香茅,胜红蓟和三叶鬼针草植物他感作用研究

香茅是重要的香料作物，胜红蓟和三叶鬼针草是华南地区重要杂草。本研究证实了这３种植物水抽提物对萝卜，水稻和黄瓜３种受体种子萌发和幼苗生长的植物他感抑制作用。测定了水抽提物的作用浓度，受体中萝卜对他感作用物抑制的反应最敏感。在种子萌发率，幼苗根长和苗高３个测试项目中，幼苗根长对他感作用物抑制的反应量敏感。

STUDY ON ALLELOPATHIC POTENTIALS OF Cymbopogon citratus, Ageratum conyzoides AND Bidens pilosa

Cyrnbopogon citratus is an important perfume crop in the tropics and subtropics, Ageratum conyzoides and BiAens pilosa are the two ecologically well adapted weeds in South China. The allelo-pathic effects of the aqueous extracts of the three donor plants on the seed germination and seedling growth of three acceptor plants: radish ( Raphanus sativus ), rice ( Oryza sativa ) and cucumber ( Cucumis sativus ), were demonstrated. The inhibitory effects of the aqueons extracts with different concentrations were determinated. The experiment excluded the effects of the osmotic pressure and pH of the aqueous extracts. In terms of sensitivity. the acceptor plants and tested items varied in response to allelochemicals. Radish was the most sensitive acceptor plant among the three, and growth of radicle was the most sensitive items among the three tested items: germination, the growth of radicle and shoot of seedling.