率分别为95％、91％和95％。第3亚组分经葡聚糖凝胶柱分离,又分得A、B、C 3个组分,褐色粉末状的B组分在1000mg/L浓度下使白茅的生长量下降81％。从而证明小麦颖壳对白茅的化感作用是由多个化感物共同作用的结果。室内和温室及大田的测定结果表明,小麦颖壳中的甲醇洗脱物在24mg/株的剂量下对白茅生长的抑制率可达90％以上。这暗示,小麦颖壳中的甲醇可溶物可望开发成为防治白茅的生物除草剂。

EXTRACTION AND SEPARATION OF ALLELOCHEMICALS IN WHEAT AND ITS HERBICIDAL EFFICACY ON IMPERATA CYLINDRICA

Bioassay results showed that the oil and supernatants separated by Resin 3520 from aqueous extracts of wheat glumness,the subfraction No. 1,3 and 7 separated by Silica Gel column from the supernatants and the fraction B separated by Sephadex column from No. 3 were all very toxic to I. cylindrica.The extraction and fractionation results indicated that allelopathy of wheat to I. cylindrica is a complex effect induced by more than one allelochemical.The test results in laboratory, greenhouse and field showed that methanol elutes from the aqueous extracts of wheat are worthy to be developed as natural-source herbicide for the control of I. cylindrica.