Abstract:

In order to ascertain the allelopathic mechanisms of different varieties of white clover, the major physiological and biochemical parameters of barnyardgrass treated by aqueous extracts of four different varieties (‘Persistent’, ‘Haifa’, ‘Huia’, and ‘Koala’) of white clover at different concentrations were determined during the seed germination and seedling growth stage. The results showed that: the water extract of ‘Huia’ significantly inhibited germination potential and germination rate of barnyardgrass at the concentration of 0.25 g·mL^-1 (P <0.05). The water extracts of all the four varieties of white clover inhibited the seedling height of barnyardgrass at higher concentrations, but the inhibition on its root length were not significant. And the water extract of ‘koala’ significantly inhibited the seedling and root dry weight per plant of barnyardgrass at 0.20 g·mL^-1 concentration (P <0.05). The aqueous extracts of ‘Persistent’ and ‘Haifa’ inhibited the SOD activity of barnyardgrass seedlings (P <0.05), while ‘Huia’ extraction significantly increased the SOD activity of barnyardgrass seedlings (P <0.05). After treated by ‘Persistent’, ‘Haifa’ and ‘Koala’ extractions, the CAT activity of barnyardgrass seedlings firstly increased and then decreased, and POD activity of barnyardgrass seedling significantly decreased (P <0.05) after treated by ‘Haifa’, ‘Huia’ and ‘koala’ extractions. At the same time, aqueous extracts of each variety had changed the MDA content of barnyardgrass seedlings, and there was an increased trend. In summary, four tested varieties of white clover had allelopathy, and there were differences among them.

Key words: White clover, Different varieties, Barnyardgrass, Aqueous extracts, Allelopathy

摘要：

为探明不同品种白三叶（Trifolium repens）水浸提液的化感作用机制，分别测定了‘铺地’（Persistent）、‘海发’（Haifa）、‘威亚’（Huia）、‘考拉’（Koala）4个供试品种对无芒稗（Echinochloa crusgalli）种子萌发及幼苗生理生化指标的影响。结果表明：'威亚'水浸提液在0.25 g·mL^-1浓度处理下，显著抑制了无芒稗种子的发芽势和发芽率（P<0.05）；4个品种白三叶水浸提液均在较高浓度处理下对无芒稗苗高具有抑制作用，但对其根长的抑制作用不显著；而‘考拉’水浸提液在0.20 g·mL^-1浓度处理下，显著抑制了其单株苗干重和根干重（P<0.05）。此外，‘铺地’和‘海发’水浸提液显著抑制了无芒稗幼苗的超氧化物歧化酶（SOD）活性（P<0.05）；‘威亚’水浸提液显著提高了无芒稗幼苗的SOD活性（P<0.05）；‘铺地’、‘海发’和‘考拉’水浸提液处理后其过氧化氢酶（CAT）活性有先上升后下降的趋势；‘海发’、‘威亚’和‘考拉’水浸提液处理下，无芒稗幼苗过氧化物酶（POD）活性有显著降低的趋势（P<0.05）；同时各品种的水浸提液处理均改变了无芒稗幼苗的丙二醛（MDA）含量，使之有增加趋势。综上所述，4个供试白三叶品种均具有化感作用，且品种之间存在差异。

关键词: 白三叶, 不同品种, 无芒稗, 水浸提液, 化感作用