Bioassay of herbicidal activity of water extract from branch and leaf of Sabina chinensis 'Kaizuca' and its partitioned extracts

Using Brassica campestris L.,Amaranthus retroflexus L.,Lactuca sativa L.var.ramosa Hort.,Lycopersicon esculentum Miller and Triticum aestivum L.as tested plants,bioassay of herbicidal activity of water extract from branch and leaf of Sabina chinensis 'Kaizuca' was studied by the culture dish-filter paper method,and that of its partitioned extracts by different solvents was also carried on using L.esculentum as tested plant.Furthermore,the active component of ethyl acetate partitioned extract was preliminarily qualitatively analyzed by means of the thin layer chromatography(TLC) method.The results show that in concentration range of 0.05-0.2 g·mL-1,the water extract has a certain inhibition to seed germination,seedling root length and seedling stem height of five tested plants,and the inhibition gradually enhances with increasing of concentration.The inhibition rates of 0.2 g·mL-1 water extract to seed germination,seedling root length and seedling stem height of five tested plants are all above 80.00%,in which the inhibition rates to those of L.esculentum are the highest with the rates of 100.00%.In petroleum ether,ethyl acetate and water partitioned extracts from water extract of branch and leaf of S.chinensis 'Kaizuca',0.01,0.02 and 0.04 g·mL-1 petroleum ether or ethyl acetate partitioned extracts,and 0.02 and 0.04 g·mL-1 water partitioned extracts all have a certain inhibition to seed germination,seedling root length and seedling stem height of L.esculentum,and the inhibition rates reduce gradually with decreasing of concentration.In which,the inhibition effect of ethyl acetate partitioned extract is the strongest,that of water partitioned extract is the lowest.The color result of TLC shows that in ethyl acetate partitioned extract from water extract of branch and leaf of S.chinensis 'Kaizuca',the main herbicidal active components are phenolic compounds.