不同来源鱼腥草水提液的化感效应研究*

 鱼腥草水提液对莴苣、萝卜、白菜的化感作用基本相似，表现为高浓度抑制生长，随着浓度的降低其抑制作用逐渐下降，甚至促进生长。当浓度为1∶10（质量比）时，地上部水提液对莴苣根长抑制率建阳黄坑鱼腥草达77.5%，对莴苣茎长的抑制率建阳黄坑鱼腥草为43.7%；对萝卜根长的抑制率建阳小湖镇鱼腥草为59.9%；地下部水提液对萝卜茎长的抑制率建阳黄坑鱼腥草为46.7%；对白菜根长的抑制率建阳黄坑鱼腥草地上部水提液最大为75.8%，对白菜茎长的抑制率建阳黄坑鱼腥草的地上部水提液最强达68.5%。鱼腥草水提液对三种受体植物根的化感作用比对茎更强，根长抑制率更适宜作为化感作用生测指标。鱼腥草水提液分别经极性树脂ADS-21和非极性树脂ADS-5吸附后，ADS-21洗脱液对莴苣、萝卜、白菜的根长、茎长的抑制作用减弱；而ADS-5洗脱液对莴苣、萝卜、白菜的根长、茎长的抑制率增强。因此认为鱼腥草水浸提液中起化感作用的物质可能以非（弱）极性物质为主，极性物质减弱了非（弱）极性物质的化感作用。

Study on Allelopathic Effect of Water Extraction Solutions of Hottuynia cordata Thunb from Different Sourses

A Similar trend of allelopathy on lettuce, carrot and cabbage was found on the water extraction solution (WES) of the underground and aboveground parts of Houttuynia cordata Thunb, that was, high concentration of WES suppressed the growth of the plants, and the inhibition decreased as the concentration decreased, sometimes WES even stimulated the growth of the plants in low concentration. At the concentration of 1∶10 (mass ratio), the WES of the aboveground parts (AWES) inhibited lettuces root growth at the rate of 77.5%, and the inhibitory ratio (IR) of the stem height of the lettuce was 43.7% in the WES of H.cordata from Huangkeng Town, Jianyang County, while the IR of the root length of the carrot was 55.9% in the WES of H.cordata from Xiaohu Town, Jianyang County. The WES of the underground (UWES) part inhibited the stem height of the carrot at the rate of 46.7%, and the IR of the root length of cabbage (75.8%) was the highest in the UWES of H.cordata from Huangkeng Town, Jianyang County. The IR of the stem height of cabbage (68.5%) was the highest in the AWES of H.cordata from Huangkeng Town, Jianyang County. As far as the 3 plants were concerned, a higher IR was found in root growth than that in stem, which implied that the IR of root length was a more suitable index for the bioassay of allelopathy. After WES was eluted by polar resin ADS-21 and by non-polar resin ADS-5, the suppression of the elution solution of ADS-21 to the root and stem growth was weaker than the non-eluted WES, while the suppression of the elution solution of ADS-5 to the root and stem growth was stronger than the non-eluted WES. It was supposed that non-polar substance played an important role in allelopathy, while polar substance could weaken the allelopathy.