紫茎泽兰叶片提取物对4种杂草种子萌发及幼苗生长的抑制效应

为研究紫茎泽兰叶片提取物对杂草生长发育的抑制效应及作用机制,用纸卷发芽和盆栽试验等方法,研究了不同浓度梯度(200、400、600、800、1 000 mg·L-1)的紫茎泽兰叶片提取物,对鬼针草、马齿苋、猪毛菜和鹅绒藤4种田间杂草种子萌发和幼苗生长的影响.发芽试验结果表明,杂草种子的萌发指标随提取物浓度增加而降低,当...

The Inhibitory Effect of Leaf Extract of Eupatorium adenophorum Spreng. on Seed Germination and Seedling Growth of Four Species of Weeds

In order to study the inhibitory effect and mechanism of Eupatorium adenophorum leaf extract on weed growth and development, four species of common weeds in fields, Bidens pilosa L., Portulaca oleracea L., Salsola collina Pall., and Cynanchum chinense R.Br., were selected as experimental materials. The paper roller-sprouting method and pot culture method were used to study the effects of different concentrations of leaf extracts (200, 400, 600, 800, 1 000 mg·L^-1) from E. adenophorum on seed germination and seedling growth of four weed species. The germination test showed that the germination index of weed seeds decreased with the increase of the E. adenophorum leaf extract concentration, when the concentration was 600 mg·L^-1, compared with the control, seed germination potential, germination rate, germination index and vigor index in E. adenophorum leaf extracts-treated weeds were significantly decreased. The pot culture test showed that, the inhibition rate of the extracts on root length and fresh weight of the tested weed seedlings both followed the order of C. chinense >S. collina >P. oleracea >B. pilosa. Further study suggested that E. adenophorum leaf extracts-treated induced the antioxidant enzyme activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) increased, and the contents of ascorbic acid (AsA), glutathione (GSH) and osmotic adjustment substances-proline were improved. Meanwhile, the levels of malondialdehyde (MDA) and superoxide anion free radical ($O_2^{-}$) also were increased. Taken together, these findings indicate that the oxidative stress of E. adenophorum extracts on weeds is the internal mechanism that leads to the decrease of seed germination index and inhibition of seedling growth. This finding provides a theoretical basis for the application of E. adenophorum leaf extract in farmland weed control.