龙柏枝叶水浸提液及其萃取物除草活性的生物测定

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

采用培养皿滤纸法,以油菜（Brassica campestris L.）、反枝苋（Amaranthus retroflexus L.）、生菜（Lactuca sativa L.var.ramosa Hort.）、番茄（Lycopersicon esculentum Miller）和小麦（Triticum aestivum L.）为供试植物,对龙柏（Sabinachinensis‘Kaizuca’）枝叶水浸提液的除草活性进行了生物测定,并以番茄为测定对象,对水浸提液的不同溶剂萃取物的除草活性也进行了生物测定;另外,采用薄层层析法对乙酸乙酯萃取物的除草活性成分进行了初步定性分析。结果显示,在0.05-0.2 g·mL^-1质量浓度范围内,龙柏枝叶水浸提液对5种植物的种子萌发及幼苗根长和茎高均有一定的抑制作用,且随质量浓度的提高,抑制作用逐渐增强,其中0.2 g·mL^-1水浸提液对5种植物的种子萌发及幼苗根长和茎高的抑制率均在80.00%以上,对番茄种子萌发及幼苗根长和茎高的抑制率最高,均达到100.00%。在龙柏枝叶水浸提液的石油醚、乙酸乙酯和水萃取物中,0.01、0.02和0.04 g·mL^-1石油醚或乙酸乙酯萃取物以及0.02和0.04 g·mL^-1水萃取物对番茄种子萌发及幼苗根长和茎高均有一定的抑制作用,且随质量浓度的降低,抑制率逐渐降低;其中,乙酸乙酯萃取物的抑制作用最强,水萃取物的抑制作用最低。薄层层析显色结果表明,龙柏枝叶水浸提液乙酸乙酯萃取物的主要除草活性成分为酚类成分。

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.