不同年限紫花苜蓿的浸提液对棉花的化感作用及其化感物质含量

Study on the allelopathy effect and allelochemicals content of extracts from different ages of alfalfa on cotton

通过培养皿滤纸法的生物检测方法研究了3种浓度(0.100、0.050和0.025 g/mL)的苜蓿Medicago sativa茎叶提取液对棉花Gossypiumspp.幼苗生长及发芽的影响,以探明紫花苜蓿对棉花的化感作用。结果表明:提取液对棉花种子发芽率有抑制作用,且随浓度的升高,抑制作用加强;用生长第2、3和4年的苜蓿的提取液处理棉花种子,不同处理下棉花种子发芽率低于对照,与对照差异显著(P<0.05);第3年苜蓿茎叶提取液对棉花种子抑制作用最大;高效液相色谱法(HPLC)分析苜蓿提取液成分,发现生长不同年限苜蓿提取液中酚酸含量由高到低的排列顺序为,生长第3年苜蓿茎叶提取液>生长第4年苜蓿茎叶提取液>生长第2年苜蓿茎叶提取液>生长第2年苜蓿根提取液>生长第4年苜蓿根的提取液>生长第3年苜蓿根提取液。

The allelopathy of alfalfa was studied by the method of bioassay of culture plate and filter paper in order to explore how the treatments with three extract concentrations （0. 100,0. 050,0. 025 g/mL） of alfalfa affected the growth and germination of cotton. The results showed that the extract concentrations of alfalfa apparently inhibited the growth of seedling and root of cotton, and the inhibition was stronger with the increase of extract concentrations. Treating cotton seeds with extracts from leaves and stem of 2-year-old, 3-years-old and 4-years-old alfalfa, the cotton＇s seed germination were lower than the comparison, and the difference was significant （P〈0.05）. The strongest inhibition occurred in extract from 3-year-old alfalfa leaves and stem. Four phenolic acids content of the alfalfa aqueous extracts were analyzed with high performance liquid chromatography （HPLC）. The four phe- nolic acids content was the highest in 3-year-old alfalfa leaves and stem extract, followed by 4-year-old alfalfa leaves and stem extract, 2-year-old alfalfa leaves and stem extract, 2-year-old alfalfa root, 4- year-old alfalfa root, and 3-year-old alfalfa root extract, sequentially.