胜红蓟化感作用研究Ⅰ.水溶物的化感作用及其化感物质分离鉴定

Allelopathy of Ageratum conyzoides Ⅰ.Allelopathy of Ageratum conyzoides aqueous extract and isolation and identification of its allelochemicals.

研究了胜红蓟水溶物对植物的化感作用 .结果表明 ,胜红蓟水溶物溶液浓度在0 .2 5gFW·ml- 1 时对所有供试植物的萌发和幼苗生长均有显著的抑制作用 ,浓度降至0 .1 0 gFW·ml- 1 时其抑制作用基本消失 ;胜红蓟不同器官、不同生育期水溶物的化感作用是有差异的 ,特别是不同生境条件下生长的胜红蓟水溶物化感作用有显著差异 ,表明在恶劣生境下胜红蓟的化感作用更为强烈 .对胜红蓟水溶物中的化感活性物质进行分离和分子结构鉴定 ,得到早熟素Ⅰ、早熟素Ⅱ和 5,2 2 二烯 3β 豆甾醇 3个化感化合物 .

Studies on the allelopathy of Ageratum conyzoides aqueous extract showed that the aqueous extract significantly inhibited seed germination and seedling growth of all tested plants at 0.25 g FW·ml -1 ,but the inhibition disappeared at 0.10 g FW·ml -1 . The allelopathic potential of aqueous extract from different organs of A.conyzoides and from its different development stages, especially from different habitats, was different. Ageratum conyzoides growing in adverse habitat showed a stronger allelopathic potential.Three allelochemicals from aqueous extract,e.g. precocene Ⅰ,precocene Ⅱ and stigmast 5,22 diene 3 β ol,were isolated and identified.