In order to study allelopathy of tobacco root exudates,we conducted Petri dishes filter method under the aseptic conditions to culture the lettuce seeds（Lactuca sativa） and tobacco seeds which had the high sensitivity with the allelopathy,and to study the effects of tobacco root exudates on the seed germination and seedlings.The results showed：there were significant differences of the fresh weight,dry weight,hypocotyl length and growth potential between lettuce seeds treated with tobacco root exudates and the contrast（P〈0.05） and the resp...
