大花金鸡菊叶提取物除草活性的研究

Studies on the Herbicidal Activity of Leave Extracts of Coreopsis grandiflora Hogg.

明确大花金鸡菊叶器官提取物的除草活性,为进一步开展活性化合物的分离研究提供依据。采用甲醇、乙醇和蒸馏水混合提取大花金鸡菊叶中的除草活性物质,进而用石油醚、乙酸乙酯和正丁醇分别对乙醇溶液的提取物进行了液液萃取,最后用琼脂混粉法测定其活性。将提取物在0.625g/L处理浓度下对夏至草和稗幼苗生长均有不同程度的抑制作用,且以乙醇溶液提取物的抑制活性最高,其最佳提取浓度为100%。该浓度乙醇溶液所获得的大花金鸡菊叶提取物在不同处理浓度下对夏至草和稗幼苗的生长均显示了一定的抑制活性,夏至草胚根的有效中浓度(EC50)为0.159g/L,胚轴的EC50为0.595g/L,稗种子根的EC50为0.489g/L,胚芽鞘的EC50为3.43g/L。获得含水相在内的4个萃取相,它们在2g/L的处理浓度下对生菜、小麦、夏至草和稗幼苗生长的抑制作用均以石油醚萃取相最高;大花金鸡菊叶乙醇溶剂提取物及其石油醚萃取相的除草活性均最高,可作为活性物提取的依据。

The research aimed to study the herbicidal activities of leaves extracts in Coreopsis grandillora Hogg, and provide the evidence for further separation study of active compound. The method of grinded plant tissue powders mixed with agar （PPA） was used. The methanol, ethanol and distilled water extracts from the leaves of Coreopsis granditlora Hogg. all showed the different inhibitory effects on the seedlings growth of Lagopsis supine （Steph.） IK.-Gal. and Eehinoehloa cmsgalli （L.） Beauv. with 0.625 g/L concentration, and the ethanol extract showed the highest activity and its optimum extractive concentration was 100%. The leaves extracts obtained with 100% ethanol solution all displayed certain inhibitory activities on seedlings growth of and L. supine at different concentrations and the ECso on radicle of L. supine was 0.159 g/L, hypocotyl of L. supine was 0.595 g/L, and seminal root of E. crusgalli was 0.489 g/L, coleoptile of E. was 3.43 g/L, respectively. Then, the extracts were further sequentially partitioned with petroleum ether, ethyl acetate and buthanol, respectively. Among obtained four fractions including water fraction, the petroleum ether fraction showed the highest inhibitory activities on the seedlings growth of lettuce, wheat, L. supine and E. at 2 g/L concentration. The results showed that the optimum extractive agents of herbicidal active compounds from C. granditlora leaves＇ were ethanol and petroleum ether, respectively.