外来入侵植物大狼把草提取物的化感潜力

通过室内观察外来入侵植物大狼把草提取物对黄花草木樨、北美车前、胜红蓟和鸡眼草4种植物种子萌发和幼苗生长的影响,研究大狼把草提取物的化感活性。结果表明:大狼把草250～4 000μg·mL-1的乙醇提取物对北美车前、胜红蓟和500～4 000μg·mL-1的水提取物对胜红蓟种子萌发有显著抑制作用,相应的最大抑制率分别为60.80%、48.08%和63.64%。250～1 000μg·mL-1的乙醇提取物和250～2 000μg·mL-1的水提取物对黄花草木樨幼苗根长以及250～500μg·mL-1的乙醇提取物和250～2 000μg·mL-1的水提取物对黄花草木樨幼苗苗高有显著促进作用,相应的最大促进率分别为32.99%、54.45%、11.55%和18.12%,而4 000μg·mL-1的乙醇提取物对其幼苗根长有显著抑制作用,相应的抑制率为22.32%。1 000～4 000μg·mL-1的水提取物和2 000～4 000μg·mL-1的乙醇提取物对北美车前幼苗根长以及4 000μg·mL-1的乙醇提取物对其幼苗苗高有显著抑制作用,相应的最大抑制率分别为19.96%、33.10%和23.15%。250～4 000μg·mL-1的水提取物和1 000～4 000μg·mL-1的乙醇提取物对胜红蓟幼苗根长以及2 000～4 000μg·mL-1的乙醇提取物和水提取物对其幼苗苗高均有显著抑制作用,相应的最大抑制率分别为60.92%、40.80%、11.31%和11.65%。250～2 000μg·mL-1的乙醇提取物对鸡眼草幼苗根长和苗高以及1 000μg·mL-1的乙醇提取物对其幼苗干重有显著促进作用,相应的最大促进率分别为34.96%、18.93%和20.89%,1 000～4 000μg·mL-1的水提取物对其幼苗根长以及2 000～4 000μg·mL-1的水提取物对其幼苗苗高和干重有显著抑制作用,相应的最大抑制率分别为28.11%、12.40%和27.29%。

Allelopathic potential of the extracts from alien invasive plant Bidens frondosa

Allelopathic activities of Bidens frondosa were studied by investigating the effects of its extracts on seed germination and seedling growth of Melilotus officinalis,Plantago virginica,Ageratum conyzoides and Kummerowia striata by bioassay in laboratory.The results showed that,250-4 000 μg·mL-1 ethanol extracts significantly inhibited seed germination rates of P.virginica and A.conyzoides,the same as 500-4 000 μg·mL-1 aqueous extracts for A.conyzoides,the highest inhibition rates were 60.80%,48.08% and 63.64% respectively.250-1000 μg·mL-1 ethanol extracts and 250-2000 μg·mL-1 aqueous extracts had significant promotion on seedling root length of M.officinalis,the same as 250-500 μg·mL-1 ethanol extracts and 250-2 000 μg·mL-1 aqueous extracts on its seedling height,the highest promotion rates were 32.99%,54.45%,11.55% and 18.12% respectively,but 4000 μg·mL-1 ethanol extracts significantly inhibited its seedling root length,with the inhibition rate of 22.32%.1 000-4 000 μg·mL-1 aqueous extracts and 2 000-4 000 μg·mL-1 ethanol extracts showed significant inhibition on seedling root length of P.virginica,the same as 4000 μg·mL-1 ethanol extracts on its seedling height,the highest inhibition rates were 19.96%,33.10% and 23.15% respectively.250-4000 μg·mL-1 aqueous extracts and 1 000-4 000 μg·mL-1 ethanol extracts showed significant inhibition on seedling root length of A.conyzoides,the same as 2 000-4 000 μg·mL-1 ethanol and aqueous extracts on its seedling height,the highest inhibition rates were 60.92%,40.80%,11.31% and 11.65% respectively.250-2 000 μg·mL-1 ethanol extracts significantly promoted the seedling root length and height of K.striata,the same as 1 000 μg·mL-1 ethanol extracts on its seedling dry weight per plant,the highest promotion rates were 34.96%,18.93% and 20.89% respectively,but 1 000-4 000 μg·mL-1 aqueous extracts siginificantly inhibited its seedling root length,the same as 2 000-4 000 μg·mL-1 aqueous extracts on its seedling height and dry weight per plant,the highest inhibition rates were 28.11%,12.40% and 27.29% respectively.