胜红蓟挥发物对杂草和蔬菜的化感作用

Allelopathic Potentials of Volatiles fromAgeratum conyzoides L.on Weeds and Vegetables

为了揭示潮汕地区重要外来入侵物种胜红蓟的入侵机制,采用水蒸气蒸馏法提取胜红蓟地上部分的挥发油,以稗草、黑麦草、三叶鬼针草3种杂草和白菜、油菜、萝卜3种蔬菜的种子为供试对象,用种子萌发法测定胜红蓟挥发油和茎叶自然挥发物的化感作用。结果表明:胜红蓟的茎叶在密闭系统中产生的挥发性物质对6种受体植物的幼苗生长均产生显著的抑制作用,其中对根生长的抑制更为明显。通过水蒸气蒸馏法所得的挥发油在未直接接触受体的条件下对6种植物的幼苗生长也表现显著的抑制作用,且抑制作用随着挥发油用量的增加而增强。胜红蓟挥发物具有化感作用,这可能是其抑制周围其他植物生长的原因之一。

To explore the invasive mechanism of the important alien plant,Ageratum conyzoides L. in Chaoshan area, the allelopathic potentials of A. conyzoides L. volatiles were determined by investigating the seed germination and seedling growth of 3 weeds, Echinochloa crusgalli （L.） Beauv. ,Lolium perenne L. ,Bidens pilosa L. ,and 3 vegetables,Brassica campestris L. ,Brassica chinensis L. , Raphanus sativus L. Results showed that the volatiles released from leaves and stems of A. conyzoides L. in an airproof system significantly inhibited the seedling growth of the 6 plants, especially the growth of roots. Essential oil obtained from the steam distillation of fresh leaves and stems also significantly inhibited the seedling growth of the 6 tested species without direct contact with the receptor. The inhibition of the essential oil enhanced with increase of its concentration. The results above indicate that volatiles of A. conyzoides L. have allelopathic poten- tials,which may serve as an important mechanism of successful invasion of this alien species.